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10 September 2021, Volume 42 Issue 9

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Cover and Content of Chemical Journal of Chinese Universities Vol.42 No.9(2021)

2021, 42(9):  1. 

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Review

Recent Progress of Versatile Metal Graphitic Nanocapsules in Biomedical Applications

ZHU Zhaotian, LI Shengkai, SONG Minghui, CAI Xinqi, SONG Zhiling, CHEN Long, CHEN Zhuo

2021, 42(9):  2701-2716.  doi:10.7503/cjcu20210118

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Versatile metal graphitic nanocapsules have aroused extensive research interest in biomedicine due to their superior stability， good biocompatibility and unique physicochemical properties. Based on the unique Raman scattering characteristic peaks of the graphitic shell as a Raman label or internal standard， combining the superior surface enhanced Raman scattering（SERS） and two-photon luminescence（TPL） performance of the plasmonic nanocore， SERS bioanalysis and Raman/TPL dual-modal imaging of tumor cells or tissues have been realized. Based on the graphitic shell with large specific surface area as the drugs loading platform， combining the near?infrared light absorption capacity of the plasmonic nanocore， light-mediated pathogen killing and synergistic hyperthermia and chemotherapy of cancer cells or solid tumors have been realized. In addition， fluorescence detection of biomolecules has been realized based on the excellent fluorescence quenching performance of the graphitic shell； separation and enrichment of biological samples， in-situ magne-tic resonance imaging detection of bacteria and magnetic targeted oral drug delivery in stomach have been rea-lized based on the unique magnetic properties of magnetic nanocore. This review firstly introduces the preparation， classification and properties of metal graphitic nanocapsules， then outlines the recent progress of their extensive applications in biodetection， bioimaging and therapy， and further summarizes their development status including biotoxicity study and pros， cons in biomedicine， their future prospects in biomedical applications are eventually highlighted. We expect the versatile metal graphitic nanocapsules will offer a robust nanoplatform for future clinical biomedical applications.



Inorganic Chemistry

Luminescence Property and LED Device Application for Color-tunable Ca₂LaTaO₆∶Dy³⁺，Sm³⁺ Phosphor Based on Energy Transfer

YUAN Bo, QI Chaochao, ZHANG Xiangting, LUAN Guoyan, ZOU Haifeng

2021, 42(9):  2717-2724.  doi:10.7503/cjcu20210380

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A series of Dy³⁺， Sm³⁺ co-doped double perovskite Ca₂LaTaO₆ （CLTO） white light emitting diodes（WLED） phosphors with tunable color was designed by solid state reaction method. The crystal structure parameters of Ca₂LaTaO₆ and the lattice occupation for Dy³⁺， Sm³⁺ ions in the host were determined through Rietveld refinement， and the band gap was calculated by density functional theory（DFT）. Meanwhile， the energy migration from Dy³⁺ to Sm³⁺was confirmed by the aids of emission/excitation spectra and luminescent decay measurements. The mechanism of energy transfer was explored to be the resonant type via a dipole-dipole interaction and the critical distances between Dy³⁺ and Sm³⁺ were calculated to be 1.176 nm. Based on the energy transfer for Dy³⁺→Sm³⁺， by tuning the molarity ratio of doping Dy³⁺/Sm³⁺ ions， multicolor emission from yellow to yellow-red and white light shall be achieved in Ca₂LaTaO₆∶Dy³⁺， Sm³⁺ phosphors. Finally， white light-emitting diode prototypes were fabricated using as-prepared phosphors and UV chips， the luminescence efficiency， CIE chromaticity coordinates， correlated color temperature（CCT） and color rendering index （CRI） of the LED prototype were exhibited. The results indicated that these phosphors had potential application in UV white LED.



Synthesis and Fluorescence Properties of Novel Ce³⁺-doped Manganese Phosphite Open-framework Materials

HONG Yangyu, XING Hongzhu, BING Qiming, GAO Xuwen, QI Bin, CHEN Yakun, SU Tan, ZOU Bo

2021, 42(9):  2725-2733.  doi:10.7503/cjcu20210115

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A series of novel Ce³⁺-doped manganese phosphite （NH₄）₄［Mn_4-xCe_x（HPO₃）₆］（JIS-10∶Ce³⁺） inorganic open-framework materials was prepared under ionothermal conditions. The synthesized compounds were characterized by means of powder X-ray diffraction（PXRD）， scanning electron microscopy（SEM）， energy dispersive spectroscopy（EDS）， X-ray photoelectron spectroscopy（XPS）， Fourier transform infrared （FTIR） spectroscopy and photoluminescence（PL） spectroscopy. The influences of Ce³⁺ doping concentration， reaction temperatures and reaction time on the luminescence property were studied under 260 nm excitation. A green emission band at 500 nm of Ce³⁺ and a yellow emission band at 590 nm of Mn²⁺ were observed. At low doping level of 0.06 Ce³⁺， the phosphor had a yellow-green emission with the CIE coordinate of （0.38， 0.48）. The green emission band grew more dramatical than the yellow one when the doping concentration of Ce³⁺ ion was increased， leading to the tunable color-emission. The excitation competition between Ce³⁺ and Mn²⁺， as well as the energy transfer between these species were also studied. The strongest emission was observed at x=1.33， higher than which concentration quenching occurred.



Liquid Phase Assembly of Mesoporous Cs_xH_3-xPW₁₂O₄₀ and Characterization of Their Acidity

WANG Meiyin, HUANG Daofeng, CHEN Xin, ZHOU Junfu, REN Yuanhang, YE Lin, YUE Bin, HE Heyong

2021, 42(9):  2734-2741.  doi:10.7503/cjcu20210102

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A series of mesoporous Cs_xH_3-xPW₁₂O₄₀ samples（denoted as m-CsPW） has been prepared using H₃PW₁₂O₄₀， CsCl as raw materials and amphiphilic triblock copolymer F127 as template. The sampleswere characterized by means of powder X-ray diffraction（XRD）， field emission scanning electron microscopy （FESEM）， field emission transmission electron microscopy（FETEM）， N₂ adsorption-desorption measurement and small angle X-ray scattering（SAXS） spectroscopy. The results indicate that the m-CsPW particles consis-ting of crystallographically ordered nanocrystallites are mesoporous spherical materials. Acid density and strength of the samples before and after acid treatment were characterized by ³¹P magic-angle spinning NMR spectroscopy（³¹P MAS NMR） using trimethylphosphine as probe molecule. Taking the Pechmann condensation of 5，7-dihydroxy-4-methylcoumarin as a model reaction， the relationship between the acid properties of the samples and the catalytic activity of the reaction has been investigated.



Post-synthesis of Ti-MWW Zeolite via Titanium Incorporation in Liquid Acid Solution

LUO Qiangqiang, JIN Shaoqing, SUN Hongmin, YANG Weimin

2021, 42(9):  2742-2751.  doi:10.7503/cjcu20210070

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B-MWW zeolite precursor was first hydrothermally synthesized with less amount of boric acid and piperidine under the condition of sodium hydroxide introduced， and then the incorporation of titanium was performed in liquid acid solution to obtain Ti-MWW zeolite with high crystallinity. With the help of powder X-ray diffraction， N₂ adsorption-desorption characterization， UV-Vis and UV Raman spectroscopies， the effects of parameters including Si/Ti ratio and temperature on the texture properties， the state of titanium species and the catalytic performance in 1-hexene epoxidation of obtained Ti-MWW zeolite were investigated. The Si/Ti ratio and temperature beneficial for titanium incorporation are 30 and 373 K， respectively. Moreover， the catalytic performance of the obtained Ti-MWW zeolite in 1-hexene epoxidation can be significantly improved with a small amount of ammonium fluoride added during post-synthesis. This study not only demonstrates the deboration-based titanium incorporation mechanism during acid treatment of Ti-MWW zeolite precursor， but also provides a new method for the synthesis of Ti-MWW zeolite.



Analytical Chemistry

Theoretical Study on the Structures and Properties of Flavonoids in Plantain

HUANG Luoyi, WENG Yueyue, HUANG Xuhui, WANG Chaojie

2021, 42(9):  2752-2765.  doi:10.7503/cjcu20210180

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The ωB97XD/6-311+G（2d，p） method in Density Functional Theory（DFT） was used to quantitatively calculat the flavonoids in plantain， to explore the structure-activity relationship of this class of compounds and to studied the geometric structure， spectral properties and electronic structure of 13 kinds of flavonoids from plantain and dihydromyricetin. Then the reactivity indexes analysis were carried out using conceptual density functional theory. At last the pharmacokinetic platform was used to evaluate the drug-like. Based on the results of the geometry analysis， it was initially estimated that the antioxidant order of 14 flavonoids was： 10>12≈7>13>6>4> 14≈9≈8>11>5>3≈2>1. The fitting result of nuclear magnetic resonance spectroscopy（NMR） showed that the theoretical value of NMR obtained by this method was in good agreement with the experimental value（R²>0.95）. The results of electrostatic potential map on molecular surface showed that the minimum points of electrostatic potential of 14 flavonoids were near carbonyl oxygen， while the maximum points were near hydroxyl hydrogen. It was found that the maximum values on the opposite hydroxyl groups on the B ring were greater than C and A rings. According to the results of the global reactivity descriptor， it was found that the chemical potentials of compounds 1， 2， 4， 11 and 12 were lower， and the electronegativity， electrophilic index while hardness were higher， which indicating these 5 compounds had better stability and reactivity. The local reactivity descriptor further identified the nucleophilic/electrophilic reaction sites of 14 compounds. Finally， the pharmacokinetic results screened out that compounds 1， 3， 4， 6， 12 and 13 may be as possible alternatives to dihydromyricetin drug. In the end， compounds 4 and 12 were found to have the most potential as medicines， and further experimental studies could be carried out.



Organic Chemistry

Design， Synthesis and Antifungal Activity of Novel Isoquinoline Derivatives

ZUO Huailong, LEI Simin, ZHANG Rui, LI Yuxin, CHEN Wei

2021, 42(9):  2766-2771.  doi:10.7503/cjcu20210313

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Based on biomimetic synthetic strategy and reasonable pharmacophore splicing， fifteen novel isoquinoline derivatives were designed and synthesized by introducing the active fragment of diphenyl ether into the 3，4-dihydroisoquinoline skeleton. Their chemical structures were confirmed by nuclear magnetic resonance（NMR） and high resolution mass spectrometry（HRMS）. In vitro antifungal activity results showed that at 50 mg/L， the inhibition rates of compounds Ic， Ie and Il against Physalospora piricola and Rhizotonia cerealis were as high as 93.0%， which were better than Sanguinarine and equivalent to Chlorothalonil. The inhibition rate of compound Il against Fusarium graminearum was 83.3%， which was much better than Sanguinarine（64.2%） and Chlorothalonil（57.7%）. In addition， the inhibition rate of compound Il against five plant pathogens was higher than that of Sanguinarine.



Na₂CO₃-catalyzed 1，6-Conjugate Addition of Trimethylsilyl Azide to δ-CF₃-δ-Aryl-disubstituted Para-Quinone Methides： Efficient Construction of Diarylmethanes Bearing CF₃- and N₃-Substituted Quaternary Stereocenters

LIU Huazheng, PAN Xiaoguang, LI Hua, WAN Renzhong, LIU Xigong

2021, 42(9):  2772-2781.  doi:10.7503/cjcu20210297

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Organic azides have emerged as significant and versatile reactants in organic synthesis and have been widely used in the field of chemical biology， pharmaceutical discovery， and materials science. Trifluoromethylated compounds were recognized as key structural motifs in bioactive molecules and synthetic pharmaceuticals. The incorporation of a trifluoromethyl group into organic molecules is often beneficial for improving their physiochemical properties such as metabolic stability， lipophilicity， and bioavailability. As a consequence， the development of efficient methods for the synthesis of molecules containing both the trifluoromethyl group and the azide group is highly desired. However， only a few of synthetic methods were reported for the synthesis of these structures. On the other hand， diarylmethane derivatives spread across natural products， pharmaceuticals and functional materials， and their synthesis was attracted great attention owning to the diverse biological and medical properties. Described is an efficient azidative aromatization process of δ-CF₃-δ-aryl-disubstituted para-quinone methides with trimethylsilyl azide. Using Na₂CO₃ as catalyst， 1，6-conjugate addition of trimethylsilyl azide to δ-CF₃-δ-aryl-substituted para-quinone methides went smoothly， delivering diarylmethanes bearing δ-CF₃- and N₃-substituted stereocenters in excellent yields. Moreover， the reaction displays a broad substrate scope and excellent functional group tolerance.



Synthesis of Ursodeoxycholic Acid from Dehydroiso-androsterone 3-Acetate

CHEN Wang, HU Daihua, LIU Gege

2021, 42(9):  2782-2788.  doi:10.7503/cjcu20210277

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A new method for the synthesis of ursodeoxycholic acid from commercial plant-source materials was developed. Ursodeoxycholic acid was synthesized from dehydroepiandrosterone 3-acetate in 9 steps through a regioselective allyl oxidationat， Mistunobu reaction and Luche reduction as the key steps， with an overall yield of 38.6%. The key intermediate 4 was prepared in good yield by improved allylic oxidation of compound 3. The reaction conditions of the key allyl oxidation reaction were also investigated and optimized， including solvent， oxidant and reaction temperature. Since all starting materials are cost-effective， commercially available and effectively avoided the risk of animal derived raw materials， this promising synthetic route offers economical and efficient strategies for potential production of Ursodeoxycholic Acid.



Synthesis and Biological Activity of Lycorine Derivatives Containing Malate Ester

ZHAO Ying, QIAO Ling, ZHAO Guofeng, CHEN Li

2021, 42(9):  2789-2797.  doi:10.7503/cjcu20210264

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Several lycorine derivatives containing substituted malic acid ester segment were designed and synthesized with physiological activite lycorine as the lead compound. All new compounds were characterized by means of high resolution mass spectrometry， nuclear magnetic resonance spectroscopy， optical rotation and circular dichroism. The results of preliminary study of the antitumor activities showed that these compounds possess a significant reduction in the toxicity to normal cells while maintaining lycorine antitumor activity. This research laid a foundation for design of new type of high activity and low toxicity lycorine derivatives.



Novel Approach to Isatins via Pd-Cu Catalyzed Oxidative Transformation

GUO Yang, LIN Kai, XIE Kaiqiang, LIU Sheng

2021, 42(9):  2798-2804.  doi:10.7503/cjcu20210260

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A new method of synthesizing isatin was developed and applied to the substrate extension to get a series of isatin compounds. Using N-alkyl substituted acrylanilide compounds as raw materials， in palladium acetate， cuprous iodide and under the catalysis and participation of oxygen， N-alkylated isatin derivatives could be synthesized with the yields of 42%—87%. Using this method， 23 isatin compounds were prepared and the possible reaction mechanism was proposed. This synthetic route reduces the use of protecting groups and is simple and efficient.



Sc（OTf）₃ Catalyzed 1，6-Conjugate Allylation of δ-CN p-QMs： Synthesis of Allyl Substituted Diarylacetonitrile Compounds

HU Chuanchuan, PANG Jingxiang, HE Chuangchuang, LI Wei, SUN Shutao

2021, 42(9):  2805-2814.  doi:10.7503/cjcu20210215

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Sakurai allylation is one of the most important methods for the construction of carbon-carbon bonds， which shows a wide range of applications in the synthesis of bioactive molecules. The addition of allyl silane to carbonyl and imine groups， which could be used to prepare homoallyl alcohols or homoallylamines， has been well studied. Similarly， the addition of allyl silane to α， β-unsaturated carbonyl compounds has also been widely explored. However， the 1，6-addition of allyl silane to diketene compounds have always been a major challenge in this field， and current research is still mainly mediated by stoichiometric strong Lewis acid. In recent years， p-quinone methides（p-QMs）， as a special electrophilic reagent， has attracted wide attention of synthetic chemists and plays a very important role in the synthesis of natural products and pharmaceutical chemistry. The unique conjugated structure of diketene in the skeleton of p-QMs， and the driving force of aromatization after nucleophile addition lays a foundation for its high regioselectivity 1，6-conjugated addition. We envision that the allylation of p-QMs by 1，6-conjugate addition would afford allyl substituted diarylmethane compounds with potential biological activity. This paper reported the Sc（OTf）₃ catalyzed 1，6-conjugate addition of δ-cyano-δ-aryl substituted p-QMs with allyltrimethylsilane. A series of allyl substituted diaryl acetonitriles with quaternary centers was prepared. The operation of this reaction was simple and the reaction condition was mild. The results showed good substrate scope and functional group compatibility. At the same time， the synthetic potential of the method was demonstrated by the derivation of nitrile and allyl groups， respectively.



Synthesis and Properties of Energetic Plasticizer 2，2-Dinitropropyl Trifluoropropanoate

ZHAO Baodong, LIU Yajing, PAN Yongfei, LIU Weixiao, GAO Fulei, WANG Yinglei

2021, 42(9):  2815-2823.  doi:10.7503/cjcu20210137

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With nitroethane as starting material， energetic plasticizer 2，2-dinitropropyl trifluoropropanoate（DNPTFP） was designed and synthesized via condensation reaction， oxidation reaction and esterification reaction. Its structure was characterized and confirmed by means of nuclear magnetic resonance（NMR）， Fourier transform infrared spectroscopy （FTIR） and elemental analysis. Optimization on the synthesis process of DNPTFP was conducted， and the optimal reaction conditions for the esterification reaction were determined as follows： taking toluene as reaction solvent， n（2，2-dinitropropan-1-ol）∶n（trifluoropropanoic acid）=1∶1.10， the addition of concentrated H₂SO₄ catalyst was 5.0%（mass fraction）， the reaction temperature was 110 ℃， the reaction time was 10 h， and the yield and purity of DNPTFP was 75.2% and 99.0%， respectively. Thermal analysis determined that the glass transition temperature （T_g） was -80.5 ℃ and thermal decomposition peak temperature was 267.59 ℃. While mechanical sensitivities showed that the impact sensitivity was measured as H₅₀=125.9 cm， the friction sensitivity was 0. Those results indicated that DNPTFP had good thermal properties as well as insensitive mechanical sensitivities. Besides， as miscibility test， viscosity and T_g measurements turned out， DNPTFP had good miscibility with glycide azide polymer（GAP）， and demonstrated notable adjust ability on the viscosity and T_g of GAP. Moreover， along with higher mixing ratio of DNPTFP， lower fluidity activation energy and higher plasticizing efficiency was achieved. Therefore， DNPTFP exhibited excellent plasticizing effect on GAP， which indicating good potential application in GAP based explosives and propellant.



Physical Chemistry

Urchin-like Gold Nanoneedle for Efficient Electrocatalytic CO₂ Reduction

ZHANG Xiang, XIE Xulan, XIONG Likun, PENG Yang

2021, 42(9):  2824-2831.  doi:10.7503/cjcu20210408

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Electrocatalytic CO₂ reduction is one of the effective strategies to solve today’s energy and environmental crisis， in which reducing CO₂ to CO is the first and the most critical step. However， the low solubility of CO₂ in electrolyte greatly limits its reaction dynamics and product selectivity. In this work， a seed-mediated growth method without any surfactants was applied to synthesize gold nanoparticles with an urchin-like structure. The electric field at the tip of the needle can effectively enrich electrolyte cations and increase the local concentration of CO₂， thereby increasing the current density and Faraday efficiency（FE_CO） of the catalyst， which can reach 96% at -0.6 V（vs. RHE）. Electrochemical performance tests have also shown that the high selectivity is attributed to its unique needle structure and surface defects.



Potassium Poisoning Mechanism of Cu-SAPO-18 Catalyst for Selective Catalytic Reduction of NO_x by Ammonia

MENG Fanwei, GAO Qi, YE Qing, LI Chenxi

2021, 42(9):  2832-2841.  doi:10.7503/cjcu20210360

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The effects of different hydrothermal aging temperatures on the structure and catalytic activity of NH₃-SCR of K poisoned 0.4K-Cu-SAPO-18 samples were studied. The results showed that K poisoning had little effect on the structure of the samples， but the NH₃-SCR performance was significantly reduced. At 350 ℃， the NO conversion rate of 0.4K-Cu-SAPO-18 was 65.88%， which was significantly lower than 90.85% of the unpoisoned Cu-SAPO-18 sample. The hydrothermal aging temperature obviously affected the structure of the catalyst， reducing active sites and surface acidity. As the hydrothermal aging temperature increases， the AEI structure of the catalyst was destroyed， the active species decreased， and the catalytic activity decreased significantly. H₂-TPR results showed that the total amount of isolated Cu²⁺ and Cu⁺ varied from 66.61 and 1.32 μmol/g for unpoisoned Cu-SAPO-18 samples to 39.52 and 101.96 μmol/g for K poisoned 0.4K-Cu-SAPO-18 samples， respectively， indicating that isolated Cu²⁺ was easily converted to Cu₂O in K poisoned samples. After K poisoning， the number of weak acid sites， medium strong acid sites and strong acid sites decreased， from 0.201， 0.103 and 0.302 mmol/g for unpoisoned Cu-SAPO-18 sample to 0.102， 0.086 and 0.071 mmol/g for poisoned 0.4K-Cu-SAPO-18 sample， respectively. The results of NH₃-TPD and in situ IR showed that K competitively replaced isolated Cu²⁺ and H⁺ in the catalyst［K⁺+Si—O（Cu²⁺）—Al → Si—O（K⁺）—Al+Cu²⁺， K⁺+Si—O（H⁺）—Al → Si—O（K⁺）—Al+H⁺］， and decreased the active and acidic sites of 0.4K-Cu-SAPO-18 sample， which resulted in the decrease of its catalytic activity. In the low temperature NH₃-SCR reaction， Elye-rideal（E-R） and Langmuir-Hinshelwood（L-H） mechanisms were performed for both K poisoned and unpoisoned samples， and the Langmuir-Hinshelwood mechanism was dominant. However， the reaction rate of K poisoning samples decreased significantly.



Theoretical Investigation of Hydrogen Storage Properties of Sc， Ti， V-decorated and B/N-doped Monovacancy Graphene

MA Lijuan, GAO Shengqi, RONG Yifei, JIA Jianfeng, WU Haishun

2021, 42(9):  2842-2851.  doi:10.7503/cjcu20210354

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3d Transition-metal decorating is the most effective way to improve the hydrogen storage performance of graphene. However， metal agglomeration and dissociation of H₂ greatly limit their application. In this paper， B/N doping was proposed to avoid the above two problems. Density functional theory calculations show that the binding energy of Sc can be greatly increased by B/N doping. Both Sc/BMG and Sc/NMG can be used as potential hydrogen storage materials because the first adsorbed H₂ is molecular. Sc/BMG could adsorb 5H₂ with the average hydrogen adsorption energy of -0.18─-0.43 eV. The H₂ adsorption sites of BMG could be increased by forming multiple Sc/C₃B₂ units. Sc/NMG could adsorb 6H₂ with the average hydrogen adsorption energy of -0.17─-0.29 eV. The hydrogen storage capacity of Sc/NMG could be further improved by the formation of Sc/N₃/Sc units.



Preparation and Supercapacitive Performance of Naphthalene-based Interconnected Porous Carbon Nanocapsules

WEI Yuchen, WU Tingting, YANG Lei, JIN Biyu, LI Hongqiang, HE Xiaojun

2021, 42(9):  2852-2860.  doi:10.7503/cjcu20210336

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Porous carbon materials volume densities are usually less than 0.5 g/cm³， resulting in that porous carbon materials have a low volume specific capacitance. Therefore， it is still a big challenge to improve volume specific capacitance performance of carbon materials. Herein， interconnected porous carbon nanocapsules（ICNC） were prepared by MgO template induction coupled with KOH tailoring technology using naphthalene as carbon source. The as-prepared ICNC₂ has a large specific surface area（1811 m²/g）， high compaction density（1.38 g/cm³） and micropore volume content（58.93%）. In a symmetrical supercapacitor， the ICNC₂ electrode displays a high volumetric capacitance of 420.8 F/cm³ at 0.069 A/cm³ and retains 315.1 F/cm³ at 27.6 A/cm³ with capacitance retention of 74.82%. The supercapacitor device of ICNC₂ electrode displays a high volumetric energy density of 14.6 W·h/L at the power density of 38 W/L. It also shows excellent cycle stability with only 1.4% decay and outstanding coulombic efficiency of 99.1% after 20000 cycles. This work provides a feasible method for production of high-performance carbon nanocapsules from small aromatic molecules for energy storage.



Synthesis of a Dual-lithium-salt Comb Polymer Electrolyte and Its Electrochemical Performance

YANG Yingjie, ZHANG Xiaorong, SUN Yuxue, LIU Jun, XIE Haiming

2021, 42(9):  2861-2868.  doi:10.7503/cjcu20210309

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Polyethylene glycol monomethyl ether（MPEG） was grafted on poly（isobutylene-alt-maleic anhydride）（PIAMA） to synthesize comb-like lithium mono-ion conductor PIAMA-g-MPEG， which was mixed with lithium bis （trifluoromethylsulfonyl）imide（LiTFSI） to form double-lithium-salt comb polymer electrolyte membrane. Nuclear magnetic resonance（¹H NMR） spectroscopy， thermogravimetric analysis（TG）， scanning electron microscopy（SEM）， electrochemical impedance（EIS） and battery charge-discharge test were used to study the physical， chemical and electrochemical properties of polymer matrix and electrolyte. The results show that the designed double lithium salt comb polymer electrolyte can effectively dissociate and transport lithium ions， the ion mobility t_Li⁺ is 0.32 at 70 ℃， the ion conductivity （σ） is 1.5×10^-4 S/cm， the electrochemical stability window is 0—4.9 V（vs. Li/Li⁺）. The assembled Li|PIAMA-g-MPEG|Li battery and the constant current charge-discharge voltage polarization test at 70 ℃ show that the electrolyte has good compatibility with the metal lithium negative electrode and can effectively inhibit the growth of lithium dendrites. The assembled LiFePO₄|PIAMA-g-MPEG|Li battery was subjected to 70 ℃ long cycle and rate performance test， and the electrolyte showed excellent high temperature performance.



Effect of A Site-deficiency on the Structure and Catalytic Oxidation Activity of the La-Sr-Co-O Perovskite

GAO Zhongnan, GUO Lihong, ZHAO Dongyue, LI Xingang

2021, 42(9):  2869-2877.  doi:10.7503/cjcu20210311

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The La-Sr-Co-O perovskite was prepared by citrate acid complex method， and then the Sr ions was selectively dissolved to obtain A site-deficient perovskite. The changes of phase structure， coordination environment and electronic properties of the A site-deficient perovskite were investigated by powder X-ray diffraction（XRD）， X-ray absorption fine structures（XAFS）， inductively coupled plasma-optical emission spectro- scopy（ICP-OES）， X-ray photoelectron spectroscopy（XPS） and Raman spectra characterization techniques. The corresponding catalytic activity was also evaluated through the CO and NO oxidation reaction. The results show that Sr-rich region is reconstructed by acid treatment through selective dissolving SrCO₃ and SrO. The deficiency of Sr（A-site） lead to the exsolution of Co in the form of new Co₃O₄ phase. More oxygen vancancies were also generated， which facilitates the generation of oxygen vacancy and activation of the lattice oxygen species. Therefore， the A site-deficient perovskite performed better CO and NO oxidation ability under low temperatures.



Theoretical Study on Direct Conversion of CH₄ and CO₂ into Acetic Acid over MCu₂O_x（M = Cu²⁺， Ce⁴⁺， Zr⁴⁺） Clusters

ZHONG Shengguang, XIA Wensheng, ZHANG Qinghong, WAN Huilin

2021, 42(9):  2878-2885.  doi:10.7503/cjcu20210282

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Transformation and utilization of methane and carbon dioxide are important to chemical industry of natural（shale） gas and environmental protection. The properties of electroneutral clusters MCu₂O_x（M=Cu²⁺， Ce⁴⁺， Zr⁴⁺； x=3， 4） and their influences on direct conversion of methane and carbon dioxide to acetic acid were investigated by means of density functional theory（DFT）. The clusters-catalyzed reaction consists of C—H activation of methane， C-C coupling by carbon dioxide insertion， CH₃COO rotation， hydrogen transfer. The first 2 steps are essential to the proceeding of the whole reaction， in which C—H and C-C interacted with the active sites of the clusters， respectively， leading to the formation of 4-centered transition states. During this process， electrons transferred to the clusters from methane， and then transferred to carbon dioxide， which activated both C—H bond of CH₄ and C=O bond of CO₂， and then drove C-C coupling. With introducing of Ce or Zr， the clusters displayed the structure not only with 6-membered ring（I）， but also double 4-membered ring with Ce or Zr located in the center（II） or end（III）. The structures and electron spin states of the clusters are associated with the reactivity. It was found that the clusters with low spin states preferred to C—H activation， and the ones with high spin states tended to C-C coupling. Among the doped clusters with three types of structures， the cluster III at triplet state well matches C—H activation with C-C coupling in the targeted reaction. Comparing the clusters with/without doping for the same structure and electron spin state， the local charge at active sites was changed with the doping of Ce or Zr into copper oxide clusters. This weakened slightly the ability of the clusters in activating C—H bond of methane， but decreased significantly Gibbs free barrier for C-C coupling， and then drove well the overall reaction. The doped Zr showed better promoting roles than Ce in this process.



Synthesis of NiO_x-ZSM-5 Composite Materials and Its Electrocatalytic Hydrogen Evolution Performance in Microbial Electrolysis Cell

GAO Xiaole, WANG Jiaxin, LI Zhifang, LI Yanchun, YANG Donghua

2021, 42(9):  2886-2895.  doi:10.7503/cjcu20210258

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ZSM-5 molecular sieves were synthesized by adding carbon spheres into Na₂O-TPABr-Al₂O₃-SiO₂-H₂O sol reaction system with hydrothermal crystallization method， then loaded different nickel-salts to prepare NiO_x-ZSM-5 composites. The samples were characterized by means of X-ray diffraction（XRD）， scanning electron microscopy（SEM）， transmission electron microscopy（TEM）， X-ray photoelectron spectroscopy（XPS）， nitrogen adsorption-desorption isotherms and electrochemical tests. In addition， their catalytic hydrogen evolution performances were evaluated by the microbial electrolytic cell（MEC）. The results show that the ZSM-5 molecular sieves composed of stacked ZSM-5 nanoparticles under the action of carbon spheres are ellipsoidal morphology， which mesoporous specific surface area and mesoporous pore volume have significantly increased. After immersion and roasting， the speckled NiO_x nanoparticles are covered the mesoporous surface formed by the crystal gap and the surface of the molecular sieve. Compared with pure NiO， the composites with 40% nickel-salts show that the absorption peak of multivalent nickels and oxygen shift to the high energy direction. Eventually the electrocatalytic activities are significantly improved by increasing active sites of multivalent nickel， aluminum atoms and oxygen vacancies， the composites exhibit high current density（8.45 mA/cm²） and low overpotential（151 mV）. During the MEC operation cycle， the average hydrogen evolution current density of the composite is （28.64±7.4） A/m²， the total gas production is （52.67±1.64） mL， and the H₂ purity is （89.07±0.06）%. The hydrogen evolution efficiency（0.571 m³?m^-3?d^-1） and coulombic efficiency［（76.7±5.4）%］ of composite cathode are similar to Pt/C cathode， indicating that the composite is a low cost and high efficiency hydrogen evolution material， which offers a possible alternative to Pt cathode.



g-C₃N₄/CdS/Ni Composite as a Bifunctional Photocatalyst for H₂ Generation and 5-Hydroxymethylfurfural Oxidation

LI Chenchen, NA Yong

2021, 42(9):  2896-2903.  doi:10.7503/cjcu20210255

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The bifunctional photocatalyst g-C₃N₄/CdS/Ni was synthesized by high temperature calcination， in situ growth method and photoreduction method in three steps. The introduction of CdS in this composite can enhance the separation rate of photogenerated holes and electrons. And the loading of Ni can further improve the photoinduced hydrogen production rate. In addition， the photocatalytic hydrogen evolution reaction was carried out in triethanolamine（TEOA， hole sacrificial agent） aqueous solution and the optimal CdS content of the composite was determined. Experiments showed that the composite with 25%（mass fraction） CdS exhibited the best photocatalytic activity and the Ni was a good cocatalyst for hydrogen production. The highest H₂ gene- ration rate catalyzed by g-C₃N₄/25CdS/Ni composite was 4134.5 μmol·g^-1·h^-1， which was 115 times higher than that of g-C₃N₄/Ni composite. Subsequently， the TEOA in this system was replaced by 5-hydroxymethylfurfural（HMF）. HMF can be selectively oxidized to the value-added chemical 2，5-diformylfuran（DFF）. When the conversion of HMF was 82.3% and the selectivity of DFF was 69.4%， the yield of DFF was up to the highest（57.2%）. At the same time， the yield of H₂ in this system was 51.8 μmol/g. In summary， g-C₃N₄/CdS/Ni composite can catalyze photoinduced H₂ evolution and HMF selective oxidation in the same system.



Mechanism of the Removal of Acetylacetone Ligands in Zirconia Wet Gel and Fabrication of Zirconia Aerogel Composites

LI Zhanfeng, LIU Benxue, LIU Xiaochan, WANG Xinqiang, ZHANG Jing, YU Shimo, ZHAO Xinfu, ZHANG Xin’en, YI Xibin

2021, 42(9):  2904-2910.  doi:10.7503/cjcu20210254

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It was reported that the removal of acac ligands can be accelerated by soaking polyacetylacetonato-zirconium（PAZ） wet gel in organic silane（tetramethyl orthosilicate， tetraethyl orthosilicate） or organic borane（triethyl borate）. Moreover， it was confirmed that soaking wet gel in siliane（borane） can accelerate the removal of acac ligands through infrared spectrum， elemental analysis， X-ray photoelectron spectroscopy， chromatography-mass spectrometry， etc. Meanwhile， the mechanism was be deduced. By soaking PAZ wet gel in organic silane， the gel skeleton was strengthened as well. Therefore， nanoporous ZrO₂ aerogels with high specific surface area could be obtained by inexpensive drying techniques. In addition， to prepare the ultra-lightweight silica fiber/zirconia aerogel（SFZA）， the ZrO₂ aerogel matrix was also composite with ultrafine quartz fiber， which further prevents drying shrinkage. Based on the plate heat flow method the lowest thermal conductivity coefficient of the SFZA was 0.042 and 0.063 W?m^-1?K^-1 at 1000 and 1200 ℃， respectively.



An Organic Salt PTO（KPD）₂ with Enhanced Performance as a Cathode Material in Lithium-ion Batteries

BAO Junquan, ZHENG Shibing, YUAN Xuming, SHI Jinqiang, SUN Tianjiang, LIANG Jing

2021, 42(9):  2911-2918.  doi:10.7503/cjcu20210248

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Organic compounds have recently attracted considerable attention as cathode materials in lithiu- mion batteries. However， high solubility in the organic electrolytes will cause a severe capacity deterioration， which limiting their application. Here， a new organic cathode material of pyrene-4，5，9，10-tetraone-di（potassium-pyromellitic diimide）［PTO（KPD）₂］ was obtained through a solvothermal reaction. As a cathode material in lithium-ion batteries， the multi-carbonyl formation gives a considerable practical capacity of 255.8 mA·h/g at a current density of 50 mA/g. Also， PTO（KPD）₂ has a high capacity retention of 81.1% after 800 cycles at 500 mA/g， which shows excellent long-cycle performance. Benefiting from the polar organic salt structure， the solubility of PTO（KPD）₂ in organic electrolytes sharply decreases. This work demonstrates that the structural merits of organic salts is an effective approach to preparing new organic cathode materials applied in lithiumion batteries with better electrochemical performance.



Effects of Additive on the Electrodeposition and Coating Structure in a Novel System of Electronic Copper Electroplating

LI Weiqing, JIN Lei, YANG Jiaqiang, Wang Zhaoyun, YANG Fangzu, ZHAN Dongping, TIAN Zhongqun

2021, 42(9):  2919-2925.  doi:10.7503/cjcu20210225

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Electronic copper electroplating has important applications in the advanced electronic manufactu-ring industry. In this work， the effects of the additive XNS（a mixture of polyamine and nitrogen-containing compounds） on the coating structure in the novel， weakly alkaline and citrate-based multi-coordination system for copper electronic electroplating with low concentration of main salts（10 g/L copper sulfate） was investiga-ted. The constant current deposition experiments indicate that the additive XNS can increase the current efficiency of copper electrodeposition， which achieves 95.4% at a current density of 2.0 A/dm² and increases by 17.5% comparing to the electroplating system without XNS. Electrochemical experiments prove that the additive XNS can change the cathodic reduction of Cu（Ⅱ） cations， i.e.， in presence of XNS which is a one-step two-electron process［Cu（Ⅱ）+2e→Cu］， and in absence of XNS which is a two-step one-electron processes ［Cu（Ⅱ）+e→Cu（Ⅰ）+e→Cu］， and improves the reduction current density of Cu electrodeposition. Although additive XNS can accelerate copper electrodeposition rate， the coating surface of Cu becomes much finer and neater. At the current density of 2.0 A/dm²， the crystal structure of copper coating is reconstructed from Cu（111） facet to Cu（200） facet， presenting highly preferred crystal orientation in the presence of XNS.



Preparation of Z-type g-C₃N₄/Pt/TiO₂ Nanotube Array Composite Electrode and Its Performance of Photoelectric Oxidation of Methanol

XU Xiaolong, FANG Lining, LIU Changyu, LIU Minchao, JIA Jianbo

2021, 42(9):  2926-2933.  doi:10.7503/cjcu20210155

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g-C₃N₄ nanosheets were prepared by blowing dicyandiamide with NH₄Cl as a gas template， and then loaded on Pt/TiO₂ nanotube arrays（Pt/TiO₂ NTs） to prepare a new type of Z-type g-C₃N₄/Pt/TiO₂ NTs composite electrode. The structure of the material was characterized by means of scanning electron microscopy， X-ray diffraction spectrometer， and X-ray photoelectron spectroscopy. Electrochemical and photoelectrochemical methods were used to inspect the characteristics of the materials. The results show that the g-C₃N₄/Pt/TiO₂ NTs composite has an efficient performance of photoelectric oxidation of methanol under visible light irradiation. There are two main reasons for the high performance of g-C₃N₄/Pt/TiO₂ NTs composite： （1） the combination of g-C₃N₄ and Pt/TiO₂ NTs effectively expands the absorption in the visible light range； （2） Z-type charge transfer retains strong oxidation ability of holes and strong reduction of electrons， so that the photo-generated interme-diate acts on the electrocatalytic process and enhances the efficiency of methanol oxidation.



Effects of Substrate Surface Properties and Precursor Chemical Environment on In⁃situ Oriented Construction of Titanium Silicalite Zeolite Membranes

LI Yichuan, ZHU Guofu, WANG Yu, CHAI Yongming, LIU Chenguang, HE Shengbao

2021, 42(9):  2934-2943.  doi:10.7503/cjcu20210092

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b-Oriented MFI zeolite membranes can significantly promote the molecular transport efficiency， so they are widely used in the field of mixture separation and catalysis. Although the traditional in?situ hydrothermal crystallization method is mature， it is still difficult to control the b-orientation growth of the membrane. In this paper， the effects of surface physicochemical properties， precursor ratio and crystallization conditions on the b-orientation growth of titanium silicalite zeolite membranes on 304 stainless steel substrate were systematically studied by classical in?situ hydrothermal crystallization method. The results show that the hydroxyl groups on the surface of TiO₂ interlayer can directionally induce the adsorption of zeolite grains， and then improve the b-orientation of the membrane. At the same time， the content of TPAOH and H₂O in the precursor solution has a significant effect on the grain size and the directional growth of the membrane， that is， the high b-oriented titanium silicalite zeolite membranes can be formed only under the appropriate alkalinity. The results of this study have a certain guiding effect on the in?situ adjustment of the orientation of the titanium silicalite zeolite membranes.



Polymer Chemistry

Synthesis and Properties of Soluble Transparent Polyimides Containing tert-Butyl and Isobutyl Groups

WANG Shoubai, WU Xiuming, WU Jinming, TANG Yanfeng, SHU Chen, ZHONG Min, HUANG Wei, YAN Deyue

2021, 42(9):  2944-2952.  doi:10.7503/cjcu20210327

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A novel diamine containing tert-butyl and isobutyl groups｛4，4′-（2-isobutyl）bis［2-（tert-butyl） aniline］， IBBTBA｝ was synthesized from 2-tert-butyl aniline and isobutyraldehyde. Then a series of polyimides（PIs） was prepared from IBBTBA and four aromatic dianhydrides by the high-temperature one-plot polymerization. The structure and properties of the PIs were investigated in detail. The results indicate that all PIs show good solubility not only in high-boiling aprotic solvents［N-methylpyrrolidone（NMP）， N，N-dimethylacetamide（DMAc）， etc.］， but also in low boiling point solvents［ethyl acetate（EA）， CHCl₃， etc.］. They can be processed into flexible films easily by the solution casting or blade coating. All the resulting PI films（around 25 μm in thickness） have good transparency with the average transmittance from 82.3% to 89.1% and the cut-off wavelength from 313 nm to 363 nm in the visible light region. Satisfactorily， all PIs still maintain the good thermal stability. Their 5% mass loss temperatures（in N₂） are above 480 ℃ and T_g values are in the range from 307 ℃ to 356 ℃. Besides， all PIs films exhibit good mechanical properties and hydrophobicity. In summary， these PI films are potential candidates for applications in the fields of photovoltaic power generation， flexible display and so on.



Effect of Flexibility of Composites on Performances of Sensors with Micro-structured Inverted Pyramid Arrays

ZHAO Lingyun, HUANG Hanxiong, LUO Duyu, SU Fengchun

2021, 42(9):  2953-2960.  doi:10.7503/cjcu20210281

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Two kinds of thermoplastic polyurethane/short carbon fiber/carbon nanotube（TPU/SCF-CNT） composites with different flexibilities were prepared by an extruder. By using compression molding， the replicas with micro-structured inverted pyramid arrays on the surfaces were molded from the two composites with the conductive paths comprised by SCF and CNT. Then two kinds of flexible sensors were prepared by assembling the composite replica with the corresponding composite flat plate face-to-face. It was demonstrated that the contact resistance between the replica and flat plates of the sensor under pressure was significantly reduced due to the deformation of the bottom edges of the inverted pyramid. Although the sensor assembled by using the more flexible composite had a slightly larger hysteresis coefficient， it exhibited a higher sensitivity（0.32 kPa^?1） in the linear region of 0—2.5 kPa， which is attributed to the larger deformation of the bottom edges of the inverted pyramid and the increased conductive paths inside the composite under pressure. Both sensors exhibited short response times stemming from rapidly changing contact resistance caused by the deformation of the bottom edges of the inverted pyramid. In addition， the sensors prepared in this work maintained a relatively stable resistance response during 500 s（approximately 1580 cycles） of cyclic compression/release tests（under a peak pressure of ca. 3 kPa）. The results demonstrated that it is feasible to fabricate higher performance flexible sensors with inverted pyramid arrays on the sensing element prepared by compression molding.



Synthesis of Poly（allyl glycidyl ether） Bearing Alkyl Functional Side Groups and Its Plasticizing and Antistatic Effects for PVC

ZHANG Wanbin, WANG Yanmeng, WANG Shaowu, TONG Xin, HAN Xiaoqian, ZHANG Ce, ZHANG Guanghua, ZHU Xiuzhong

2021, 42(9):  2961-2967.  doi:10.7503/cjcu20210278

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A novel alkyl functionalized polyether was synthesized by combination of anionic ring-opening polymerization（AROP） and thiol-ene click reaction. Afterwards， its plasticizing and antistatic effects for PVC were investigated. Firstly， poly（allyl glycidyl ether）（PAGE） intermediate product was obtained via AROP by using allyl glycidyl ether as a monomer and t-BuOK as an initiator. Then， PAGE was used as a precursor and flexible alkyl groups were introduced by employing thiol-ene click reaction， and PAGE_butane target product was obtained finally. Nuclear magnetic resonance（NMR） and gel permeation chromatography（GPC） measurements verified that the structure of resultant polymer was consistent with the design， and the molecular weight of PAGE can be flexibly tailored by varying the feed ratio of monomer to initiator. The studies on the thermal properties suggest that with the incorporation of alkyl groups， the glass transition temperature（T_g） decreased accordingly， and the T_g for PAGE_butane was -74.97 ℃. PAGE_butane exhibit good thermal stability. PAGE_butane could improve the toughness of PVC obviously without sacrificing its strength. Meanwhile， it could effectively reduce the surface resistivity of PVC and act as an antistatic agent. As compared to bis（2-ethylhexyl） phthalate（DOP）， PAGE_butane exhibited enhanced resistance to extraction and volatility.



Ring-opening Polymerization of Cyclic Esters Using Recyclable Polystyrene Supported Urea-Base Binary Catalyst

MA Yukun, JIN Hui, REN Chuanli, LI Zhibo

2021, 42(9):  2968-2973.  doi:10.7503/cjcu20210266

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To solve the catalyst residual problem， a promising strategy is to immobilize active catalyst on the surface of polymer microspheres to make heterogeneous catalyst. Herein， a metal-free approach to the ring-opening polymerization of lactones using recyclable polystyrene supported urea-potassium methoxide binary catalyst system is described. The new heterogeneous catalysts， polystyrene（PS）-supported cyclohexyl urea （PS-U₁） and polystyrene-supported 4-（trifluoromethye） phenyl urea（PS-U₂）， were prepared by reactions of amine-functionalized PS microspheres with cyclohexyl isocyanate and 4-（trifluoromethyl）phenyl isocyanate， respectively. It was found that PS-U-potassium methoxide catalytic system exhibited high catalytic activity for ring-opening polymerization（ROP） of lactones， including ε-caprolactone（ε-CL）， δ-valerolactone（δ-VL） and rac-lactide（rac-LA）. In addition， the heterogeneous PS-U could be easily separated via simple filtration and recycled. It is worth noting that the recycled PS-U catalyst could be reused without significant decrease of catalytic activity.



Copolymerization of Methyl Acrylate and 1-Octene Catalyzed by the Loaded Aluminum Chloride on MCM-41 Molecular Sieve

LI Haibo, XIAO Changfa, JIANG Long, HUANG Yun, DAN Yi

2021, 42(9):  2974-2981.  doi:10.7503/cjcu20210246

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The loaded aluminum chloride on MCM-41 molecular sieve was used to catalyze the copolymerization of methyl acrylate and 1-octene. Through detecting the polymer yield by weighing method， the copolymer composition by hydrogen nuclear magnetic resonance spectroscopy， and the relative number average molecular weight by gel permeation chromatography， the relationship of the polymer yield and copolymer composition with the polymerization reaction time， the influence of the catalyst composition and the amount of the catalyst on the copolymerization， as well as the catalyst recycling performance were studied. The results show that the polymer yield increases with time in an S-shape， while the composition of the copolymer almost remains constant with time， which is consistent with the law of the aluminum chloride catalyst system； the solvent（dichloromethane， ethanol or xylene） mainly affects the composition of the polymer， and has little effect on the relative number average molecular weight and distribution of the polymer； the increase of active components in the catalyst is beneficial to increase the 1-octene unit in the copolymer， but has little effect on the molecular weight and molecular weight distribution of the polymer； when the active component content in the catalyst is constant， the increase of the molar ratio of catalyst to monomer from 0.125 to 0.5 is beneficial for increasing the content of 1-octene units in the copolymer. After the catalyst is used for three times， it still has good cataly-tic activity， and the olefin unit can be introduced into the copolymer to obtain a poly（methyl acrylate-co-1-octene） copolymer with a 1-octene unit content of 30.1%.



Single-molecule Mechanics of Polyacrylamide Under Different Liquid Environments

CAO Meiqi, LIU Xia, CUI Shuxun

2021, 42(9):  2982-2988.  doi:10.7503/cjcu20210241

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The single-chain elasticity of nonionic polyacrylamide（NPAM） and its hydrolysate（anion polyacrylamide， APAM） in different liquid environments was investigated by single molecule force spectroscopy（SMFS） . The modified freely jointed chain（M-FJC） model was used to describe the single-chain elasticity of NPAM in aqueous solution at different pH values with a parameter of single-chain modulus（K₀）. The experimental results show that K₀ is increased with increasing the pH value of the aqueous solution. It is demonstra-ted that the hydrolysis degrees of NPAM in the alkaline solution are pH-dependent. Because K₀ has a positive correlation with the net charge of the polymer chain， the increased K₀ in high-pH solution indicates that the net charge of NPAM chain is increased， and the high electrostatic repulsion between structural units makes polymers present extended conformations. On this basis， the conformations of APAM in aqueous solution at diffe-rent pH values were studied. We find that APAM is flexible in acid solution and is more rigid in basic solution. The findings can be used to illustrate the swelling mechanism of the hydrogel network constructed by APAM chains at the molecular level.



Materials Chemistry

Preparation and Application of Triplethiophene Derivative Functionalized SiO₂ Inverse Opal Photonic Crystal Fluorescent Films

LI Ran, ZHANG Xudong, MU Lidan, SUN Tong, AI Ganggang, SHA Yelong, ZHANG Yuqi, WANG Jijiang

2021, 42(9):  2989-2995.  doi:10.7503/cjcu20210307

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The as-prepared SiO₂ inverse opal photonic crystal（IOPC） was sequentially treated with the mixture of concentrated sulfuric acid and hydrogen peroxide， toluene solution of 3-aminopropyl trimethoxy silane， chloroform solution of trithiophene derivative（denoted as 3T） and methanol solution of sodium borohydride to obtain a 3T-functionalized SiO₂ IOPC. The resulting photonic crystal（PC） film emits fluorescence at 512 nm and the fluorescence quenches at UV radiation. A new fluorescence emission can be observed at 458 nm when the IOPC film is subsequently exposed to formaldehyde atmosphere. The fluorescence can be observed in 20 s in formaldehyde vapor and will quench in air atmosphere. The IOPC film can maintain strong fluorescence after ten cycles when alternately exposed to formaldehyde vapor and air， showing a good repeatability. Taking trithiophene derivative smooth film without IOPC structure as a control sample， the fluorescence of 3T-functionalized IOPC films fabricated from polystyrene microspheres templates of 300 and 400 nm was enhanced by 47.5 and 78.6 times in formaldehyde vapor， respectively. This is because the fluorescence emission wavelength is overlapped with the red and blue band-edge of the PC’s photonic stopband， resulting in the slow photon effect and enhancing the fluorescence intensity remarkably. The fabricated 3T-funtionalized SiO₂ IOPC in this work provides a novel strategy for the preparation of photonic crystal fluore-scent film sensors.



Electrochromic Property of the WO₃/PANI Core-Shell Inverse Opal Structure Film

JIANG Liqi, WEI Ke, WANG Lang, XIAO Houdi, YANG Jiuxiang, HU Zhiyi, LIU Jing, LI Yu, LYU Mingyun, SU Baolian

2021, 42(9):  2996-3004.  doi:10.7503/cjcu20210131

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A conductive polymer polyaniline（PANI） layer was introduced on the surface of the inverse opal structure tungsten trioxide（IO-WO₃） film by the successive ionic layer adsorption and reaction， then a unique core-shell inverse opal structure WO₃/PANI（IO-WO₃/PANI） film was fabricated. The morphology， composition， and electrochemical behavior of the IO-WO₃/PANI film were studied and compared with the IO-WO₃ film. When the potential scan ranged from -0.6 V to 1.0 V， the IO-WO₃/PANI composite film showed different colors under different voltage states， namely blue（1.0 V）， green（0.2 V）， light green（0 V） and blue-violet （-0.6 V）. Compared with the IO-WO₃ film， the electrochromic performance of the IO-WO₃/PANI film is signi-ficantly improved. The coloring and fading response times are 3.8 and 6.14 s， respectively， and the color change efficiency（CE） value is 201.1 cm²/C. The improvement of electrochromic performance is mainly attri- buted to the formation of the donor-acceptor system and the hierarchically porous structure in the core-shell inverse opal， which enable rapid ion diffusion and provide a larger surface area for charge transfer reactions. The results show that the IO-WO₃/PANI core-shell inverse opal film is a potential multicolor electrochromic material and has broad application prospects in the future.