Table of Content

10 February 2022, Volume 43 Issue 2

Previous Issue    Next Issue

Content

Cover and Content of Chemical Journal of Chinese Universities Vol.43 No.2(2022)

2022, 43(2):  1-6. 

Asbtract ( )   PDF (9437KB) ( )  

Related Articles | Metrics

Review

Recent Progress in Photoelectrochemical H₂ Production Coupled with Biomass-derived Alcohol/aldehyde Oxidation

CHEN Wangsong, LUO Lan, LIU Yuguang, ZHOU Hua, KONG Xianggui, LI Zhenhua, DUAN Haohong

2022, 43(2):  20210683.  doi:10.7503/cjcu20210683

Asbtract ( )   HTML ( )   PDF (2953KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Biomass-derived alcohol/aldehydes are important platform compounds， which can be further converted into high-value-added chemicals or fuels through catalytic oxidation. Photoelectrocatalytic（PEC） technology driven by solar energy is one of the most green and efficient ways to realize the oxidation of biomass-derived alcohol/aldehydes. Compared with the traditional PEC water splitting process to produce both O₂ and H₂， the use of PEC oxidation of biomass-derived alcohol/aldehydes instead of anodic oxygen evolution process can not only increase the value of anodic products， but also improve the conversion efficiency of solar energy to hydrogen， which is of great significance for H₂ production and high value chemical synthesis. In this review， we introduce the reaction mechanism of PEC H₂ production coupled with biomass-derived alcohol/aldehyde oxidation， and summarize the recent progress in PEC oxidation of biomass-derived alcohol/aldehydes. Moreover， the opportunities and challenges in this field are also prospected.



Article: Inorganic Chemistry

Preparation and in vitro Bioactivity of HA/CuO/SrCO₃ Gradiently Composite Coating

ZHAO Mengyang, HUANG Ziyang

2022, 43(2):  20210644.  doi:10.7503/cjcu20210644

Asbtract ( )   HTML ( )   PDF (6832KB) ( )  

Figures and Tables | References | Related Articles | Metrics

In hydroxyapatite（HA） suspension， n-butanol as dispersion medium， triethanolamine as emulsifier， two osteogenic trace element compounds CuO and SrCO₃ as additives， Ti sheet as substrate， chitosan（CS） as porogen， an HA/CS/CuO/SrCO₃ composite coating was obtained by zonal electrophoresis distribution and electrophoretic deposition under the action of reverse electric field. And then， an HA/CuO/SrCO₃ composite coating was prepared after high temperature calcination at 700 ℃ for 2 h. Some equipments and methods such as powder X-ray diffraction（XRD）， Fourier transform infrared spectroscopy（FTIR）， field emission scanning electron microscopy（FESEM）， energy dispersive spectroscopy（EDS）， Lloyd universal material testing machine， electrochemical workstation， culture in simulated body fluid and inhibition experiment， were used to test and characterize the composite coatings. The results show that all of the contents of Ca， Cu and Sr elements had presented a gradient distribution in the radial direction of the HA/CuO/SrCO₃ composite coating. The bonding strength between the composite coating and the Ti substrate was 33.0 MPa. The composite coating possessed stable electrochemical performance and strong corrosion resistance in （N-（2-hydroxyethyl）piperazine）-N'-2-ethane sulfonic acid（HEPES） simulated body fluids（H-SBF） under tested by cyclic voltammetry（CV） curves and Tafel polarization curves. The surface of the composite coating was apatite-carbonated completely after cultured in H-SBF for 24 d. The inhibition rates of the composite coating powder against Escherichia coli and Staphylococcus aureus were 81.82% and 71.86%， respectively.



A Squaramide-containing Luminescent Metal-organic Framework as a High Selective Sensor for Histidine

TIAN Xueqin, MO Zheng, DING Xin, WU Pengyan, WANG Yu, WANG Jian

2022, 43(2):  20210589.  doi:10.7503/cjcu20210589

Asbtract ( )   HTML ( )   PDF (3909KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A novel squaramide-containing metal-organic framework（Co-L） has been prepared by solvothermal reaction of 5，5′-［（3，4-dioxocyclobut-1-ene-1，2-diyl）bis（azanediyl）］diisophthalic acid and cobalt nitrate hexahydrate in alkaline water. X-Ray single crystal diffraction result shows that Co-L is a three-dimensional framework structure formed by one-dimensional chains through hydrogen bonding and CH…π interaction and has 1D channels with the window diameters cross section of 0.52 and 0.63 nm along b and c directions， respectively. Fluorescence tests displayed that Co-L could detect histidine among 20 natural amino acids with high selectivity， and the detection mechanism was also studied.



Organic Chemistry

Catalyst-free and Highly Efficient O-Silylation of Alcohols and Phenols

YU Jing, WU Chao, LI Chenyang, CHEN Danfeng, DING Liuyue, MA Xiantao

2022, 43(2):  20210588.  doi:10.7503/cjcu20210588

Asbtract ( )   HTML ( )   PDF (797KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

Silyl ethers are widely used in many fields such as organic synthesis， separation analysis， fine chemicals， etc. Hexamethyldiazosilane（HMDS） was recently developed as a new silyl reagent for the efficient synthesis of silyl ethers. However， a catalyst was usually required to activate the inert HMDS. In this work， an efficient and catalyst-free O-Silylation of alcohols and phenols was developed. This new method could be successfully applied to a variety of primary benzyl alcohols， heteroaryl benzyl alcohols， aliphatic alcohols， secondary alcohols and even tertiary alcohols. In Most cases， the target product was obtained under column chromatography-free conditions with a quantitative isolated yield. This method can be extended to the highly efficient O-Silylation of phenols， and also be easily scaled up to 100 mmol， giving the target product in 99% isolated yield， indicating that this new method is of good practical value.



Synthesis and Characterization of Antihypertensive Drug Aranidipine and Its Related Impurities

LI Jing, SU Wei, WANG Xueyuan, FU Peng, SUN Yan

2022, 43(2):  20210663.  doi:10.7503/cjcu20210663

Asbtract ( )   HTML ( )   PDF (897KB) ( )  

Figures and Tables | References | Related Articles | Metrics

In this paper， a high-yield synthetic scheme of aranidipine was created. The optimization conditions of the new synthetic method were discussed， and the overall yield increased by 20%. Through the structural characteristics and synthetic process， six kinds of Aranidipine impurities were found， whose preparation methods and characte-rization were provided in the meantime. Moreover， the high performance liquid chromatography（HPLC） method was established for the determination of related impurities in Aranidipine， and was able to supply an experimental basis for the formulation of its quality standard.



Polymer Chemistry

Synthesis of A Novel Photoluminescence Self-healing Hydrogel

ZHOU Yonghui, LI Yao, WU Yuxuan, TIAN Jing, XU Longquan, FEI Xu

2022, 43(2):  20210606.  doi:10.7503/cjcu20210606

Asbtract ( )   HTML ( )   PDF (10773KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

Self-healing hydrogels with photoluminescence properties were prepared by free radical polymerization， which solved the fluorescence quenching problem of photoluminescence complexes in water phase. The oil-soluble Eu-containing rare earth complex is introduced into the hydrogel system by designing a covalent bond， and the complex is stable and non-diffusion in the hydrogel system. The Eu-containing rare earth complex has the characteristics of ultraviolet photoluminescence， which endows the hydrogel with good recognizability. At the same time， the hydrogel contains dynamic borate ester bonds， and its fast-healing properties enable the hydrogel to repair the damage in a short time when it is damaged， which provides a new idea for the preparation of luminescent hydrogel and identifiable biomedical materials.



Synthesis and Coating Properties of Carboxylated Fluorinated Poly（arylene ether）s

ZHANG Wenmeng, LI Mengqin, HOU Zhen, CHEN Dongyang

2022, 43(2):  20210604.  doi:10.7503/cjcu20210604

Asbtract ( )   HTML ( )   PDF (10717KB) ( )  

Figures and Tables | References | Related Articles | Metrics

In order to improve the adhesion of aromatic fluorocarbon coatings， tetraallyl biphenyl diphenol（TABP）， bisphenol A and decafluorobiphenyl were used as starting materials to prepare fluorinated poly（arylene ether）s（FPAEs） through room temperature polycondensation. After that， 3-mercaptopropionic acid was grafted to achieve carboxylated fluorinated poly（arylene ether）s（CFPAEs）. The carboxyl content of the products was adjusted by changing the loading amount of TABP. The CFPAE coatings were prepared by spraying the polymer solutions in 1-methyl-2-pyrrolidinone（NMP） onto tinplate. It has been found that the CFPAE coatings have excellent thermal stability and mechanical strength. The introduction of carboxyl groups could significantly improve the adhesion of the fluorocarbon coating. When the carboxyl content is 0.265 mmol/g， the adhesion level of the coating is 0， the pencil hardness is 6H， the minimum shaft rod diameter without coating damage is 0.5 mm， and the water contact angle is 103.9°. In addition， the CFPAE coatings also have excellent acid resistance， salt resistance， anti-ultraviolet aging and anti-corrosion properties. Therefore， the carboxylation is an effective way to expand the application of fluorinated poly（arylene ether）s to aromatic fluorocarbon coatings.



Self-Assembly of Graphene Oxide at Poly（3-hydroxybutyrate） Microparticles Toward High-performance Intercalated Nanocomposites

ZHANG Zhibo, SHANG Han, XU Wenxuan, HAN Guangdong, CUI Jinsheng, YANG Haoran, LI Ruixin, ZHANG Shenghui, XU Huan

2022, 43(2):  20210566.  doi:10.7503/cjcu20210566

Asbtract ( )   HTML ( )   PDF (22914KB) ( )  

Figures and Tables | References | Related Articles | Metrics

As one of the most important natural biopolymers， poly（3-hydroxybutyrate）（PHB） has been identified by an ecofriendly lifecycle from bacterial synthesis to practical processing and recycling， holding great promise in applications for biomedical and packaging materials. However， due to the intrinsic characters including poor self- nucleation capability and excessively large spherulites， the application of PHB is dwarfed by low impact resistance， poor ductility and high creep compliance. Herein， a combination of aqueous processing and confined structuring was proposed to prepare graphene oxide（GO）-intercalated PHB nanocomposites. In specific， GO nanosheets were exfo- liated and dispersed in water， which would encapsulate the submicron PHB microspheres to form the PHB@GO self-assemblies， followed by confined structuring under a high pressure above the melting temperature of PHB. Albeit at an ultralow loading of 0.1%（mass fraction）， the intercalated GO nanosheets showed high capability to enhanced the isothermal and non-isothermal crystallization kinetics of PHB， resulting in highly dense spherulites with a relatively uniform size. An unexcepted brittle-ductile transition was developed in the intercalated nanocomposites， leading to remarkable increase in tensile strength and elongation at break. This was accompanied by significant rise of thermomechanical properties and creep resistance， especially at high temperatures. The flexibility in the choice of functional nanofillers permits broad applications in the fabrication of high-performance PHB-based composites.



Physical Chemistry

Optimal Distribution of Active Sites of CO₂ Reduction Reaction Catalyzed by Diatomic Site M-N-C

ZHOU Ying, HE Peinan, FENG Haisong, ZHANG Xin

2022, 43(2):  20210640.  doi:10.7503/cjcu20210640

Asbtract ( )   HTML ( )   PDF (949KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

The diatomic site M-N-C catalysts are one of the best catalysts for CO₂ reduction reaction（CO₂RR）. However， the current researches mainly focus on the regulation of the atom type of the active center of M-N-C， and underestimate the effect of the coordination environment and distribution of the active sites on their catalytic performance. A typical diatomic site M-N-C catalyst（NiFe-N-C） was selected as the research object， and the electrocatalytic CO₂RR reaction mechanism of nine types of NiFe-N-C catalysts with different coordination environments at active sites were systematically investigated by the density functional theory（DFT） method. The results show that with the increase of the coordination number of metal atoms and the distance between diatomic sites， the stability of M-N-C catalysts， the catalytic activity of CO₂ reduction to CO， and the selectivity of inhibiting hydrogen evolution reaction all show a trend of increasing first and then decreasing. Among them， the NiFe-N-C-model 3 catalyst with four-coordinated and symmetrically distributed metal atoms exhibits the best catalytic performance due to the strong interaction of the diatomic sites. This study provides theoretical support for the precise regulation of active sites in diatomic site M-N-C catalysts and the rational design of CO₂RR catalysts.



Mechanism and Kinetics on the Reaction of Isopropyl Nitrate with Cl， OH and NO₃ Radicals

SUN Cuihong, LYU Liqiang, LIU Ying, WANG Yan, YANG Jing, ZHANG Shaowen

2022, 43(2):  20210591.  doi:10.7503/cjcu20210591

Asbtract ( )   HTML ( )   PDF (2000KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

The reaction mechanism of （CH₃）₂CHONO₂ with X（X=Cl， OH and NO₃ radical） was studied at M06-2X/ 6-311++G（d，p） level of theory， and the energy of the stationary points was calculated by CCSD（T） method. The kinetics of the reaction was calculated by the conventional transition state theory. The hydrogen bonded complexes are formed firstly by isopropyl nitrate and X radical， and X radical can abstract the α-H or β-H atoms from （CH₃）₂CHONO₂. The α-H abstraction is the main channel， and the main products are （CH₃）₂CO + NO₂ + HCl（H₂O or HNO₃）. The yield of α-H abstraction products decreases as the temperature increases from 200 K to 500 K for IPN + OH reaction. The overall rate constant for the reaction of （CH₃）₂CHONO₂ with Cl atom， OH and NO₃ radical at 300 K is 3.933×10^-11， 1.182×10^-13， and 7.134×10^-19 cm³·molecule^-1·s^-1， respectively. The theoretical kinetics data is in consistent with the previous experimental values for the reaction of OH with isopropyl nitrate.



Rate Rules for Hydrogen Abstraction Reactions of Polycyclic Aromatic Hydrocarbons and Unsaturated Radicals

DENG Hongri, CAO Xiaomei, WANG Jingbo, LI Xiangyuan

2022, 43(2):  20210563.  doi:10.7503/cjcu20210563

Asbtract ( )   HTML ( )   PDF (961KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

The reaction kinetics for a series of polycyclic aromatic hydrocarbons（PAHs） containing up to six aroma-tic rings by propynyl radical（C₃H₃）， allyl radical（C₃H₅）， butadienyl radical（nC₄H₅， iC₄H₅）， pentadienyl radical （C₅H₅） and phenyl radical（C₆H₅） were systematically investigated via the M06-2X/cc-pVTZ method. Based on the electronic structure calculations， the rate constants of title reactions were calculated by using transition state theory coupled with Eckart tunneling correction at the temperature range of 500—2500 K. The effects of PAH sizes and structures on the rate constants were examined. The results show that the PAH sizes have little effect on the rate constants， while the structures of PAHs influence the rate constant significantly. Hence， the hydrogen abstraction reactions are simplified into C₅ and C₆ reaction classes depending on the abstraction site on the five-membered or six-membered ring. The simple two classes are conducive to construct the combustion model of PAHs. The results indicate that C₆ class possesses a higher activity than the C₅ class. Hydrogen extraction reactions classes from PAHs by nC₄H₅， iC₄H₅ and C₆H₅ radicals are studied in a systematic way， and the reactivity of different H-abstraction reactions from PAHs by different radicals shows the following trends： C₆H₅>nC₄H₅>iC₄H₅. The rate rules are summarized by taking the average values of rate constants of a representative set of reactions in each class， which are applicable for the chemical model construction of PAHs.



Preparation， Characterization and Degradation to BPA of Pomegranate-like Gel Microsphere Entrapmented Laccase

ZHOU Ning, TANG Xiaohua, CAO Hong, ZHA Fei, LI Chun, XIE Chunyan, XU Mingping, SUN Yige

2022, 43(2):  20210705.  doi:10.7503/cjcu20210705

Asbtract ( )   HTML ( )   PDF (6217KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The pomegranate-like gel microsphere Alg@Cu₃/Zn₃（PO₄）₂@Lac was prepared by double embedding laccase in copper/zinc composite metal phosphate crystals and calcium alginate gel. Characterized by SEM， EDX and FTIR， the laccase was successfully embedded in copper/zinc composite metal phosphate crystals coated by calcium alginate. And the copper/zinc composite metal phosphate crystals were entrapped in the mesh pores of the calcium alginate gel like pomegranate-shaped. Enzymatic properties with ABTS as a substrate show that the heat resistance， acid resistance and storage stability of Alg@Cu₃/Zn₃（PO₄）₂@Lac are enhanced under the double protection of inorga-nic salt crystals and calcium alginate gel compared to free laccase. Alg@Cu₃/Zn₃（PO₄）₂@Lac was applied to the degradation of bisphenol A（BPA）， and an aperture diameter of approximately 1 mm filter was used to achieve rapid recovery. The degradation rate of BPA decreased by only about 14% after six cycles， showing relatively stable reavailability， mainly due to the dual protection of calcium alginate and copper/zinc inorganic salt crystals. This paper provides the method and basis for establishing a new immobilization technology to enzyme.



Organocatalyzed Asymmetric Friedel-Crafts Alkylation in the Carbocyclic Ring of Indole

MU Hongwen, WU Hao, GAO Yingying, JIN Ying, WANG Liming

2022, 43(2):  20210571.  doi:10.7503/cjcu20210571

Asbtract ( )   HTML ( )   PDF (847KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

The indole scaffolds are privileged skeletons widely found in many bioactive natural products， pharmaceuticals， and material molecules. Indoles show a high nucleophilic reactivity in the azole ring， which preferentially reacts with electrophilic aromatic substitution at the C3 position. However， the methods for the enantioselective functionalization of the indole benzene ring are scarce. When hydroxylindoles as nucleophiles have been used in the Friedel-Crafts reaction， the regioselective hydroxyalkylation happens in the indole carbocyclic ring due to the advantage of the directing and activating properties of the OH group. Furthermore， the four regioisomeric hydroxylindoles lead to functionalize regioselective every position of the indole benzene ring. In this paper， Cinchona alkaloid derivatives were used to organocatalyze the enantioselective Friedel-Crafts reaction of hydroxylindoles with isatins. The effect of solvent， temperature and catalyst loading were investigated. The optimized conditions were determined to be tetrahydrofuran（THF） as the solvent with a 5%（molar fraction） loading of catalyst 1b at 0 ℃. The four regioisomeric hydroxylindoles（4-OH， 5-OH， 6-OH and 7-OH indoles） and the different substituted isatins were evaluated to explore the scope and general applicability of this reaction. The resulting products were obtained in good yields （67%—91%） with up to 97% e.e. and excellent regioselectivities（>15∶1）. The enantioselectivities were obviously affected by the position of hydroxyl group. When 4-OH indoles as nucleophiles reacted with 12 isatins， the main C5 substituted products were achieved with moderate to excellent stereoselectivities. The most reaction of 5-OH indoles got the main product of C4 position substitution with more than 80% e.e.. When 6-OH and 7-OH indoles reacted with isatins， the excellent regioselectivities were observed. Only C5 substituted products with 88%—93% e.e. were obtained in the reaction of 6-OH indoles， and only C6 substituted products with middle enantioselectivities （72%—78%）were achieved with 7-OH indoles as nucleophiles. The catalyst type and the substrate scope were broadened in this methodology.



Hot-pressed PVDF-based Difunctional Protective Layer for Lithium Metal Anodes

LI Weihui, LI Haobo, ZENG Cheng, LIANG Haoyue, CHEN Jiajun, LI Junyong, LI Huiqiao

2022, 43(2):  20210629.  doi:10.7503/cjcu20210629

Asbtract ( )   HTML ( )   PDF (5626KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

Lithium metal has been considered a promising anode for next-generation batteries due to its high specific energy（3860 mA·h/g） and lowest redox potential（-3.04 V vs. SHE）. However， the poor electrochemical stability of lithium metal results in limited cycle life and short-circuit due to lithium dendritic growth. Poor environmental stability of lithium metal also increases production difficulty and cost. Improving the interface stability of lithium metal anode is considered as an important approach to optimize battery performance. Herein， a dual-functional polyvinylidene fluoride（PVDF） protective layer is fabricated on lithium anode surface using a simple hot-pressing method， effectively promoting air stability to 120 min and increasing cycle life of the symmetrical battery to 1200 h. In addition， by introducing SnO₂ nanoparticles， an inorganic-organic composite protective layer is constructed. The composite protective layer induces lithium nucleation sites by in?situ alloying， which greatly reduces lithium plating overpotential to 0.007 V and facilitates better cyclability of lithium metal anodes. The full-cell with this protective layer shows a long cycle life of 200 cycles with a capacity retention rate higher than 90% and a high discharge capacity of 127 mA·h/g at a current rate of 3C. The strategy proposed in this work for the dual-function interface protective layer can effectively improve the air stability and electrochemical performance of lithium metal anode.



Graphene Oxide-based Cobalt Porphyrin Composites for Electrocatalytic Hydrogen Evolution Reaction

YU Bin, CHEN Xiaoyan, ZHAO Yue, CHEN Weichang, XIAO Xinyan, LIU Haiyang

2022, 43(2):  20210549.  doi:10.7503/cjcu20210549

Asbtract ( )   HTML ( )   PDF (4171KB) ( )  

Figures and Tables | References | Related Articles | Metrics

5，10，15，20-tetraphenyl porphyrin cobalt complex（CoTPP） was synthesized and used to prepare metalloporphyrin graphene oxide（GO） composite for electrocatalytic hydrogen evolutionreaction（HER）. The results indica-ted that when the mass ratio of CoTPP to GO is 1∶15， the performance of the composite is the best. The test of Raman and SEM revealed that the surface disorder of CoTPP/GO material was increased as compared to GO. This change is beneficial for the charge transfer of the HER. EIS test results showed the resistance of GO was reduced from 1180 Ω to 734 Ω of CoTPP/GO. The HER onset overpotential of material was reduced from -761 mV of GO to -337 mV of CoTPP/GO. Tafel slope was reduced from 296 mV/dec of GO to 174 mV/dec of CoTPP/GO， while the Faraday efficiency was increased from 23% to 87%. After adding diphenyl sulfide（SPh₂） axial ligand， the HER onset overpotential of CoTPP（SPh₂）/GO material was further reduced to -235 mV. Tafel slope was also reduced to 163 mV/dec and Faraday efficiency was increased to 94%. These results indicate that the self-assembly of graphene oxide and metalloporphyrin is an effective way to construct graphene-based metalloporphyrin electrocatalytic HER materials.



Effects of SmPO₄ Coatingon Electrochemical Performance of High-voltage LiNi_0.5Mn_1.5O₄ Cathode Materials

LI Xiaohui, WEI Aijia, MU Jinping, HE Rui, ZHANG Lihui, WANG Jun, LIU Zhenfa

2022, 43(2):  20210546.  doi:10.7503/cjcu20210546

Asbtract ( )   HTML ( )   PDF (7287KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Spinel-type LiNi_0.5Mn_1.5O₄ has been widely used in large-scale energy storage equipment， energy conversion equipment and power vehicle， due to its low preparation cost， high discharge platform and long cycle life. However， the electrolyte of LiNi_0.5Mn_1.5O₄ decomposes easily under high voltage（5 V） charging， which leads to a decrease in specific capacity and a decline in cycling performance. To solve the above problems， the LiNi_0.5Mn_1.5O₄ cathode material was successfully coated with a thin layer of SmPO₄via a hydrothermal process. The influence of the coating amount of SmPO₄ on the electrochemical performance of LiNi_0.5Mn_1.5O₄ material was systematically studied. The results indicate that the as-prepared LiNi_0.5Mn_1.5O₄ coated with 0.5%（mass fraction） SmPO₄（LNMO@SP-0.5） exhibits optimal electrochemical performance. In case of 0.2C and 5C， the discharge specific capacity of LNMO@SP-0.5 was 129.2^{and 90.9 mA?h/g， respectively， while Pristine LNMO only had 114.2 and 77.7 mA?h/g. LNMO@SP-0.5 exhibited a capacity retention of 93.4% after 500 cycles at 5C and 25 ℃， whereas the Pristine LNMO exhibited a poor capacity retention of 86.6%. The improvement was due to SmPO₄ coating can effectively alleviate the side reaction between LiNi_0.5Mn_1.5O₄ material and electrolyte， and reduce the polarization degree and charge transfer resistance of the electrode， and increase the diffusion coefficient of Li+.}



Dielectric Constant of Confined Water in a Bilayer Graphene Oxide Nanosystem

HU Bo, ZHU Haochen

2022, 43(2):  20210614.  doi:10.7503/cjcu20210614

Asbtract ( )   HTML ( )   PDF (3843KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The properties of the dielectric constant of water in confined systems vary greatly， which has a significant impact on its applications in electrochemistry， membrane treatment and energy storage. For example， in graphene pores， the physical properties are affected by factors such as membrane pore size and degree of oxidation， but few studies have been conducted in this regard. Therefore， in order to further understand the influence of pore size and oxidation degree on the dielectric properties， molecular dynamics simulation method was used to explore the dielectric behavior of water in the double-layer graphene nanochannels with different pore size and oxidation degree. At the same time， as a local diagonal tensor in a constrained system， the dielectric constant can be defined in two directions parallel to and orthogonal to the wall. The experimental results show that water molecules exhibit a greater spatial and orientation order in a narrow environment， and the dielectric constant of confined water decreases with the decrease of the space of the nanochannels. With the increase of oxidation degree， the influence of the wider spacing on the dielectric constant is greater than that of the narrower nanochannel. For the widest channels（d=1.2 nm）， the dielectric constant of the graphene bilayer decreased with the increase of oxidation degree， while for the relatively narrow channels（d=0.6 nm， 0.9 nm）， the dielectric behavior showed a non-monotonic trend. To understand the physics behind this， we calculated the number of hydrogen bonds in the three nanochannels. The results showed that the number of hydrogen bonds and the dynamic stability（corresponding to the fastest decay rate） were the lowest at 1.2 nm， indica?ting that the water molecules were more unstable and disordered in the large nanoscale than in the 0.6 nm and 0.9 nm nanoscale. This work emphasizes the significant importance of regulating the interlamellar distance for understanding the permeance of water and its transport mechanism and provides fundamental theories for the preparation of advanced materials based on graphene oxide（GO） and their application in water treatment.



New Mg-Al Type Sorbent for Efficient Removal of Boron from Waste Water Containing High-concentration of Boron from Pressurized Water Reactor Nuclear Power Plants

JIN Keyan, BAI Pu, LI Xiaolong, ZHANG Jianan, YAN Wenfu

2022, 43(2):  20210516.  doi:10.7503/cjcu20210516

Asbtract ( )   HTML ( )   PDF (2959KB) ( )  

Figures and Tables | References | Related Articles | Metrics

A new Mg-Al type layered double hydroxide（LDH） free of CO₃^2- was formed via a specific process consis-ting of the steps of first calcination and subsequent hydrolyzation in water of LDH source material. The resultant Mg-Al LDH can efficiently remove boron from simulated waste water containing high-concentration of boron from pressurized water reactor nuclear power plants. The concentration of boron in the simulated boron-containing waste water was reduced from 2000 mg/L to 10 mg/L by three cycles-relay treatment using the sorbent developed here， which met the requirement that the concentration of boron in the waste water has to be less than 30 mg/L for the construction of new inland nuclear power plants. The maximum sorption capacity of the sorbent developed in this study was as high as 39.64 mg/g at pH of 10.61 and temperature of 20 ℃. Meanwhile， the structural evolution at molecular level during the calcination and hydrolyzation process was investigated. The influence of parameters such as pH value， initial boron concentration， sorbent dosage， and agitation time on boron removal was also investigated.



Analytical Chemistry

Preparation， Characterization of Partially Reduced Graphene Oxide and Its Killing Effect on Human Cervical Cancer Cells

WANG Xueli, SONG Xiangwei, XIE Yanning, DU Niyang, WANG Zhenxin

2022, 43(2):  20210595.  doi:10.7503/cjcu20210595

Asbtract ( )   HTML ( )   PDF (8014KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Partially reduced grphene oxides（pRGO₁—pRGO₃， pRGO_1—3） were synthesized using a mild reduction method by incubating GO suspension under alkaline condition at room tempeature. Structure and morphology of the as-synthesized pRGO_1—3 nanocomposites were confirmed by means of FTIR， Raman， XPS， UV-Vis， transmission electron microscopy（TEM） and energy dispersive spectrometer（EDS）．pRGO possesses synergistic photodynamic and photothermal effects on tumor cell upon near-infrared（NIR） light irradiation. Consequently， pRGO can be expected to be a new nano carrier for tumor photodynamic and photothermal therapy.



Synthesis and Application of Quinolinone-coumarin-based Colorimetric Fluorescent Probe for Recognition of Hg²⁺

TANG Qian, DAN Feijun, GUO Tao, LAN Haichuang

2022, 43(2):  20210660.  doi:10.7503/cjcu20210660

Asbtract ( )   HTML ( )   PDF (2248KB) ( )  

Figures and Tables | References | Supplementary Material | Related Articles | Metrics

A novel quinolinone-coumarin probe， 7-diethylamino-3-［3-（7-diethylamino） coumarinyl-3-oxopropenyl］ quinolin-2-one（QCO）， was designed and synthesized for the detection of Hg²⁺ in an aqueous solution. QCO exhibited high selectivity and strong anti-interference for Hg²⁺. In addition， Hg²⁺ caused significant color changes of QCO solution， which could be identified with the naked eye. In the colorimetric method， the absorbance ratio A₅₀₀/A₃₈₀ had a good linear relationship with the Hg²⁺ concentration， and its detection limit was 2.62×10^-8 mol/L. In the fluorescence method， the detection limit of probe QCO for Hg²⁺ was 5.42×10^-8 mol/L. The stoichiometry of 1∶1（molar ratio） between QCO and Hg²⁺ was verified by Job's plot， MS and IR methods. Most remarkably， QCO could be used to detect Hg²⁺ in practical application by silicone board experiments and the standard recovery tests.



Material Chemistry

Preparation and Properties of Cu Particles Loaded Foam-based Phase Change Composites

CHU Yao, WANG Shuo, ZHANG Zinuo, WANG Yibo, CAI Yibing

2022, 43(2):  20210619.  doi:10.7503/cjcu20210619

Asbtract ( )   HTML ( )   PDF (5008KB) ( )  

Figures and Tables | References | Related Articles | Metrics

The carbon foam（CF） was made from melamine foam（MF） through high temperature carbonization， and was utilized as supporting matrix. The copper particles were deposited on the foam skeleton by redox reaction with copper chloride（CuCl₂） and hydrazine hydrate（N₂H₄·H₂O） as precursors. Subsequently， polyethylene glycol（PEG） was encapsulated into the matrix to fabricate phase change composites by vacuum impregnation method. The structural morphology and thermal properties of the fabricated phase change composites were studied by scanning electron microscopy（SEM）， X-ray diffraction（XRD）， differential scanning calorimetry（DSC） and Infrared thermal imager. The results showed that the Cu particles were uniformly and densely deposited on the skeleton surface of CF when the concentration of CuCl₂ solution was 1.0 mol/L. The fabricated phase change composite demonstrated good leakage-proof property， the phase change latent heat was as high as 145.2 J/g， the thermal efficiency was higher than 80%， and the photo-thermal conversion efficiency reached up to 83.8 %， which exhibiting excellent heat storage capacity and temperature regulation performance. This paper provides a strategy for the fabrication of phase change composites with excellent comprehensive performances， which is conducive to broaden its applications.



Preparation of High Thermal Conductivity Phase Change Monolithic Materials Based on Pickering Emulsion Stabilized by Surface Modified Graphene Oxide

YANG Junge, GAO Chengqian, LI Boxin, YIN Dezhong

2022, 43(2):  20210593.  doi:10.7503/cjcu20210593

Asbtract ( )   HTML ( )   PDF (6948KB) ( )  

Figures and Tables | References | Related Articles | Metrics

Filling with nano-materials is a common method to improve the thermal conductivity of phase change composites， and the dispersibility of nanomaterials is a key factor in enhancing thermal conductivity. In this paper， surface-initiated atom transfer radical polymerization（SI-ATRP） was used to modify grapheme oxide（GO） firstly， and then the modified GO was employed to stabilize Pickering high internal phase emulsion. Finally GO/paraffin monolith with high thermal conductivity was obtained by one step polymerization. SI-ATRP introduced molecular brushes on GO to improve the dispersion of GO， which endowed the monolith with excellent heat conduction enhancement effect， even under low GO content. When the content of GO was only 0.4% of the composite material， its thermal conductivity（3.968 W?m^-1?K^-1） was greatly improved compared to the thermal conductivity of pure paraffin（0.608 W?m^-1?K^-1）. The leakage rate of phase change material was only 1.1%—1.3% after 1000 cycles， showing good shape stability and thermal reliability. The prepared shape-stable phase change material has potential applications in temperature control and energy storage applications.