高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (10): 2178-2185.doi: 10.7503/cjcu20190215

• 物理化学 • 上一篇    下一篇

质子化g-C3N4/β-SiC复合材料的制备及光催化降解茜素红性能

吴之强,刘万毅(),王刚,蔡威,岳晓菲,詹海鹃(),毕淑娴,孟哲,马保军   

  1. 宁夏大学化学化工学院, 省部共建煤炭高效利用与绿色化工国家重点实验室, 化学国家级实验教学示范中心, 银川 750021
  • 收稿日期:2019-04-12 出版日期:2019-10-10 发布日期:2019-10-16
  • 通讯作者: 刘万毅,詹海鹃 E-mail:liuwy@nxu.edu.cn;zhanhj@nxu.edu.cn
  • 基金资助:
    宁夏国内一流学科建设项目(No.NXYLXK2017A04);西部地区建设“一流大学”重大创新项目(No.ZKZD2017003);国家自然科学基金(No.21862013)

Preparation of Protonated g-C3N4/β-SiC Composites and Photocatalytic Degradation of Alizarin Red S

WU Zhiqiang,LIU Wanyi(),WANG Gang,CAI Wei,YUE Xiaofei,ZHAN Haijuan(),BI Shuxian,MENG Zhe,MA Baojun   

  1. State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, National Demonstration Center for Experimental Chemistry Education, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
  • Received:2019-04-12 Online:2019-10-10 Published:2019-10-16
  • Contact: LIU Wanyi,ZHAN Haijuan E-mail:liuwy@nxu.edu.cn;zhanhj@nxu.edu.cn
  • Supported by:
    † Supported by the National First-Rate Discipline Construction of Ningxia, China(No.NXYLXK2017A04);the Major Innovation Projects for Building First-class Universities in China’s Western Region(No.ZKZD2017003);the National Natural Science Foundation of China.(No.21862013)

摘要:

分别采用热解法和溶胶-凝胶-碳热还原法合成了石墨相氮化碳(g-C3N4)和纳米级碳化硅(β-SiC), 通过浸渍-热处理法将两者复合并通过浓盐酸质子化, 分别制备了g-C3N4/β-SiC和质子化g-C3N4/β-SiC(P-g-C3N4/β-SiC)复合光催化剂. 利用X射线衍射(XRD)、 扫描电子显微镜(SEM)、 高分辨透射电子显微镜(HRTEM)、 傅里叶变换红外光谱(FTIR)、 X射线光电子能谱(XPS)、 紫外-可见漫反射光谱(UV-Vis-DRS)和光致发光光谱(PL)等对样品进行了表征. 结果表明, P-g-C3N4/β-SiC复合材料的比表面积增大, 光生电子-空穴对的复合几率降低, 光催化性能明显提高. 在光催化降解染料茜素红(ARS)研究中, 样品的可见光催化活性顺序为P-g-C3N4/β-SiC>g-C3N4/β-SiC>P-g-C3N4>g-C3N4>β-SiC. 其中P-g-C3N4/β-SiC在60 min内对ARS的降解效率高达99.9%, 符合准一阶动力学模型, 速率常数为0.0967 min -1, 且循环使用9次后, 光催化降解效率仍保持97.5%以上.

关键词: g-C3N4/β-SiC, 质子化, 光催化降解, 高效循环, 茜素红

Abstract:

Graphite phase carbonitride(g-C3N4) and silicon carbide(β-SiC) were synthesized by pyrolysis and sol-gel-carbothermic reduction method, respectively. Then, they were combined by the impregnation-heat treatment and protonated by concentrated hydrochloric acid to prepare g-C3N4/β-SiC and protonated g-C3N4/β-SiC(P-g-C3N4/β-SiC) composite photocatalysts. The samples were analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM), high resolution transmission electron microscopy(HRTEM), Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), UV-Vis diffuse reflectance spectroscopy(UV-Vis-DRS) and phototluminescence(PL) characterization. The results show that the P-g-C3N4/β-SiC composite did not retain the lamellar morphology and its specific surface area is significantly increased. The UV-Vis-DRS and PL spectra indicate that the recombination probability of photogenerated electron-hole pairs is significantly reduced, and the band gap is significantly improved. At the same time, experiments revealed that the combination of g-C3N4 and β-SiC and protonation can have a positive effect on the effective separation of photogenerated electron-hole pairs. In addition, the catalysts were applied to photocataly-tic degradation of alizarin red S(ARS). The results show that the order of visible light photocatalytic activity of the samples is P-g-C3N4/β-SiC>g-C3N4/β-SiC>P-g-C3N4>g-C3N4>β-SiC. The degradation efficiency of sample P-g-C3N4/β-SiC to ARS was up to 99.9% within 60 min, which accorded with the pseudo first-order kinetic model. The rate constant was 0.0967 min -1. After 9 times of cycle, the photocatalytic degradation efficiency of P-g-C3N4/β-SiC for ARS remained above 97.5%.

Key words: g-C3N4/β-SiC, Protonation, Photocatalytic degradation, High efficiency cycle, Alizarin red S

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