GaN/ZnO复合体的制备及光催化性能

首先用聚乙烯吡咯烷酮(PVP)作为表面活性剂, 硝酸镓[Ga(NO₃)₃]作为镓源, 采用溶胶-凝胶法制备了GaN粉末。然后通过固相法将GaN粉末和ZnO粉末按不同配比机械混合, 制备成GaN/ZnO复合体。采用X射线粉末衍射(XRD)、扫描电镜(SEM)、X射线能谱 (EDS)、高分辨透射电子显微镜(HRTEM)和发致光谱(PL)表征GaN/ZnO复合体的微结构、形貌、成分和发光特性, 并将其作为催化剂进行降解亚甲基蓝水溶液的光催化性能测试。结果表明: GaN/ZnO复合体对比未经复合的GaN和ZnO粉末, 光催化性能有明显的增强。基于一级动力学方程分析, 当GaN/ZnO复合体中GaN粉末和ZnO粉末含量配比为1: 2时, 光催化性能达到最佳, 其速率常数k值为0.11 min^-1。

Fabrication and Photocatalytic Performance of GaN/ZnO Composites

GaN powder was firstly synthesized by the Sol-Gel method using polyvinylpyrrolidone (PVP) and gallium nitrate [Ga(NO₃)₃] as surfactant and gallium source, respectively. Then, GaN/ZnO composites were prepared by solid phase method through mechanical mixing GaN powder and ZnO powder with different proportions. The composites were characterized by using X-Ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), high-resolution X-ray electron microscope (HRTEM) and photoluminescence (PL) spectra. The photocatalytic performance of GaN/ZnO composites as catalyst was tested by degradation of methylene blue in aqueous solution under white light irradiation. The results show that the photocatalytic property of GaN/ZnO composites is obviously improved comparing with that of pure GaN and ZnO powders. The photocatalytic activity is analyzed by pseudo-first-order kinetics equation, showing that the best photodegradation rate constant k is 0.11 min^-1 for the GaN/ZnO composites with GaN and ZnO mixing ratio of 1: 2.