ZnO/In2O3复合空心球的制备及其光电催化葡萄糖降解性能

通过葡萄糖协助的水热以及随后的退火处理两步法成功制备了系列ZnO/In₂O₃复合空心球. X射线衍射谱(XRD)表明, 经500 ℃退火制得的ZnO/In₂O₃复合空心球中ZnO以非晶态存在, 但是随着退火温度的提高, 其逐渐转变为纤锌矿结构. 场发射扫描电子显微镜(FE-SEM)和透射显微镜(TEM)结果表明, ZnO/In₂O₃复合材料具有空心球结构, 复合纳米颗粒之间结合紧密. 将ZnO/In₂O₃复合空心球组装成薄膜光电极, 研究了其光电催化降解葡萄糖的性能. 结果表明, 700 ℃退火处理的ZnO/In₂O₃复合空心球薄膜电极可产生最高的光致电流密度. 通过光致发光光谱(PL)发现, 与ZnO或In₂O₃空心球相比, ZnO/In₂O₃复合空心球的发光强度猝灭效果明显. 这是由于复合材料中晶界处产生的p-n结电场, 降低了光生电子-空穴对的复合几率, 从而使更多的光生电子可迁移到电极表面.

Preparation of ZnO/In2O3 Composite Hollow Spheres and Their Photoelectrocatalytic Properties to Glucose Degradation

A series of materials consisting of ZnO/In₂O₃ composite hollow spheres were successfully prepared by a two-step process involving D-glucose-assisted hydrothermal and annealing treatments. X-ray diffraction (XRD) patterns suggested that ZnO semiconductors formed in these materials were amorphous, the annealing temperatures were lower than 500 ℃, however, they converted to a wurtzite structure with higher annealing temperatures. Examination by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the hollow sphere morphology of these materials. In addition, the ZnO and In₂O₃ nanoparticles within the spheres were found to interact closely. The photoelectrocatalytic properties of these materials with regard to glucose decomposition were investigated by depositing samples onto indium tin oxide (ITO) glass to fabricate thin-film photoelectrodes. The highest photo-induced degradation current density was observed with the film annealed at 700 ℃. Photoluminescence (PL) spectra clearly showed quenching of the luminescence intensity of these ZnO/ In₂O₃ composite hollow spheres. The p-n junction at the interface between the ZnO and In₂O₃ nanoparticles evidently reduced the recombination of photogenerated electron and holes, enhancing electron transfer to the surface of the photoelectrode.