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 degrees C, 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 degrees C. 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.