A mechanistic study on photocatalytic activity of hydrothermally synthesized titanium dioxide nanowires decorated by silver phosphate

Abstract

Heterostructure semiconductors have attracted increasing attention in the energy, environment, and catalysis domains. This study employed the hydrothermal method to synthesize titanium dioxide nanowires (TNWs) from TiO2–P25 nanoparticles. An effective strategy was used for coupling TNWs with a proper semiconductor with a narrow bandgap (Ag3PO4) for the purpose of enhancing absorption capacity in the visible light area and preventing the recombination of the photo-generated electrons and holes. The Ag3PO4/TNWs heterostructures consisted of Ag3PO4 nanoparticles firmly attached to the TNWs surfaces in varying ratios. The synthesized nanostructures were investigated by the Transmission Electron Microscopy (TEM), BET-BJH, and UV–Vis Diffusion Reflectance Spectra (DRS) techniques, as well as the X-ray diffractometer instrument. The photocatalytic degradation of RhB showed that the Ag3PO4/TNWs heterostructures manifested better photocatalytic performance than the pure TNWs and Ag3PO4. Likewise, the Ag3PO4/TNWs heterostructure photocatalyst reduced the loading of the noble Ag metal and thus decreased the practical application costs of the Ag3PO4 photocatalyst. A detailed mechanism study revealed the effective roles of holes and anion radical superoxides in the photocatalytic activity of the Ag3PO4/TNWs heterostructures.