Z-Scheme over all Water Splitting on Rh/K4Nb6O_(17) Nanosheets Photocatalyst

摘要

Developing a photocatalysis system to generate hydrogen from water is a topic of great interest for fundamental and practical importance. In this study, hydrogen production by a new Z-scheme photocatalysis water splitting system was examined over Rh modified K4Nb6O_(17) nanosheets and Pt/WO3 photocatalysts for H2 evolution and O2 evolution with I/IO3~- electron mediator under UV light irradiation. The H2 evolution photocatalyst, Rh/K4Nb6O_(17) nanosheets with a slit like framework, was prepared by exfoliation of and proton exchange reaction. Pt/WO3 prepared by incipient-wetness impregnation method was used as O2 evolution photocatalyst. The catalysts were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy analysis (XPS), and ultraviolet-visible spectroscopy (UV-vis). These catalysts characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-Vis). In this study, we developed a facile method of preparing K4Nb6O_(17) nanosheets containing Rh nanoparticles. Our results show that I~- concentration and pH of reaction solution have significant influences on the photocatalytic activity. The combination of Rh modified K4Nb6O_(17) nanosheets with Pt/WO3 achieves a very high photoactivity (H2: 4240 O2: 1622 (μmol g~(-1) h~(-1))).