1. China National Chemical Industrial Gas Quality Supervision and Inspection Center, Fuzhou 350025, China 2. National Engineering Research Center of Chemical Fertilizer Catalyst at Fuzhou University, Fuzhou 350002, China
Abstract：K4Nb6O17 photocatalyst was successfully synthesized by low-temperature hydrothermal method with layer structure. Considering that a large number of hydroxyl (Nb—OH) and oxygen species (NbO, Nb—O-) exist on the surface of K4Nb6O17 synthesized by hydrothermal method, Ag(en)+2 precursors were employed to synthesize Ag/K4Nb6O17 heterostructure photo-catalysts with highly dispersed Ag. Photocatalytic performance evaluation results show that the photodegradation rate of MO for K4Nb6O17 was remarkably improved when a small amont of Ag was loaded. The best loading dose of Ag is 0.5 at%. Based on various characterizations results of XRD，FTIR，UV-Vis DRS，XRF and TEM, the photocatalytic mechanism of Ag/K4Nb6O17 heterostructure catalysts was illuminated in detail and the conclusions were drawn as follows: (1) K4Nb6O17 nanocrystals serve as electron and hole sources for degradation of an organic dye; (2) Ag nanoparticles on the surface of K4Nb6O17 nanocrystals act as a sink for the electrons, promote interfacial charge-transfer kinetics between the metal and semiconductor, improve the separation of photogenerated electron-hole pairs, and thus enhance the photocatalytic activity of Ag/K4Nb6O17 photocatalyst.
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