Bimetal Cu and Pd decorated Z-scheme NiGa2O4/BiVO4 photocatalyst for conversion of nitride and sulfide dyes to (NH4)2SO4

Abstract

In general, the conversion of nitride organic dyes in wastewater to ammonium ions (NH4+) depends on the choice of co-catalysts. In this work, a Z-scheme (Cu,Pd)-NiGa2O4/BiVO4 photocatalyst with dual co-catalysts is prepared for photocatalytic conversion of organic dyes to NH4+. Some influence factors, deposited order, molar proportion and deposited amount of Cu and Pd, on the photocatalytic activity are considered. The effects of irradiation time, NO2− and SO32− concentrations and catalyst used times are also evaluated. The results display that the Z-scheme (Cu,Pd)-NiGa2O4/BiVO4 photocatalyst has an excellent performance in conversions of NO2− and SO32−. The generation ratio of NH4+ is 4.4-fold as much as that in the presence of Z-scheme NiGa2O4/BiVO4 photocatalyst. Also, NH4+ as a main product can be generated in the actual photocatalytic conversion of nitride organic dyes. It is wished that this work could provide a feasible route to convert organic dyes in wastewater to selectively generate NH4+ and SO42−, forming (NH4)2SO4 (the main ingredient of fertilizer), respectively.© 2019 Elsevier Inc. All rights reserved.