Fabrication and photocatalytic degradation of reactive blue 19 by CuWO4, Ag3PO4 and CuWO4-Ag3PO4 composites under visible light irradiation

Abstract

CuWO4 nano-powder was synthesized via a hydrothermal reaction using CuCl2.2H2Oand Na2WO4.2H2O in the stoichiometric 1:1 Cu:W molar ratio and sodiumcitrate as raw materials. In addition, Ag3PO4 was synthesized by a precipitationmethod using Na2HPO4 and AgNO3. Finally, CuWO4-Ag3PO4 nanocomposite wassynthesized in a precipitation route using the as-synthesized CuWO4 and Ag3PO4as raw materials. The synthesized materials were characterized by powder X-raydiffraction (PXRD) technique. To investigate the effect of concentration of the basicsolutions on the morphology of the obtained materials, the morphologies of thesynthesized materials were studied by field emission scanning electron microscopy(FESEM) technique. As shown by the FESEM images, the morphology of CuWO4the material was spherical particles. Besides, the photocatalytic performance of theas-synthesized nanocomposites was studied for the degradation of ReactiveBlue 19 (RB19) under directly visible light irradiation. For this purpose, severalreaction parameters affect the degradation yield, such as catalyst amount, pHvalue and absence/presence of light were investigated. The data showed thatthe photocatalytic yield at the presence of light irradiation was more when theThe pH value of the solution was in the acidic range, the weight percent of silverphosphate in the composite mixture was more, and the catalyst amount wasmore. The findings revealed that a 0.05 g nanocomposite containing 0.24 mmoleof Ag3PO4, with an initial pH of 3 and RB 19 volume and concentration of 100 mLand 30 mg/L, respectively, could achieve approximately complete removal after30 min under visible light illumination.