Facile synthesis of double cone-shaped Ag4V2O7/BiVO4 nanocomposites with enhanced visible light photocatalytic activity for environmental purification

Ag4V2O7/BiVO4 photocatalysts with double cone-shaped nanostructure were successfully synthesized by a facile sodium polyphosphate-assisted hydrothermal method. The results demonstrate that coupling Ag4V2O7 with BiVO4 can promote the separation of photoinduced charge carriers and enhance the photon absorption efficiency. Experimental results indicate that Ag4V2O7/BiVO4 composites exhibit the enhanced photocatalystic activity for degradation of methylene blue (MB) and oxidation of NO in high concentrate (1600 ppb) compared to the pure BiVO4 under visible light irradiation (lambda >420 nm). The composite with 0.08 mol%Ag4V2O7 has the highest photocatalytic activity. MB degradation rate can reach 98.48% in 1 h and NO oxidation rate can reach 52.83% in 0.5 h on 0.08-Ag4V2O7/BiVO4, which are about 2.90 and 3.11 times higher than that of pure BiVO4 respectively. The excellent activity can be attributed to the efficient charge transfer between Ag4V2O7 and BiVO4, and active species H+ and O-center dot(2)- play important roles during MB degradation and NO oxidation. In addition, this composite exhibits favorable stability during the cycling experiment, suggesting it may be a promising visible light active photocatalyst for environmental applications. (C) 2017 Elsevier B.V. All rights reserved.