A novel step-scheme BiVO4/Ag3VO4 photocatalyst for enhanced photocatalytic degradation activity under visible light irradiation

Over the past few years, the emission of organic pollutants into the environment has increased tremendously. Therefore, various photocatalysts have been developed for the degradation of organic pollutants. In this study, a step-scheme BiVO4/Ag3VO4 composite was synthesized via a hydrothermal and chemical deposition process for the degradation of methylene blue.The composite showed strong redox ability under visible light. The 40%BiVO4/Ag3VO4 composite showed excellent photocatalytic degradation properties with a Kapp of 0.05588 min−1, which is 22.76 and 1.76 times higher than those of BiVO4 (0.00247 min−1) and Ag3VO4 (0.03167 min−1), respectively. The composite showed a stable performance and could retain 90% of its photocatalytic activity even after four cycles. The improved catalytic performance of the composite as compared to BiVO4 and Ag3VO4 can be attributed to its novel step-scheme mechanism, which facilitated the separation of the photogenerated charges and increased their lifetime. The photoluminescence measurement results and transient photocurrent response revealed that the composite showed efficient extraction of charge carriers.