One-step route for Z-scheme Al2(WO4)3/Bi2WO6 heterojunction toward superior photoelectric and photocatalytic performance

Abstract

Herein, Al2(WO[Formula: see text]/Bi2WO6 heterojunctions with [Formula: see text]-type structure were successfully prepared by a one-step hydrothermal method. Moreover, the effects of different composite ratios on the properties of materials were explored. The electrochemical tests and photocatalytic degradation experiments showed that the corresponding Al2(WO[Formula: see text]/Bi2WO6 heterojunctions all exhibited improved electrochemical performance and photocatalytic performance than that of the bare Bi2WO6 material. Especially, when the molar ratio of Al to Bi was 2:1, the obtained Al2(WO[Formula: see text]/Bi2WO6 heterojunction displayed the optimal photoelectric and photocatalytic performance. In detail, it depicted the highest photocurrent density, the smallest resistance and the fastest charge transfer rate. What’s more, the RhB solution (10 ppm) could be completely degraded in 30 min under visible-light irradiation, and the removal rate was almost 1.6 times than that of pure Bi2WO6 nanosheets. In the same condition, it also exhibited excellent photocatalytic performance for the degradation of tetracycline (TC) solution (10 ppm) and the K2Cr2O7 solution (40 ppm). These results fully manifested that the constructed Al2(WO[Formula: see text]/Bi2WO6 heterojunction possessed superior photoelectric conversion capacity and outstanding photocatalytic performance. Moreover, based on the obtained experimental results, a [Formula: see text]-scheme mechanism of catalytic degradation of RhB and TC under simulated solar light was proposed and discussed.