Hierarchically structured Bi2MoxW1-xO6 solid solutions with enhanced piezocatalytic activities

Abstract Hierarchical structure Bi2MoxW1-xO6 (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) solid solutions with high surface area are prepared by hydrothermal method without employing any surfactant. All the as-prepared products are hierarchical microspheres self-assembled by nanosheets. The piezocatalytic performance of Bi2MoxW1-xO6 solid solutions are investigated by the degradation of RhB under ultrasonic vibration. The experimental results show that the x value of Bi2MoxW1-xO6 has great influence on the piezocatalytic efficiency. Among which, the Bi2Mo0.4W0.6O6 presents a high value of the rate constant k of 0.119 min-1 by degrading 97.5% of RhB dye solution in 30 min. It is about 43.4% higher than that of pure Bi2WO6 sample, for which k is 0.083 min-1. Radical trapping test indicates that holes (h+) are the dominating active species in the degradation process. The improved piezocatalytic performance for Bi2Mo0.4W0.6O6 sample ascribes to the larger piezoelectric potential generated under a strained state, which facilitates the transfer of charge carriers and accelerate the piezocatalytic process. Our work presents a new design strategy of piezocatalysts for remediation of water pollution.