Synergetic piezo-photocatalytic effect in a Bi2MoO6/BiOBr composite for decomposing organic pollutants

Abstract It is a promising technology to make full use of solar and mechanical energy for degrading organic pollutants. A synergetic piezo-photocatalytic system is constructed successfully by adopting semiconductor materials with piezoelectric effect, which realizes the ideal combination of photocatalytic heterojunction and piezoelectric catalysis. Herein, Bi2MoO6/BiOBr composite with coupled effect of photocatalysis and piezocatalysis are prepared by one-step hydrothermal reaction. Inspiringly, they present a gratifying degradation performance under visible light irradiation and stable ultrasonic vibration, which is much higher than the isolated photocatalysis and piezocatalysis. Especially, 5 wt% Bi2MoO6/BiOBr presents optimum methyl violet (MV, 20 mg/L) decomposition activity (99.6%, 60 min). It can be attributed that the bulit-in piezoelectric potential provided by vibrating p-type BiOBr nanosheets reduces the recombination efficiency of photogenerated carriers at the p-n heterojunction interface effectively.