Efficient bifunctional piezocatalysis of Au/BiVO4 for simultaneous removal of 4-chlorophenol and Cr(VI) in water

• Published in: Applied catalysis. B, Environmental Vol. 259; p. 118084
• Main Authors: Wei, Yan, Zhang, Yiwen, Geng, Wei, Su, Hanrui, Long, Mingce
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2019; Elsevier BV
• Subjects: Bifunctional catalysis; Bismuth oxides; Chlorophenol; Chromium; Environmental cleanup; Gold; Gold modified bismuth vanadate; Hexavalent chromium; Hydrogen peroxide; Nanoparticles; New technology; Oxidation; Piezocatalytic effect; Piezoelectricity; Ultrasonic vibration; Vanadates; Hydrogen peroxide; Bifunctional catalysis; Piezocatalytic effect; Gold modified bismuth vanadate; Ultrasonic vibration
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.118084

[Display omitted] •The piezoelectric effect of Au/BiVO4 is characterized by PFM measurements.•Au/BiVO4 is used as a bifunctional piezocatalyst for removal of pollutants in water.•Simultaneous removal of 4-chlorophenol and Cr(VI) is achieved by piezocatalysis.•H2O2 and OH induced mechanism on Au/BiVO4 piezocatalysis is proposed. Piezocatalysis induced by polarization of piezoelectric materials is considered as an emerging technology in environmental cleanup. In this work, a piezoelectric material, Au nanoparticles modified BiVO4 (Au/BiVO4) is synthesized and its piezoelectric response is observed by piezo-response force microscopy. Au/BiVO4 is used as a bifunctional piezocatalyst for simultaneous removal of 4-chlorophenol (4-CP) and hexavalent chromium (Cr(VI)) upon ultrasonic vibration, with 91% and 83% of removal efficiency in 120 min, respectively. The piezocatalytic performance of Au/BiVO4 increases with the increase of ultrasonic power and the decrease of pH. The main active species for 4-CP oxidation and Cr(VI) reduction are determined to beOH and H2O2, respectively, since a significant formation rate ofOH is estimated by a probe method, and a high amount of H2O2 accumulation is directly detected. This study provides understanding on the piezocatalysis mechanism and brings new insights for development of piezocatalysis for multifunctional environmental applications.