Synthesis of efficient photocatalysts from sodium bentonite modified Bi2WO6 for the decomposition of oilfield pollutants

Abstract

In this work, the Bi₂WO₆ photocatalyst is first modified by sodium bentonite (SB) to give the SB/Bi₂WO₆ composite photocatalyst, prepared by hydrothermal synthesis. The compounds were characterized through X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity of the catalyst was evaluated by the photocatalytic degradation of rhodamine B under visible light irradiation and bisphenol A under ultraviolet light irradiation, the SB/Bi₂WO₆ exhibited excellent photocatalytic activity compared to Bi₂WO₆. The remarkable photocatalytic activity of SB/Bi₂WO₆ was further confirmed by the photoluminescence spectra and photocurrent response. Furthermore, the recycling experiments confirmed the stability and reusability. The trapping experiments and the electron paramagnetic resonance spin-trap experiments measured the photocatalytic mechanism of SB/Bi₂WO₆ highlighting the main active species during the photocatalytic degradation of the pollutants. This paper offers a new approach for selecting carrier modified photocatalysts, and shows the degradation of oil field pollutants using this photocatalyst.