A comparison study of the Bi₂WO₆based composite photocatalysts for the degradation of bisphenol A (BPA) under visible-light irradiation

ABSTRACT

To study the degradation of bisphenol A (BPA) of the different Bi₂WO₆-based composite photocatalyst under visible-light irradiation, a novel Z-scheme Cu₂S/reduced graphene oxide/Bi₂WO₆ (Cu₂S/RGO/Bi₂WO₆) was successfully synthesised by solvothermal-hydrothermal method, andBi₂₅FeO₄₀/RGO/Bi₂WO₆ was introduced for comparative study. The Cu₂S/RGO/Bi₂WO₆ was characterised by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) test and X-ray photoelectron spectrometer (XPS).TheBi₂WO₆,Cu₂S/RGO/Bi₂WO₆andBi₂₅FeO₄₀/RGO/Bi₂WO₆ were used to degrade bisphenol (BPA) under visible light, respectively, and in addition peroxymonosulfate (PMS) was used as an additive for the Cu₂S/RGO/Bi₂WO₆ to degrade BPA. For Cu₂S/RGO/Bi₂WO₆@PMS, the removal ratio of BPA is 91.0% in 40 minutes, which is much higher than pure Bi₂WO₆ (22.0%),Cu₂S/RGO/Bi₂WO₆ without PMS (56.1%) and Bi₂₅FeO₄₀/RGO/Bi₂WO₆ (48.3%). A Z-scheme photocatalytic mechanism was proposed for Cu₂S/RGO/Bi₂WO₆@PMSbased on the results of UV–vis DRS, PL analysis and Mott–Schottky curve. There are four factors that contribute to CuS₂/RGO/Bi₂WO₆with PMS to achieve excellent photocatalytic performance: 1. The larger specific area; 2. the higher absorption capacity of visible light; 3. RGO can act as a very important role to significantly accelerate electron transfer, and 4. PMS can be activated to generate •SO₄⁻ for BPA degradation.

KEYWORDS:

• Photocatalyst
• Cu₂S/RGO/Bi₂Wo₆
• BPA degradation
• PMS
• Bi₂WO₆

Disclosure statement

No potential conflict of interest was reported by the author(s).