Designing all-solid-state Z-Scheme 2D g-C3N4/Bi2WO6 for improved photocatalysis and photocatalytic mechanism insight

Abstract

Bi2WO6 was modified by two-dimensional g-C3N4 (2D g-C3N4) via a hydrothermal method. The structure, morphology, optical and electronic properties were investigated by multiple techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy spectra (XPS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Ultraviolet-visible diffuse reflection spectroscopy (DRS), photocurrent and electrochemical impedance spectroscopy (EIS), electron spin resonance (ESR), respectively. Rhodamine B (RhB) was used as the target organic pollutant to research the photocatalytic performance of as-prepared composites. The Bi2WO6/2D g-C3N4 exhibited a remarkable improvement compared with the pure Bi2WO6. The enhanced photocatalytic activity was because the photogenerated electrons and holes can quickly separate by Z-Scheme passageway in composites. The photocatalytic mechanism was also researched in detail through ESR analysis. Keywords: All-solid-state, Z-Scheme photocatalyst, 2D g-C3N4, Bi2WO6, Photocatalysis