Construction of 2D/2D g-C3N4/Bi2WO6 heterostructure nanosheets for efficient visible-light-driven photocatalytic elimination of sulfur-containing VOCs

A simple hydrothermal method was applied to synthesize a 2D/2D g-C3N4/Bi2WO6 (CN/BWO) composite photocatalyst for the photocatalytic removal of gaseous methyl mercaptan (CH3SH). The layered structure of CN/ BWO and the C-O-Bi bonds at the interlayer interface were confirmed by thorough characterization techniques. The C-O-Bi bonds were demonstrated to reduce interlayer charge transfer resistance and inhibit photogenerated electron/hole pairs recombination. Therefore, 0.1-CN/BWO exhibited the highest photocatalytic efficiency for CH3SH removal, which was 1.4 times higher than 0.1-CN/BWONF with nanoflower structure, and 5.1 and 1.9 times higher than that of pure g-C3N4 and Bi2WO6. The photocatalytic oxidation pathway and mechanism for CH3SH removal were revealed based on reactive species trapping, electron spin resonance (ESR), and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) tests. This work provides new insights into the design of photocatalysts with high photocatalytic performance and stability for the removal of volatile organic compounds (VOCs).

Automated summary

A 2D/2D g-C3N4/Bi2WO6 composite photocatalyst was synthesized using a hydrothermal method for the removal of gaseous methyl mercaptan (CH3SH) through photocatalytic oxidation. The CN/BWO structure and the C-O-Bi bonds at the interlayer interface effectively reduced electron/hole pairs recombination, resulting in enhanced photocatalytic efficiency. The 0.1-CN/BWO photocatalyst showed the highest efficiency, outperforming other structures and pure g-C3N4 and Bi2WO6. Reactive species trapping, electron spin resonance, and in situ diffuse reflectance infrared Fourier transform spectroscopy provided insights into the photocatalytic oxidation pathway and mechanism for CH3SH removal. This work is significant in developing efficient and stable photocatalysts for the removal of volatile organic compounds.