Facile fabrication of Bi2WO6/biochar composites with enhanced charge carrier separation for photodecomposition of dyes

In recent years, biochar has attracted extensive attention in improving the activity of photocatalysts . The surface functional groups of biochar could accelerate the electron transfer in the process of photocatalytic performance. Herein, in this work, different proportions of Bi 2 WO 6 /biochar (BW/BC) photocatalytic composites were prepared using a simple hydrothermal method and applied for removing of Rhedamine B (RhB) under visible light irradiation. Moreover, the morphology and structure of the as-prepared photocatalytic composites were characterized by XRD , SEM, TEM , XPS , UV–vis DRS, the transient photocurrent response and PL spectra . The results showed that photocatalytic composites with flower-like 3D hierarchical superstructures containing the plentiful nanosheets were obtained, which could rapid interfacial charge transfer and efficiently separate electron-hole pairs, and thereby significantly enhanced charge carrier separation and the photocatalytic activity . It was found that BW/BC-5 has the highest photo-catalytic activity and more than 94.9% of the RhB solution were degraded. Furthermore, the kinetic rate of BW/BC-5 composite photocatalyst was 5.27 times more than the pure BW. The •O 2 − part played a huge role in the process of photocatalytic reaction. The mechanism of enhanced photocatalytic activity for BW/BC composite was showed. The result indicated that construction of photocatalytic composites combining Bi 2 WO 6 semiconductor and biochar conductive carbon material is a high efficient way to increase the photocatalytic activity for environmental protection.