Shapes Control of Bi2WO6 Nano-Structures as Photo-Fenton Catalysts for Pulping Wastewater Treatment

Abstract

Bi2WO6 assembled by flower-like microspheres and nanosheets were controllably synthesized through a one-step hydrothermal approach. Multiple technologies, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and UV–Vis diffuse reflectance spectrum (UV–Vis), were carried out to characterize the as-synthesized samples. The photocatalytic efficiency of Bi2WO6 synthesized with a series of temperature and pH values shows different morphologies and photocatalytic properties. The photocatalyst (Bi2WO6) synthesized at 220 °C and pH of 7 exhibited the best photocatalytic performance, with the methylene blue (MB) degradation approaching 91.6% after reaction time of 60 min. Free radical capture experiments indicate that •OH is the primary reactive species in the methylene blue (MB) degradation reaction, h+ and •O2− contribute negligible influence, while the addition of H2O2 significantly improves the photocatalytic activity of Bi2WO6. Biodegraded poplar preconditioning refiner chemical alkaline peroxide mechanical pulp wastewater (PPW) was treated over Bi2WO6 under UV light (Bi2WO6/UV/H2O2); chemical oxygen demand (CODCr) and color degradation rate were 85.8% and 92.0%, respectively. These results show that Bi2WO6 semiconductors can be introduced as an efficient and stable photocatalyst for industry wastewater treatment.