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.

High-temperature stabilized defect pyrochlore Bi2−xFexWO6 nanostructures and their effects on photocatalytic water remediation and photo-electrochemical oxygen evolution kinetics

“…Since the alkaline environment contains the dominant OH − , it reacts with Bi 2 O 2 (OH)NO 3 to form a new secondary phase. Under alkaline conditions, the reaction is as follows: 42,43

Fig. 2X-ray diffraction spectrum of Bi 2− x Fe x WO 6 (800 °C).

7Bi 2 O 2 (OH)NO 3 + 2WO 4 2− + 3OH − → Bi 14 W 2 O 27 + 7NO 3 − + 5H 2 OHowever, with Fe inclusion, this new phase completely disappears, which is also consistent with our previous reports.…”

“…Since the alkaline environment contains the dominant OH − , it reacts with Bi 2 O 2 (OH)NO 3 to form a new secondary phase. Under alkaline conditions, the reaction is as follows: 42,43…”

Preparation of Bi3.64Mo0.36O6.55 by reflux method and its application in photodegradation of organic pollution

“…As a green and clean technology, photocatalysis over semiconductors using solar energy has attracted the attention of more and more scienti c researchers in the organic pollutants degradation, heavy metal reduction, hydrogen production, carbon dioxide reduction et al [5][6][7][8][9]. Consequently, many semiconductors such as TiO 2 [2,[10][11][12][13], ZnO [14][15][16] and Bi based compounds (Bi 2 O 3 [17][18][19], Bi 12 TiO 20 [20][21][22], Bi 2 InNbO 7 [23], Bi 2 WO 6 [2,[24][25][26][27]) have widely reported and exhibited a huge potential to solve above problems. However, the narrow light absorption of the catalyst, the effective separation of photogenerated electron-hole pairs, and the active sites at the reaction interface have always limited the application of photocatalysts [28][29][30][31].…”