Engineering a staggered type-II Bi 2 WO 6 /WO 3 heterojunction with improved photocatalytic activity in wastewater treatment.

In recent years, the removal organic pollutants from wastewater by advanced oxidation processes, especially photocatalysis, has become a meaningful approach due to its eco-friendliness and low cost. Herein, staggered type-II Bi ₂ WO ₆ /WO ₃ heterojunction photocatalysts were prepared by a facile hydrothermal route and investigated by modern physicochemical methods (X-ray diffraction, scanning electron microscopy, low-temperature nitrogen adsorption-desorption, and diffuse reflectance spectroscopy). The optimized BWOW-5 photocatalyst exhibited a H ₂ O ₂ -assisted photocatalytic methylene blue removal efficiency of 94.1% (k = 0.01414 min ^-1 ) within 180 min under optimal reaction conditions, which is much higher than that of unmodified Bi ₂ WO ₆ and WO ₃ due to efficient separation of the photogenerated charge carriers. The trapping experiments demonstrated that photogenerated hydroxyl radicals and holes play a key role in the photodegradation reaction. Moreover, the optimized BWOW-5 heterojunction photocatalyst exhibited excellent activity in the H ₂ O ₂ -assisted degradation of other pollutants, namely phenol, isoniazid, levofloxacin, and dibenzothiophene with the removal rate of 63.1, 73.6, 95.0, and 72.4%, respectively. This investigation offers a design strategy for Bi ₂ WO ₆ -based multifunctional photocatalytic composites with improved activity for organic pollutant degradation.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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