Synthesis of WO3 nanofibers decorated with BiOCl nanosheets for photocatalytic degradation of organic pollutants under visible light

Abstract

Notwithstanding intensive research in recent decades, the conspicuous restrictions in photocatalysts still remain as low utilization of visible light, poor charge transfer/separation, and insufficient surface active sites. Designing semiconductor heterostructures as photocatalysts is a promising approach to enhance the photocatalytic efficiency for degrading organic pollutants. In this work, a novel WO3/BiOCl p–n heterostructure photocatalyst with optimal molar ratio was successfully fabricated by growing BiOCl nanosheets on WO3 nanofibers through the electrospinning method followed with a solvothermal process. The optical properties and photoelectrochemical tests indicated that the WO3/BiOCl heterostructures possess high ability of photogenerated charge separation. The photocatalytic performance of the as-obtained materials was assessed by the degradations of rhodamine B (RhB) and phenol in water under visible light. Compared with pure WO3 nanofibers and BiOCl nanosheets, the WO3/BiOCl heterostructure catalysts showed improved photocatalytic efficiencies, and the apparent rate constant of RhB degradation is 0.259 min−1 on the optimal WO3/BiOCl(2) sample, which is about 2.3 times that of pure BiOCl (0.113 min−1). The roles of different active species in the photocatalytic system were determined by active-species-eliminating experiments, revealing that the photogenerated holes play a leading function in the degradation of organic pollutants. The enhanced photocatalysis of WO3/BiOCl(2) heterostructures results from the joint effect of high activity of BiOCl nanosheets, anti-agglomeration of WO3 nanofibers, and well-matched straddling band-structures for charge separation. This photocatalyst presents great potential in the removal of organic pollutants from aquatic environment.