Pt/Bi2WO6 composite microflowers: High visible light photocatalytic performance and easy recycle

Abstract

Abstract A series of 1.5–2 μm Pt/Bi 2 WO 6 composite microflowers (mass concentration: 0.5%Pt, 1%Pt, 2%Pt, 4%Pt) assembled by Bi 2 WO 6 nanosquares were synthesized by a hydrothermal synthesis combination with photo-deposition method. The as-synthesized microflowers were investigated by photocatalytic reaction and characterized by powder X-ray diffraction (XRD), N 2 -physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR). The results showed that these hierarchical Pt/Bi 2 WO 6 composite microflowers have superior texture property in aqueous photocatalytic reactions. Moreover, the deposited Pt nanoparticles (NPs) play an important role in promoting the photocatalytic performance in degradation of acid orange II under visible light ( λ > 420 nm) irradiation. The deposition of optimal amount of 1%Pt brings about 2.8 times increase in activity. The deposited Pt NPs over Bi 2 WO 6 nanosquares enhance the visible light absorption, decrease the recombination rate of e − /h + pairs and promote OH radicals production, hence largely boosting the photocatalytic activity. Moreover, the unique hierarchical structures of Pt/Bi 2 WO 6 microflowers benefit their separation and recycle in aqueous photocatalytic reactions.