2WO 6/TiO 2 heterojunction under visible light irradiation]]>

摘要

Bi2WO6/TiO2heterojunction photocatalysts with two different microstructures were controllably fabricated via a facile two-step synthetic route. XRD, XPS, SEM, TEM, BET-surface, DRS, PL spectra, photoelectrochemical measurement (Mott-Schottky), and zeta-potential analyzer were employed to clarify structural and morphological characteristics of the obtained products. The results showed that Bi2WO6nanoparticles/nanosheets grew on the primary TiO2nanorods. The TiO2nanorods used as a synthetic template inhibit the growth of Bi2WO6crystals along the c-axis, resulting in Bi2WO6/TiO2heterostructure with one-dimensional (1D) morphology. The photocatalytic properties of Bi2WO6/TiO2heterojunction photocatalysts were strongly dependent on their shapes and structures. Compared with bare Bi2WO6and TiO2, Bi2WO6/TiO2composite have stronger adsorption ability and better visible light photocatalytic activities towards organic dyes. The Bi2WO6/TiO2composite prepared in EG solvent with optimal Bi:Ti ratio of 2:12 (S-TB2) showed the highest photocatalytic activity, which could totally decompose Rhodamine B within 10?min upon irradiation with visible light (λ?>?422?nm), and retained the high photocatalytic performance after five recycles, confirming its stability and practical usability. The results of PL indicated that Bi2WO6and TiO2could combine well to form a heterojunction structure which facilitated electron–hole separation, and lead to the increasing photocatalytic activity.