Fabrication and characterization of novel Z-scheme photocatalyst WO3/g-C3N4 with high efficient visible light photocatalytic activity

Developing a high-efficiency visible light photocatalyst is always a research hotspot in photocatalytic field. In this study, a novel Z-scheme photocatalyst WO3/g-C3N4 with high efficient visible light photocatalytic activity was prepared via ball milling and heat treatment methods. The photocatalyst was characterized by X-ray powder diffraction (XRD), UV-vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron spin resonance (ESR), and photoluminescence (PL). The photocatalytic activity was evaluated by degradation of methylene blue (MB) and fuchsin (BF) under visible light illumination. The results showed that composite WO3/g-C3N4 exhibits a much higher photocatalytic activity than a single g-C3N4. The rate constants of photocatalytic degradation of MB and BF for WO3(5.0 wt.%)/g-C3N4 are 4.77 times and 3.84 times that of pure g-C3N4. The characterization results by physical and chemical methods demonstrated that composite WO3/g-C3N4 is a typical Z-scheme photocatalyst The enhancement of the photocatalytic activity may be attributed to the formation of the Z-scheme system between g-C3N4 and WO3, which could result in the photoexcited electrons of g-C3N4 and photoexcited holes of WO3 participating in oxidation and reduction reactions, respectively. (C) 2014 Elsevier B.V. All rights reserved.