Insight into visible light-driven photocatalytic performance of direct Z-scheme Bi2WO6/BiOI composites constructed in -situ

Bi2WO6/BiOI composites with enhanced photocatalytic performance were constructed in-situ by a hydrothermal routine. The Bi2WO6/BiOI composites were studied by Brunauer -Emmett-Teller (BET), X-ray diffraction patterns (XRD), UV-Vis diffuse reflectance spectra (DRS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), surface photovoltage spectroscopy (SPS), electron spin-resonance (ESR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The results support the coexistence of Bi2WO6 and BiOI in the composites. All the Bi2WO6/BiOI composites display higher separation rate of photoinduced carriers than BiOI. (OH)-O-center dot and O-2(-) were formed in the composite photocatalytic system. Finally, a direct Z-scheme was proposed for the Bi2WO6/BiOI composites.