Novel FeWO4/WO3 nanoplate with p-n heterostructure and its enhanced mechanism for organic pollutants removal under visible-light illumination

In the first time, a novel FeWO4/WO3 p-n heterostructure was constructed through a facile two-step hydrothermal process. The optimal 0.5-FeWO4/WO3 sample exhibited 90% degradation in 2 h toward to methylene blue (MB) and tetracycline hydrochloride (TC) and the total organic carbon (TOC) removal achieved 52% and 40% with 4 h irradiated under visible light irradiation. The enhancement of photocatalytic efficiency can be attributed to the synergistic effects of higher adsorption ability, stronger visible light response, larger BET specific surface area and faster carrier separation and migration rate. The electron spin resonance (ESR) showed that the hydroxyl radical (center dot OH) was the primary active species. Based on the analysis of the energy band position and ESR, a possible carrier transfer mechanism of enhanced performance in the heterostructure was proposed. Furthermore, the possible degradation pathway was discussed combined with liquid chromatography mass-spectrometry (LCMS). This novel heterostructure catalyst with high efficiency may possess a promising application towards the environment issues.