Photoelectrocatalytic detoxification and cytotoxicity analysis of deoxynivalenol over oxygen vacancy-engineered WO3-x film with low bias

A surface oxygen vacancy-engineered WO3-x film with enhanced photoelectrocatalytic (PEC) activity for the detoxification of deoxynivalenol (DON) was successfully synthesized via an improved sol-gel method. The presence of oxygen vacancy was verified by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectra and electron spin resonance spectroscopy. The introduction of oxygen vacancy into WO3-x film substantially enhanced its absorption in visible region, and facilitated its transfer and separation of photogenerated charges. This made the WO3-x film to have excellent PEC activity for the detoxification of DON under visible light illumination at a low bias of +0.3 V. The percentage of DON removed was up to 86.4% after being treated with PEC for 2 h. When the bias potential applied was further increased, there were no obvious changes in the degradation efficiency of the film. The cell viabilities were dramatically enhanced with prolonged time, which were over 95% after 2 h PEC treatment compared to the control. Through the analysis of eight intermediates that were separated and identified by high performance liquid chromatography-mass spectrometry, it can be concluded that the reduction of DON and the cleavage of double bond at C9-C10, epoxy group at C12-13 and hydroxyl group at C3 in DON could greatly reduce the toxicity, and the detoxification mechanism of this PEC system was proposed. This work can provide further insights into DON detoxification using PEC system with low bias.