Photoelectrocatalytic degradation of deoxynivalenol on CuO-Cu2O/WO3 ternary film: Mechanism and reaction pathways

Highlights: • Efficient degradation of DON by photoelectrocatalysis is achieved. • CuO-Cu₂O/WO₃ ternary film exhibits enhanced visible-light PEC activity. • A Z-scheme and type-II PEC mechanism is proposed for CuO-Cu₂O/WO₃ film. • Sixteen intermediate products are identified during PEC degradation process of DON. A ternary film of CuO-Cu₂O/WO₃ possessing high visible-light photoelectrocatalytic (PEC) performance was prepared for degradation of deoxynivalenol (DON). In such a ternary film, the introduction of CuO-Cu₂O significantly promoted the absorption of WO₃ in the visible region and reduced the recombination of photogenerated charge carriers. As a result, the CuO-Cu₂O/WO₃ film exhibited high photoelectrochemical activity under visible light illumination. The PEC performance of CuO-Cu₂O/WO₃ film was evaluated by the decoloration of Rhodamine B. The result indicated that the CuO-Cu₂O/WO₃ film exhibited higher PEC activity than WO₃ or CuO-Cu₂O film. When the CuO-Cu₂O/WO₃ film was applied to study the removal of DON, the degradation efficiency reached 87.6% after 180-min PEC treatment. According to reactive oxygen species detected by electron spin resonance analysis, a Z-scheme and type-II PEC mechanism was proposed for this ternary film. Furthermore, the intermediates formed during the PEC degradation process of DON were separated by high-performance liquid chromatography and identified with liquid chromatography-mass spectrometry. On the basis of sixteen intermediate products identified, we proposed a degradation pathway for DON in such a PEC system.