Oxygen vacancy and Z-scheme heterojunction engineered 3D/2D ZnIn2S4/BiVO4 nanoarchitectures toward boosted visible light photocatalytic performance

Developing high-performance and stable photocatalysts is of particular importance to rapidly and efficiently dislodge persistent toxic and hazardous contaminants. In this work, viburnum opulus-like 3D/2D ZnIn2S4/BiVO4 heterojunction nanostructures with enriched oxygen vacancies (ZnIn2S4/BiVO4-Vo, abbreviated ZIS/BVO-Vo) were successfully constructed. Benefiting from the Z-scheme heterojunction and oxygen vacancies (OVs), the optimal ZIS/BVO-Vo-6 achieves an excellent photocatalytic removal efficiency of 87.71% for tetracycline hydrochloride (TCH) within 75 min irradiated with visible light, which is significantly higher than BVO and ZIS. The quasi-first-order rate constant reaches 2.044×10−2 min−1, which is 1.4 times that of BVO and 1.1 times that of ZIS, respectively. The photocatalytic reaction mechanism and the degradation pathways of TCH were fully explored by employing active species capture experiments, electron spin resonance, and reaction intermediate measurements. As well, the influences of different environmental factors on the photocatalytic removal of TCH were conducted. A significant inhibitory effect was observed for carbonate in both anions and cations; Fulvic acid concentrations also show potential inhibitory effects. Notably, ZIS/BVO-Vo-6 presents high stability in real water environments utilizing 10 mg/L TCH. This work may offer insight into new highly efficient visible-light catalysts based on synergistic engineering of the defect and heterojunctions, and provide a pathway for the elimination of organic pollutants.