Nanosized Zn-In spinel-type sulfides loaded on facet-oriented CeO nanorods heterostructures as Z-scheme photocatalysts for efficient elemental mercury removal.

Developing of effective photocatalysts is of great significance for realizing photocatalytic environment purification. Herein, an interfacial bent bands and internal electric field modulated CeO/ZnInS Z-scheme heterojunction for photocatalytic Hg oxidation. It is found that the charge transfer mechanism of Z-scheme was driven by the interfacial bent bands and internal electric field, which was confirmed by electrochemical measurements, electron spin paramagnetic resonance spectroscopy and density functional theory calculations. Moreover, the (110) dominant CeO nanorods partially converted Ce to Ce and formed oxygen vacancies, and as an electron mediator in Z-scheme systems to further facilitate charge transfer process and molecular oxygen activation. Under the strong synergistic effect between the large specific surface area, Z-scheme heterojunction and oxygen vacancies, the optimized photocatalyst exhibits 86.7% of photocatalytic removal efficiency. This work provides Z-scheme heterojunction photocatalyst design perspective for photocatalytic air purification.