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A Z-scheme BiVO 4 /NiCo 2 O 4 (BVO/NCO) heterojunction structure was constructed by modifying optimal ultrathin nickel–cobalt (NiCo 2 O 4) spinel nanosheets on BiVO 4 as an efficient photocatalyst toward water oxidation, which deliver an excellent photocatalytic O 2 evolution performance of 1640.9 μmol∙g−1∙h−1 by reducing the energy barriers and enhancing the separation and transfer of photogenerated carriers. [Display omitted] The sluggish water oxidation process is a severe obstacle for solar-driven water splitting. Therefore, it is imperative to develop a suitable photocatalyst with reduced energy barrier for strong oxidation. In this study, a Z-scheme BiVO 4 /NiCo 2 O 4 (BVO/NCO) heterojunction system was designed by decorating ultrathin nickel–cobalt (NiCo 2 O 4) spinel nanosheets on BiVO 4 as an efficient photocatalyst for water oxidation. The unique structure of the system significantly reduced the energy barrier and improved the oxidation ability of BiVO 4 to efficiently enhance the separation and transfer of the photogenerated carriers. Thus, the photocatalyst delivered an excellent O 2 evolution performance of 1640.9 μmol∙g−1∙h−1 and showed 124% improved efficiency as compared to pristine BiVO 4 and a quantum efficiency of 5.39% at 400 nm for O 2 evolution. Additionally, the theoretical calculations revealed that the formation of *OOH was the rate-determining step for water oxidation. The decoration with NiCo 2 O 4 significantly reduced the energy barrier between *O and *OOH, which eventually improved the photocatalytic performance of BVO/NCO. The results hold great promise for the potential application of spinel-based materials in efficient photocatalytic O 2 evolution and offer fundamental insights into the design of efficient water oxidation heterojunctions. [ABSTRACT FROM AUTHOR]

A fantastic 2D/1D hierarchical layered ZnIn 2 S 4 /TiO 2 hetero-structure is reported as an efficient catalyst for in- situ H 2 O 2 production via 2-electrons oxygen reduction (ORR) process and be activated to high concentration hydroxyl radical (•OH) for water purification under visible light irradiation. [Display omitted] • Solar-driven H 2 O 2 synthesis to purify water via cascade reaction. • A fantastic 2D/1D hierarchical layered heterojunction of ZnIn 2 S 4 /TiO 2. • ZnIn 2 S 4 effectively promote the activation of in- situ generated H 2 O 2. • The superior H 2 O 2 production rate arrives 1530.59 μmol h−1 g−1. Hydrogen peroxide (H 2 O 2) is a significant green oxidant for environment and new energy, especially for Fenton-like system. Onsite production and sustainable consumption of H 2 O 2 are the two critical challenges. Here, a fantastic 2D/1D hierarchical layered ZnIn 2 S 4 /TiO 2 heterojunction is reported as an efficient catalyst for in- situ H 2 O 2 production via 2-electrons oxygen reduction (ORR) process and be rapidly activated to high concentration hydroxyl radical (•OH) for water purification under visible light irradiation. The high-quality catalyst enables superior H 2 O 2 production rate of 1530.59 μmol h−1 g−1 with an external quantum efficiency of 10.39% illuminated at 400 nm, is much higher than that of reported photocatalysts. The bimetallic sulfide ZnIn 2 S 4 can effectively promote the activation of H 2 O 2 due to the unsaturation of sulfur atoms, so that the wastewater containing tetracycline (50 ppm) can be degraded by 90% only within 60 min by ZnIn 2 S 4 /TiO 2 via this cascade reaction. This work provides a novel strategy and ZnIn 2 S 4 -based catalyst for photocatalytic Fenton-like reaction. [ABSTRACT FROM AUTHOR]