Core@shell NiCo2O4@ZnIn2S4 heterostructured photocatalyst for efficient visible-light Cr(VI) reduction

Reasonable design core@shell heterostructures is essential for efficient photocatalytic reduction of Cr(VI) in water, as such architectures not only enhance light absorption but also facilitate light-induced charge separation and transfer. Herein, ZnIn 2 S 4 (ZIS) nanosheets were grown in situ on NiCo 2 O 4 hollow nanospheres to construct a NiCo 2 O 4 @ZIS heterostructured photocatalyst for efficient Cr(VI) reduction. The optimal 6 wt% NiCo 2 O 4 @ZIS achieves 100 % photocatalytic reduction efficiency for Cr(VI) within 10 min at pH 3, along with excellent cycling stability, outperforming pure ZIS and most previously reported ZIS-based catalysts. The improved photocatalytic activity is attributed to the unique heterostructure and composition of NiCo 2 O 4 @ZIS, where intimate interfacial contact facilitates charge separation and transfer while suppressing charge recombination. Additionally, homogeneous arrangement of ZIS nanosheets over NiCo 2 O 4 raises the quantity of active sites and enhances light harvesting. This study presents a viable strategy for constructing core@shell heterostructured photocatalysts based on ZIS toward highly efficient Cr(VI) reduction.