Z‐Scheme Flower‐Like SnO₂/g‐C₃N₄ Composite with Sn²⁺ Active Center for Enhanced Visible‐Light Photocatalytic Activity

Abstract The invention of defect‐engineering motivated Z‐scheme photocatalytic complexes has been treated as an emerging opportunity to accomplish effective carrier separation and electron transfer in hybrid heterojunctions, contributing a novel approach to accomplish modified visible‐light driven photocatalytic performance compared to traditional nanocomposites. Exploring a desired carrier medium is crucial to support impressive electron transportation in Z‐scheme photocatalytic nanocomposites. Here, the role that the Sn²⁺/Sn⁴⁺ redox couple plays in the photocatalytic process is systematically studied by taking the flower‐like SnO₂/layered g‐C₃N₄ with deficient Sn²⁺ reactive sites as an example, where the defect‐engineering can be introduced by heat treatment. The experimental results and computational simulations demonstrate that the deficient Sn²⁺ reactive sites can facilitate small molecule adsorption and boost the interfacial carrier separation and transfer in the photocatalytic procedure by bringing in the Sn²⁺/Sn⁴⁺ redox couple. This work provides a more in‐depth exploration of Z‐scheme photocatalytic‐system construction and is helpful to the development of defect‐engineering approaches with high photocatalysis performance.