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

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. Theoretical and experimental studies reveal that defective Sn2+ active sites can boost small organic molecules adsorption and facilitate the interfacial charge separation/transfer in a Z‐scheme flower‐like SnO2−x/g‐C3N4 photocatalytic system by introducing a Sn2+/Sn4+ redox couple. This work provides a more in‐depth exploration of Z‐scheme photocatalytic‐system construction and is beneficial to the development of defect‐engineering approaches with designed photocatalysis performance.