Tensile Strain in Tin Oxide Clusters Stabilized by C3N4 for Highly Efficient Visible Light-Driven H2O2 Production

Photocatalytic synthesis of H2O2, as a potential alternative to the industrial anthraquinone process, does not require additional energy input and is a nontoxic and pollution-free process, which has attracted widespread attention. Herein, we successfully anchored the SnO2 clusters into the g-C3N4 through the Sn–N bond (SnO2@g-C3N4) as a highly efficient photocatalyst for visible light-driven H2O2 production. Because of the existence of the Sn–N bond, the thickness of the SnO2@g-C3N4 material is thinner, and the lattice spacing of SnO2 is stretched, achieving an excellent photocatalytic hydrogen peroxide production rate of 1021.15 μmol g–1 h–1, which is 58-fold more than that of the original g-C3N4. Moreover, the turnover frequency of SnO2@g-C3N4 (1.7 min–1) has a huge advantage of 57 times compared with that of the original g-C3N4. The outstanding photocatalytic activity is attributed to the lattice tensile of SnO2 clusters in SnO2@g-C3N4, leading to the decreased d-band center, which can promote the OOH* to HOOH* transformation as the rate-determining step. Meanwhile, the SnO2@g-C3N4 can improve the electron migration from bulk to the catalyst surface, as well as the electron separation, which also plays an important role in activity improvement. This work provides a promising photocatalyst for efficient visible light-driven generation of H2O2.