Fully Exposed Silver Clusters Enabling Highly Efficient Photocatalytic H2O2 Production in Pure Water

Photocatalytic production of H2O2 in pure water holds great potential for sustainable industry. However, this prospect is greatly hindered by its sluggish reaction kinetics involving multistep electron transfer and unstable intermediates. Herein, the fully exposed silver (Ag) clusters were anchored on poly(heptazinimide) (PHI) catalyst, forming a new kind of fully exposed cluster catalysts (FECCs), which can boost photocatalytic generation of H2O2 in pure water, with a rate up to 1075.5 µmol g-1 h-1, surpassing its Ag single atoms counterpart and many recent-reported state-of-the-art photocatalysts. In situ characterization and DFT analysis showed that fully exposed Ag clusters can form the electron-rich centers and optimize the binding energy of the O2 and proton H, which in turn enhances the protonation process of *OOH, reducing the energy barrier of key steps, and finally leading to a high yield of H2O2. Interestingly, its Ag single-atom counterpart was favorable for decomposing the H2O2 into ·OH. Thus, Ag FECCs achieve significantly enhanced tetracycline degradation efficiency with the strategic incorporation of Ag single atoms.