Unraveling Precise Locations of Indium Atoms in g‐C₃N₄ for Ameliorating Hydrogen Peroxide Piezo‐Photogeneration

Increasing active sites in catalysts is of utmost importance for catalytic processes. In this regime, single‐atom dispersing on graphitic carbon nitrides (g‐C3N4) to produce fine chemicals, such as hydrogen peroxide (H2O2), is of current interest due to not only enhancing catalytic performance but also reducing the loading of necessary metals. Hence, we, in this research, engineered g‐C3N4 by atomically dispersing aluminum (Al) or indium (In) sites to provide catalytic active centers via one‐step thermal shock polymerization. The addition of Al and In sites can accelerate the catalytic efficacy owing to the Lewis acid‐base interactions between these metals and oxygen (O2). Under catalytic conditions, the formation of oxygenic radicals would strongly be associated with the enhanced formation of H2O2, confirmed by in‐situ electron paramagnetic resonance (EPR) spectroscopy. Furthermore, the empirical analyses from positron annihilation spectroscopy (PAS) show that In atoms would occupy the near positions of carbon vacancies (VC) to form N‐VC@In‐O bonds. This replacement would produce the highest formation energy based on the density functional theory (DFT) calculations, improving the stability of atom‐dispersive materials. Therefore, via the combination of experimental and theoretical proofs, this study suggests the exact location of In atoms in g‐C3N4 structures, which can help boost the catalytic production of H2O2.This article is protected by copyright. All rights reserved.