Unraveling Precise Locations of Indium Atoms in g‐C <sub>3</sub> N <sub>4</sub> for Ameliorating Hydrogen Peroxide Piezo‐Photogeneration
Nguyen Hoai Anh, Duc‐Viet Nguyen, Tuyen Anh Luu, Pham Duc Minh Phan, Huynh Phuoc Toan, Pho Phuong Ly, Nguyễn Quang Hưng, Ngoc Linh Nguyen, Seung Hyun Hur, Phạm Thị Huế, Nguyen Thi Ngoc Hue, Minh‐Thuan Pham, Ung Thi Dieu Thuy, Danh Bich, Vinh Ai Dao, Huan V. Doan, Mark A. Isaacs, Minh Chien Nguyen, Woo Jong Yu, Yen‐Yi Lee, Guo‐Ping Chang‐Chien, Hoai‐Thanh Vuong
Abstract
Increasing active sites in catalysts is of utmost importance for catalytic processes. In this regime, single‐atom dispersing on graphitic carbon nitrides (g‐C 3 N 4 ) to produce fine chemicals, such as hydrogen peroxide (H 2 O 2 ), is of current interest due to not only enhancing catalytic performance but also reducing the loading of necessary metals. Herein, g‐C 3 N 4 is engineered 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 (O 2 ). Under catalytic conditions, the formation of oxygenic radicals will strongly be associated with the enhanced formation of H 2 O 2 , confirmed by in situ electron paramagnetic resonance spectroscopy. Furthermore, the empirical analyses from positron annihilation spectroscopy show that In atoms will occupy the near positions of carbon vacancies (V C ) to form NV C @InO bonds. This replacement will produce the highest formation energy based on the density functional theory 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‐C 3 N 4 structures, which can help boost the catalytic production of H 2 O 2 .