Hydroxyl-Bonded Co Single Atom Site on Boroncarbonitride Surface Realizes Nonsacrificial H2O2 Synthesis in the Near-Infrared Region

Photocatalytic synthesis of hydrogen peroxide (H2O2) from O-2 and H2O under near-infrared light is a sustainable renewable energy production strategy, but challenging reaction. The bottleneck of this reaction lies in the regulation of O-2 reduction path by photocatalyst. Herein, the center of the one-step two-electron reduction (OSR) pathway of O-2 for H2O2 evolution via the formation of the hydroxyl-bonded Co single-atom sites on boroncarbonitride surface (BCN-OH2/Co-1) is constructed. The experimental and theoretical prediction results confirm that the hydroxyl group on the surface and the electronic band structure of BCN-OH2/Co-1 are the key factor in regulating the O-2 reduction pathway. In addition, the hydroxyl-bonded Co single-atom sites can further enrich O-2 molecules with more electrons, which can avoid the one-electron reduction of O-2 to center dot O-2(-), thus promoting the direct two-electron activation hydrogenation of O-2. Consequently, BCN-OH2/Co-1 exhibits a high H2O2 evolution apparent quantum efficiency of 0.8% at 850 nm, better than most of the previously reported photocatalysts. This study reveals an important reaction pathway for the generation of H2O2, emphasizing that precise control of the active site structure of the photocatalyst is essential for achieving efficient conversion of solar-to-chemical.