Hydroxyl-Bonded Co Single Atom Site on Boroncarbonitride Surface Realizes Nonsacrificial H 2 O 2 Synthesis in the Near-Infrared Region.

Photocatalytic synthesis of hydrogen peroxide (H 2 O 2 ) from O 2 and H 2 O 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 H 2 O 2 evolution via the formation of the hydroxyl-bonded Co single-atom sites on boroncarbonitride surface (BCN-OH 2 /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-OH 2 /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 •O 2 - , thus promoting the direct two-electron activation hydrogenation of O 2 . Consequently, BCN-OH 2 /Co 1 exhibits a high H 2 O 2 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 H 2 O 2 , emphasizing that precise control of the active site structure of the photocatalyst is essential for achieving efficient conversion of solar-to-chemical.