Carbon Materials Containing Single-Atom Co-N₄ Sites Enable Near-Infrared Photooxidation

Near-infrared light occupies 54.3% of the solar spectrum and has greater penetration depth, and its effective utilization is of great significance in the practical application of photocatalysis on a larger scale. However, the development of catalysts that can directly utilize near-infrared light is still a huge challenge. This paper proposes a strategy to directly utilize near-infrared light (excitation wavelength extending to 850 nm) by creating carbon material doped with a high-spin-state Co(II)-N x single-atom site. In the near-infrared-light-irradiated photooxidation of 1,5-dihydroxynaphthalene, the yield of juglone can reach 45% without a significant decrease, even when the catalytic volume is increased by 20 times, which was much higher than that irradiated by 460 nm wavelength (reduced by about 23%). Our study sets the stage for fabricating stable NIR photocatalysts and provides a solution to directly enhance NIR photooxidation in a large-scale manner.