Regulating directional transfer of electrons on polymeric g-CN for highly efficient photocatalytic HO production.

Graphite carbon nitride (g-CN) has been widely used in various photocatalytic reactions due to its higher thermodynamic stability and better electronic properties compared to g-CN. However, it is still challenging to endow g-CN with high performance on photocatalytic hydrogen peroxide (HO) production. Herein, potassium and iodine are co-doped into g-CN (g-CN-K, I) for photocatalytic production of HO with high efficiency. As expected, the photocatalytic HO production rate over the g-CN-K, I (2933.4 μM h) reaches to 84.22 times as that of g-CN. The excellent photocatalytic HO production activity is mainly ascribed to the co-doping of K and I, which significantly improves the capacity of oxygen (O) adsorption, selectivity of two-electrons oxygen reduction reaction (2e ORR) and separation efficiency of charge carriers. The density functional theory (DFT) calculations reveal that O molecules are more conducive to being adsorbed on g-CN-K, I. Besides, the result of excited states further indicates that photo-generated electrons can be directionally driven to the adsorbed O molecules, which are effectively activated to form HO. The findings will contribute to new insights in designing and synthesizing g-CN based photocatalysts for the HO production.