Regulating directional transfer of electrons on polymeric g-C3N5 for highly efficient photocatalytic H2O2 production

Graphite carbon nitride (g-C3N5) has been widely used in various photocatalytic reactions due to its higher thermodynamic stability and better electronic properties compared to g-C3N4. However, it is still challenging to endow g-C(3)N(5 )with high performance on photocatalytic hydrogen peroxide (H2O2) production. Herein, potassium and iodine are co-doped into g-C3N5 (g-C3N5-K, I) for photocatalytic production of H2O2 with high efficiency. As expected, the photocatalytic H(2)O(2 )production rate over the g-C3N5-K, I (2933.4 mu M h(-1)) reaches to 84.22 times as that of g-C3N5. The excellent photocatalytic H2O2 production activity is mainly ascribed to the co-doping of K and I, which significantly improves the capacity of oxygen (O-2) 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-2 molecules are more conducive to being adsorbed on g-C3N5-K, I. Besides, the result of excited states further indicates that photo-generated electrons can be directionally driven to the adsorbed O-2 molecules, which are effectively activated to form H2O2. The findings will contribute to new insights in designing and synthesizing g-C3N5 based photocatalysts for the H(2)O(2 )production. (C) 2022 Elsevier Inc. All rights reserved.