Unraveling the Mechanism on Ultrahigh Efficiency Photocatalytic H2O2 Generation for Dual‐Heteroatom Incorporated Polymeric Carbon Nitride

Abstract Photocatalytic hydrogen peroxide (H 2 O 2 ) production from dioxygen and water is regarded as a promising technology since it can achieve sustainable and green solar‐to‐chemical energy conversion. Herein, oxygen and potassium dual‐heteroatom incorporated polymeric carbon nitride (O/KCN) is rationally designed for H 2 O 2 generation with an ultrahigh rate of 309.44 µM h −1 mg −1 , which surpasses that of other C 3 N 4 ‐based photocatalysts. The enhanced performance can be ascribed to the effective light absorption, fast charge transfer/separation, strong oxygen adsorption, and highly selective two‐electron oxygen reduction reaction (ORR). Density functional theory calculations further confirm that the obtained O/KCN is more favorable than others for electrons migrating from β spin‐orbital to π* orbitals of O 2 molecule, thus optimizing O 2 molecule activation to promote the formation of intermediate species *OOH and decrease the energy barrier of H 2 O 2 production. This work not only provides in‐depth insights for the photocatalytic H 2 O 2 generation mechanism, but also lays the foundation for further development of highly active photocatalysts for environmental remediation and energy conversion.