Structural Healing of Deficient Carbon Nitride for Efficient H₂O₂ Photosynthesis

Abstract

Rational vacancies engineering endows semiconductor exotic chemical and physical properties, particularly in photocatalysis. Herein, we report a KBr-mediated bulk vacancies repolymerization strategy for the structural engineering of polymeric carbon nitride (PCN), obtaining a modified catalyst (KCN) with optimized physicochemical properties. Structural characterizations reveal that KBr mediation not only heals bulk vacancies and reconstructs layered stacking but also introduces cyano groups and K+ ions into framework, providing a favorable dynamic driving force for photocatalytic oxygen reduction process. Therefore, KCN exhibits a remarkable H₂O₂ evolution rate of 5488 μmol·g⁻¹·h⁻¹ (λ > 420 nm), which is about 140 folds than pristine PCN. This work provides a promising avenue for designing high-performance photocatalysts.