Linkage engineering mediated carriers transfer and surface reaction over carbon nitride for enhanced photocatalytic activity

Abstract

Rational tailoring of the atomic structure of photocatalysts with multiple functions to enhance the carrier transfer efficiency and surface activation of carbon nitride (C₃N₄) is promising and a challenge. Here, we make the first report of a facile strategy to construct amphiphilic carbon and C–O–C chain linked terminal melem units in functional carbon nitride (COCN) via copolymerizing formaldehyde with melem. By integrating the amphiphilic carrier bridge of carbon and C–O–C chains into the framework, the photogenerated carrier mobility and activated species (superoxide radicals, singlet oxygen) as well as surface interaction are significantly improved. Consequently, the optimal tailoring of C₃N₄ attains superior photocatalytic activity for hydrogen production (34.9 μmol h⁻¹) and selective oxidation of sulfide to sulfoxide using air (nearly 100% conversion and selectivity after 3 h of illumination), which is about 7 times higher than that of pristine C₃N₄. This study provides deep insight into and strategies for the atomic tailoring of carrier transfer and surface reaction over organic-based photocatalysts.