In situ decomposition-thermal polymerization method for the synthesis of Au nanoparticle–decorated g-C3N4 nanosheets with enhanced sunlight-driven photocatalytic activity

Abstract

Plasmonic Au nanoparticle (NP)–decorated g-C3N4 nanosheets were synthesized by a direct in situ decomposition-thermal polymerization method with dicyandiamide and gold chloride trihydrate (HAuCl4·3H2O) as the precursors. Au NPs were closely anchored on the surface of g-C3N4 with high dispersion, and Au/g-C3N4 composites showed strong surface plasmon resonance in the visible light region. The photocurrent density of Au/g-C3N4 composite with 1 wt% Au (0.32 μA/cm2) was 6.3 times higher than that of pure g-C3N4 (0.05 μA/cm2) under simulated sunlight irradiation. The 1 wt% Au/g-C3N4 composite exhibited improved activity in the photodegradation of organic dyes under natural sunlight and enhanced photocatalytic water reduction performance under simulated sunlight illumination due to the uniform distribution of Au NPs and heterostructure at the interface of Au/g-C3N4. This work provided a new platform for the preparation of metal/g-C3N4 to replace traditional photoreduction or chemical reduction method.