Photocatalytic Degradation of Organic Pollutants Using Porous g-C3N4 Nanosheets Decorated with Gold Nanoparticles

摘要

In this work, a composite photocatalyst consisted of the porous graphitic carbon nitride (pg-C3N4) nanosheets decorated with in-situ grown gold (Au) nanoparticles were prepared. By characterizing and analyzing chemical compositions and structures, and optical and electrical properties of this Au/pg- C3N4 composite, the excellent photocatalytic performance mainly comes from the following aspects: firstly, pg-C3N4 synthesized from melamine by high-temperature calcination with the assistance of ascorbic acid has larger specific surface area and narrower band gap width than common g-C3N4; secondly, localized surface plasmon resonance (LSPR) effect of Au nanoparticles can enhance light absorption of pg-C3N4 via near-field enhancement-induced excitation; thirdly, the hetero- junction formed between Au nanoparticles and pg-C3N4 nano- sheets can promote electron transfer. Consequently, Au/pg- C3N4 presented the obvious improvement of photocatalytic activity on the degradation of rhodamine B and amaranth under simulated solar irradiation that the kinetic rate constant of degradation reaction can be increased by 3.9 and 5.7 times compared with g-C3N4, respectively.