Preparation of Au/g-C3N4 composite particles and photocatalytic reduction of p-nitrophenol

Abstract

In order to solve the problem of photo-generated electron-hole separation which affects g-C3N4 photocatalytic acti-vity, Au/g-C3N4 composite particles are in situ prepared. The morphology, microstructure and composition of as-prepared Au/g-C3N4 composite particles were characterized by TEM, SEM, XRD, XPS and FTIR, the photoelectric property of the composite particles is also characterized by UV-vis DRS, PL and EIS, and the catalytic activities were examined using the reduction of 4-NP as a model reaction. The results show that the laminated g-C3N4 is hexagonal crystal, while the gold nanoparticles dispersing between the lamella of the g-C3N4 are face-centered cubic crystallites. The visible-light absorption and electron-hole separation efficiency of g-C3N4 matrix are improved by the introduction of gold nanoparticles. When the mass fraction of Au is 0.5%, the amount of substance ratio of sodium chloroaurate and sodium citrate is 1∶3, the Au/g-C3N4 composite demonstrates the best photocatalytic activity. The composite catalyst has strong visible light responsiveness and significantly higher catalytic activity than pure g-C3N4, which provides a theoretical basis for the synthesis of g-C3N4 photocatalyst with high photocatalytic activity.

Keywords

• catalytic chemistry
• carbon nitride
• gold nanoparticles
• composite particles
• p-nitrophenol
• photocatalytic reduction