Au nanoparticles and graphene oxide co-loaded graphitic carbon nitride: Synthesis and photocatalytic application

Abstract

Inhibition of charge-carrier recombination in semiconductors is one of the most efficient methods to enhance the photocatalytic performance in visible light irradiation. Noble metals and graphene oxide (GO) are currently regarded as fine channels to enhance the charge-carrier transfer efficiency. Herein, novel Au nanoparticles and GO co-loaded graphitic carbon nitride (Au/GO/g-C3N4) composite was obtained by a single step ultrasonic chemical process, and the photocatalytic activity was tested in Rhodamine B (Rh B) photodegradation in visible light region. The Au/GO/g-C3N4 composite containing 0.5%Au (molar Au per unit molar of g-C3N4) exhibited excellent photocatalytic activity and might be attributed to the important part of GO nanoslices and Au nanoparticles. An electron transporter and acceptor have been acted by the GO nanoslices to facilitate the charge transfer and against the recombination of photoexcited electron-hole pairs. In the meantime, an electron trap was formed on the Au nanoparticles to separate the charges. Furthermore, it was found that the reactive species of adsorbed OH and holes took part in the reduction and oxidization actions in the photocatalytic process, respectively. The design of the Au/GO/g-C3N4 composite provides a novel route to synthesis of highly efficient photocatalysts in environmental application.