Enhanced visible-light photocatalytic performance of highly-dispersed Pt/g-C3N4 nanocomposites by one-step solvothermal treatment

Abstract

A highly dispersed Pt/g-C₃N₄ nanocomposite photocatalyst was successfully prepared by depositing platinum nanoparticles (NPs) onto the surface of g-C₃N₄ with uniform size. The nanocomposites were applied as an efficient visible-light-driven photocatalyst for the degradation of methyl orange (MO) and tetracycline hydrochloride (TC). The sample with a Pt loading amount of 2% exhibited the highest photocatalytic performance, about 7.82 (MO) and 4.30 (TC) times higher than that of the pure g-C₃N₄. The enhancement of the photocatalytic performance was attributed to the rapid separation of generated electron hole pairs resulting from the hybrid effect, which was confirmed by XPS spectra, photocurrent response experiment, electrochemical impedance spectroscopy measurements and photoluminescence spectra. As confirmed by X-ray photoelectron spectroscopy, there is a strong interaction between Pt NPs and g-C₃N₄; the delocalized pi bond in g-C₃N₄ with a high local electron density donates lone pair electrons to the empty d orbitals of Pt atoms. The combination between g-C₃N₄ and Pt promotes the separation of electron–hole pairs.