Cu2(OH)PO4/reduced graphene oxide nanocomposites for enhanced photocatalytic degradation of 2,4-dichlorophenol under infrared light irradiation

Abstract

Sparked by the growing environmental crises, photocatalytic degradation of chlorophenols with inexhaustible solar energy is expected to be converted into actual applications. Here, we report the preparation of the nanocomposite of Cu₂(OH)PO₄ and reduced graphene oxide (Cu₂(OH)PO₄/rGO) through a one-step hydrothermal method and examined its infrared-light photocatalytic activity in the degradation of 2,4-dichlorophenol (2,4-DCP). As evidenced by the absorption spectra and the degradation of 2,4-DCP, Cu₂(OH)PO₄/rGO exhibited enhanced infrared light-driven photocatalytic activity compared to pure Cu₂(OH)PO₄ and was very stable even after repeated cycling. More importantly, the introduction of hydrogen peroxide (H₂O₂) could combine the photocatalytic and photo-Fenton effects into one reaction system and maximize the infrared light photocatalytic efficiency. Typically, the rate constant of Cu₂(OH)PO₄/rGO and H₂O₂ was more than 6.25 times higher than that of only Cu₂(OH)PO₄/rGO, and almost 10 times greater than the value for pure Cu₂(OH)PO₄. Further, a plausible mechanism for the enhanced photocatalytic properties of Cu₂(OH)PO₄/rGO has been discussed. These findings may help the development of novel hybrid photocatalysts with enhanced infrared light photocatalytic activity for applications in the treatment of chlorophenol-contaminated wastewater.