Improved Visible Light Activity of Copper Oxide/Carbon Nitride Photocatalysts Prepared by Photodeposition for Phenol Degradation

Abstract

A series of copper(II) oxide deposited on carbon nitride (CuO/CN) as visible light-active photocatalyst was successfully prepared via a photodeposition method. The CuO modification was carried out to improve the photocatalytic activity of CN having fast electron-hole recombination. The CuO loading was varied from 0.05 to 0.5 wt% and the photodeposition was carried out at room temperature under UV light illumination. The CuO/CN samples were confirmed to have similar optical properties and functional groups to those of the unmodified CN. Meanwhile, the emission intensity of the CN decreased with the increase of the copper species loading, which could correspond to the suppression of charge recombination on the CN. After a 24-h reaction under visible light irradiation, the best photocatalyst, i.e. the CuO(0.1)/CN, gave 41.7% phenol degradation, which was almost two times higher than the unmodified CN (21.3%). However, the photocatalytic activity decreased when the added copper species was more than 0.1 wt%. Therefore, the optimum amount of copper species deposited on the CN surface would have a prominent contribution to improve the photocatalytic activity. It was also confirmed that holes, hydroxyl radicals, and superoxide radicals were important for the photocatalytic degradation of phenol on the CuO(0.1)/CN.