Ag‐Decorated Chrysanthemum‐Like CuO–TiO2 Thin Film: Enhanced Photocatalytic Degradation of Rhodamine B

Abstract

Photocatalysis has attracted attention as a method for purifying pollutants, but how to simply and efficiently prepare catalyst films with high surface areas is still a challenge. Herein, a chrysanthemum‐like CuO–TiO2–Ag photocatalyst is prepared by anodic oxidation and magnetron sputtering. Scanning electron microscopy and energy dispersive spectrometry analyses show that Ag nanoparticles are uniformly modified on the surface of chrysanthemum‐like CuO–TiO2. Moreover, the influences of the thickness of the TiO2 film and the content of Ag nanoparticles on the degradation of rhodamine B (RhB) are studied by controlling the sputtering time. Among the prepared nanocomposites, the chrysanthemum‐like CuO–TiO2‐2.5‐Ag‐2 proves to have the maximal degradation level with regard to RhB by removing 91.16% RhB after 120 min under UV light. This is because the large surface area offers more active sites. In addition, the trapping experiments show that when CuO–TiO2 is decorated by Ag nanoparticles, this contributes to the movement of a number of photogenerated electrons from the conduction band of TiO2 to Ag, thereby improving the efficiency of charge transfer. The findings reveal that the photodegradation efficiency of the prepared nanocomposites in this study is greatly related to the thickness of the TiO2 film and the content of Ag nanoparticles.