Low-voltage electrophoretic deposition of silver nanoparticles on ZnO nanorods thin films for enhanced visible-light photocatalysis

Abstract

This study focuses on developing visible-light-driven photocatalytic thin films using silver nanoparticle-modified zinc oxide (Ag-ZnO) nanorods. The thin films were prepared using a straightforward electrophoretic deposition method to find the optimal condition, with deposition voltages ranging from 0 to 20 V. Among the samples, the 2V-Ag-ZnO nanorods showed the highest efficiency in degrading indigo carmine dye under visible light. Characterization of the samples confirmed uniform growth of the ZnO nanorods and successful surface modification with Ag nanoparticles. Optical analysis demonstrated that the presence of Ag nanoparticles improved light absorption in the visible range due to the surface plasmon resonance effect, which also helped reduce the recombination of electron-hole pairs. This resulted in better photocatalytic performance compared to unmodified ZnO. Although the reusability tests showed a gradual decrease in photocatalytic efficiency after 4 cycles, the 2V-Ag-ZnO nanorods still performed better than the unmodified ZnO, indicating the benefits of surface modification. The findings suggest that Ag-ZnO nanorod thin films are promising photocatalysts for environmental applications, such as dye degradation, and that electrophoretic deposition is an effective, simple method for fabricating such materials.