Abstract
In this work, we reported on the enhanced photocatalytic activity of ZnO nanowires (NWs) modified with cuprous oxide and silver nanoparticles (NPs). ZnO NWs were grown by the solution method and then modified with cuprous oxide NPs, silver NPs, or both (co-modified) by the photoreduction method on paper substrates. We chose low cost, convenient and eco-friendly materials and all the steps were done by low temperature. Therefore, it showed great potential to apply on our daily life. From scanning electron microscopy images, we could confirm the morphologies and compare as-grown NWs with modified ones. The EDS spectra revealed there were no other elements in the materials. In the photoluminescence spectra, the ultraviolet emission of co-modified NWs showed the lowest. Therefore, we could deduce co-modified NWs had the best ability to reduce the combination of electron-hole pairs. The photocatalytic activities of the NWs were conducted by putting 10×10 cm2 paper samples into rhodamine B solution (100 mL, 10 µM) and evaluated the absorption spectrum under the illumination of a 300 W halogen lamp. After data analysis, we could get the first order kinetic constants of all the samples. Among them, the co-modified NWs showed the best efficiency with the highest kinetic constant of 0.022 min-1, which was 1.69 times as high as that of as-grown ZnO NWs. From the analysis, the co-modified NWs had the best ability to reduce the combination of electron-hole pairs and performed the highest degrading rate. To summarize, we were able to fabricate the composite photocatalytic materials with better efficiency by simple photoreduction processes.