Abstract:

TiO2 photocatalyst is a promising material for different kinds of applications, including air and water purification, hydrogen production, and self-clean surfaces. It is usually combined with other materials to improve its charge separation as well as its activation under solar illumination. However, using such an approach is not suitable for practical photocatalytic applications because noble metals are too expensive. Therefore, cost-effective metals (e.g., copper, nickel, etc.) should be also considered instead of noble metals. In this study, we prepared photocatalytically active TiO2 thin films decorated with copper (Cu) nanoclusters (NCs) to improve the charge separation. Here, the metallic Cu NCs were deposited on TiO2 thin surface by a photocatalytic deposition process (under ultraviolet (UV) illumination). The morphology, size, and surface coverage of Cu NCs on TiO2 were varied by controlling the UV illumination time. Results showed that the optimum surface coverage (3.04 %) leads to a remarkable increase in photocatalytic performance compared to bare TiO2. However, depositing more Cu NCs with bigger sizes and higher surface coverage (7.08 %) decreased the overall photocatalytic activity. This might be due to the blocking of UV light incoming to the TiO2 thin film by bigger Cu NCs on the surface. The presented Cu-TiO2 hybrid system would be a good alternative to conventional co-catalyst systems which are composed of expensive metals (Au, Ag, Pt, etc.) and TiO2 structures.

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