Abstract

Throughout history, the energy crisis has predominantly arisen from inadequate supply rather than depletion of resources. From the utilization of fire to the development of steam engines and, subsequently, the utilization of fossil fuels and renewable energy sources, humanity has consistently adapted to meet its energy needs. Particularly noteworthy, hydrogen stands as a significant and renewable energy source. However, the demand for hydrogen has tripled since 1975, and due to technological limitations and high costs, most of its production still depends on fossil fuels. Various approaches have been employed to address this issue, one of which is photocatalysis, which holds promise in mitigating the adverse effects of fossil fuel production. Nevertheless, this method has limitations regarding light absorption and the recombination of charged particles. Zero and one-dimensional nanostructures, such as nanotubes, have been extensively investigated as potential photocatalysts, as they exhibit unique properties, including a high aspect ratio that facilitates the controlled movement of charges in a single direction. In order to overcome the aforementioned limitations, modifications have been made to these nanostructures.
However, conventional methods employed for these modifications have drawbacks, such as the extensive use of toxic solvents, limited control over the process, time constraints, and lack of reproducibility. In contrast, greener synthesis methods, such as microwave deposition and liquid-assisted resonant acoustic mixing (LA-RAM), have emerged as viable alternatives due to their minimal energy input and reduced reliance on toxic solvents. Moreover, microwave deposition and liquid-assisted resonant acoustic mixing offer advantages such as shorter reaction times, controlled and uniform deposition, scalability, and improved reproducibility, which address the challenges faced by conventional methods. In this study, transitional metals, namely copper and nickel, were decorated onto titania nanoparticles using LA-RAM and titanium nanotubes using microwave deposition. The individual and combined effects of copper and nickel decoration were investigated alongside optimizing some reaction parameters. Compared to conventional noble metal decoration and traditional synthesis, the photocatalytic efficiency of the resulting best outcome proved to be a practical and effective option. This research lays a foundation for further exploration and utilization of greener and more cost-effective methods and metals in synthesizing photocatalysts.