Photocatalytic deposition of noble metals on 0D, 1D, and 2D TiO2 structures: a review

In recent years, extensive research on noble metal–TiO2 nanocomposites has demonstrated their crucial role in various applications such as water splitting, self-cleaning, CO2 reduction, and wastewater treatment. The structure of the noble metal–TiO2 nanocomposites is critical in determining their photocatalytic properties. Numerous studies in the literature describe the preparation of these nanocomposites with various shapes and sizes to achieve tunable photocatalytic performance. However, achieving a stable coupling between the noble metal and the TiO2 surface remains a challenge for long-term use. Photocatalytic deposition is one of the most promising approaches to obtain well-defined noble metal structures on TiO2 surfaces with strong adhesion. Noble metal nanoparticles (NPs) can be quickly grown on the TiO2 surface under light exposure. However, various parameters such as the pH, temperature, precursor, and electron sacrificial agent affect the size and distribution of the deposited particles. In this review article, we look at the critical parameters that influence the photocatalytic deposition of noble metals on major TiO2 morphologies, classified as 0D (NPs and nanocrystals), 1D (nanotubes and nanowires), and 2D (thin films).