Noble metals-TiO2 nanocomposites: From fundamental mechanisms to photocatalysis, surface enhanced Raman scattering and antibacterial applications

Abstract Plasmonic photocatalyst nanomaterials are rapidly emerging as novel materials for a number of advanced engineering applications. In the present review article, we aim to provide a comprehensive review to the scientific community consisting of interdisciplinary aspect of plasmonic photocatalyst nanocomposites and their multidisciplinary applications in the variety of fields of current interest from energy, environment to biomedical applications. An improved fundamental understanding of the coupling of different nanomaterials has shown great potential in interdisciplinary science with enhanced fundamental properties owing to their synergistic effects. TiO2 photocatalyst with noble metal nanostructures composes plasmonic photocatalyst systems, which show huge potential for multidisciplinary applications due to their high solar energy utilization. These plasmonic photocatalyst systems show enhanced transport properties and visible light activity due to the Schottky and plasmonic effects in presence of noble metal nanostructures. Engineering of their shapes and sizes causes significant variations in the physical and electrical properties adding flavor to the tunability and flexibility in multifunctional applications of the resulting nanocomposites. This not only enhances the photocatalytic and antibacterial activities of TiO2 but also extends its utilization in broad field of energy and environmental applications. The plasmonic nanostructures on TiO2 surface allow them to use as surface enhance Raman scattering (SERS) substrate for ultra-detection of bio-organic molecules. This review details on multifunctional applications with enhanced properties of noble metals-TiO2 nanocomposites in fields of photocatalysis, photovoltaic, SERS and antibacterial activities. Included are the recent developments and progress in multidisciplinary application of these plasmonic photocatalysts. The plasmonic effect and interdisciplinary research have been emphasized for multifunctionality supported by the fundamental mechanisms and theoretical explanations. Specific applications of these nanocomposites in the form of thin films or embedded in polymers have also been discussed in terms of their stability and real practical applications.