Plasmonic coinage metal–TiO2 hybrid nanocatalysts for highly efficient photocatalytic oxidation under sunlight irradiation

The conventional methods of Au co-catalyst deposition onto TiO2 surfaces generally do not offer fine tuning of the metal–TiO2 interface for enhanced photoactivity because of the non-uniform distribution of the size and shape of metal nanodeposits. Hence, this study demonstrated the comparative co-catalysis activity imparted to TiO2 by as-prepared coinage metal (Au, Ag and Cu) quantum dot particles of similar sizes (3–5 nm) as a function of their plasmonic interactions with TiO2 under visible light irradiation. The physiochemical and interfacial properties of metal–TiO2 composites are studied by optical band gap, XRD, XPS, TEM, surface area, time resolved spectroscopy, current–voltage characteristics, GC and GC-MS analysis. It was revealed that the optical band gap is shifted to 2.9 eV from 3.2 eV of bare TiO2 and the specific surface area, 50 m2 g−1, of TiO2 is notably reduced to 20–33 m2 g−1 after metal nanoparticles impregnation (M–TiO2) that were found to exist in the Au0 and Ag0, and Cu+2 oxidation states.

Website: http://www.arjonline.org/physical-sciences/american-research-journal-of-chemistry/