Green Synthesis of Au-Ag@TiO2 Nanocomposite for Photocatalytic Oxidation of Substituted Benzyl Alcohols

The scaling-up of methodologies in the oxidation of alcohols to carbonyl compounds faced widespread hindrance in industries due to large-scale use of toxic and expensive metal oxidants. Novel, cost-effective and eco-friendly approaches need to be developed to address these problems. Bimetallic nanoparticles (BMNPs) show synergistic effects at atomic level, which makes them excellent catalysts for organic transformations. Transition metal nanocomposite with unique physicochemical properties and high surface area offers a promising alternative to traditional catalysts. Herein, an environment-friendly methodology was adopted for the synthesis of Au-Ag BMNPs using phenolic-rich Ocimum basilicum (L.) leaf extract, which was then incorporated into TiO2 matrix for the synthesis of plasmonic Au-Ag@TiO2 nanocomposite. The formation of the nanocomposite was confirmed through analytical characterizations, such as UV-Vis. DRS, FT-IR, PL, SEM, TEM and XRD. The nanocomposite exhibited excellent catalytic activity in the selective oxidation of primary and secondary alcohols in aqueous media using H2O2 as an oxidant under visible light irradiation at room temperature. The nanocomposite also demonstrated good reusability of 84 % in the fifth cycle, which established its promising candidature for wide-scale applications. This work holds significant relevance for industries dealing with pharmaceuticals and personal care products, and thus, offers sustainable solution for organic transformations.