Green synthesis of Pd@rGO nanocomposite using Piper (Piper nigrum) leaf extract and its catalytic activity towards alcohol oxidation in water at room temperature

Abstract

A simple in situ methodology for the green synthesis of palladium decorated reduced graphene oxide (Pd@rGO) nanocomposite using green leaf extract of Piper plant (Piper nigrum) has been described. The one-pot synthetic method uses no external stabilizer. The obtained nanocomposite has very low Pd loading (0.012 mol % of Pd), and the size of the nanoparticles anchored in rGO sheets ranged between 6 to 20 nm. The as-synthesized nanocomposite was characterized by FT-IR, UV-vis, TGA, XRD, TEM, EDX, BET surface area measurement, and ICP-AES analysis. The Pd@rGO nanocomposite showed profound catalytic activity for the selective oxidation of primary as well as secondary alcohol in water at room temperature. It is worth noting that, under the optimal condition, it is equally useful for the oxidation of usually nonreactive alcohols like cyclohexanol, nonanol, furfuryl alcohol, etc. The catalyst showed excellent recyclability up to 5th cycles without significant loss of catalytic activity.