Synthesis and Characterization of rGO@ZnO Nanocomposites for Esterification of Acetic Acid

Abstract

In the present work, the aim is to synthesize reduced graphene oxide (rGO) and zinc:reduced graphene oxide composite catalysts (ZnO:rGO) for esterification of acetic acid with <i>n</i>-heptanol. The physical and chemical characteristics of the rGO and rGO-metal oxide composite catalysts such as textural surface characteristics, surface morphology, thermal stability, functional groups, and elemental analysis were studied. The surface areas of rGO, ZnO_{(0.5 M)}, and ZnO_{(1 M)} were recorded, respectively, at 31.72, 27.65, and 36.19 m² g^-1. Furthermore, esterification reaction parameters such as the reaction time, catalyst dosage, and reaction temperature for acetic acid were optimized to check the feasibility of rGO-metal oxide composites for a better conversion percentage of acetic acid. The optimized catalyst was selected for further optimization, and the optimum reaction parameters found were 0.1 wt % of catalyst, 160 min reaction duration, and 100 °C reaction temperature with a maximal yield of 100%. At 110 °C, the reaction conducted in the presence of 0.1 g of catalyst displayed more yield than the uncatalyzed reaction.