Production of zinc oxide nanomaterial for generation of bio-oil through maize stalk and catalysis of methylene blue dye

Abstract In this study, zinc oxide nanoparticles are synthesized through a novel, facile, and eco-friendly approach using an extract of Oxalis corniculate leaves. Different characterization techniques were employed, including SEM, XRD, FTIR, and UV–Vis to investigate structural, morphological and functional nature of ZnO NPs. The UV–visible analysis showed λ max at 360 nm for ZnO NPs. The SEM analysis indicates spherical morphology with an average particle of 39 nm. While XRD analysis indicates a hexagonal geometry for the synthesized ZnO NPs. The catalytic performance of ZnO NPs is evaluated through its applications in the pyrolysis of corn cob and reduction of MB dye. All kinetic models show low activation energy in degradation of corn cob biomass using ZnO NPs as compared to pure corn cob. The kinetic parameters i.e., Δ H , Δ S and Δ G were found to be 47.74 kJ/mol, −142.367 J/kmol and 48.55 kJ/mol, respectively. The maximum yield of bio-oil was found to be 66.8 % using 0.6 g ZnO NPs at 450 °C for 20 min reaction time. Synthesized ZnO NPs demonstrated excellent catalytic activity via degradation of methylene blue in 28 min. ZnO NPs catalyzed MB dye followed pseudo-1st order kinetics, in accordance with Langmuir-Hinshelwood mechanism.