Facile synthesis of ZnO nanoparticles using Nigella Sativa extract and its role as catalyst in production of bio-oil and degradation of methylene blue dye

Abstract

Zinc Oxide (ZnO) nanoparticles (NPs) were synthesized using an environmentally benign biogenic approach employing an extract of kernels of Nigella Sativa (kalonji). The presence of primary and secondary metabolites in Nigella Sativa extract acted as the capping and reducing agent. The as-synthesized ZnO NPs were characterized using various advanced techniques i.e., UV, SEM, XRD, EDS, TGA, DSC, and FTIR spectra. UV characterization of ZnO NPs revealed a peak within the 350-400 cm−1 range, confirming their successful formation. XRD spectra revealed that the particles possess a nano-rods and platelets structure, with an average size of 65 nm. XRD analysis revealed that the particles possess a size of 65 nm with a nano-rods and platelets structure. FTIR spectra of the ZnO NPs exhibited a peak at a wavenumber range of 500–600 cm−1. The newly fabricated ZnO NPs were utilized in a pyrolysis reaction for the production of high-yield bio-oil, resulting in a maximum yield of 65.6 % at 350 °C. The spectra of the bio-oil display distinct peaks at 1340 cm−1, 2923.6 cm−1, and 1617 cm−1, which suggest the existence of phenolic and carbonyl chemicals. After incubating for 24 h under UV light, they also demonstrated significant catalytic degradation of methylene blue dye. The highest degradation was recorded to be an average of 71 % in 60 min of UV exposure. Taken together, ZnO NPs developed by eco-benign methods have the potential to be implemented as a novel catalytic system in the production of bio-oil as well as the remediation of dye-harboring industrial wastewater.