Ricinus communis leaf extract-derived nickel oxide nanoparticles: green synthesis, characterization, photocatalytic degradation of azo dyes, seed nano-priming, and toxicity assay

Green synthesis of nanoparticles is recently advancing due to its easier process to synthesis, low cost of production and nontoxicity. In the current research, Nickel Oxide Nanoparticles were green synthesized from aqueous leaf extract of Ricinus communis . Characterization of biosynthesized nanoparticles was carried out through various analytical techniques such as XRD analysis, Ultraviolet–visible spectroscopy, SEM, EDAX, FTIR, DLS, zeta potential analysis. XRD study revealed that the nanoparticles are crystalline in nature, the peaks correspond to face centred cubic (fcc) and the average crystalline size is observed to be 14.62 nm using the Scherrer equation. SEM analysis revealed the irregular spherical structure of the nanoparticles and EDAX analysis showed the occurrence of Ni and O in the biosynthesized nanoparticles. Photocatalytic degradation activity of NiO NPs to degrade Reactive black and Metanil yellow was carried under sunlight, and the dyes considerably degraded by 93 % and 87 % respectively. A rate constant of 0.00684 min–1 and 0.00507 min-1 was obtained for RB and MY for the degradation. The effect of synthesized on the growth (root and shoot length), and physiological responses (photosynthetic pigments) were studied, and it showed a positive effect on the Raphanus sativus seedlings. Toxicity potential of NiONPs was assessed using Allium cepa and microscopical analysis revealed a dose dependent rise in chromosomal aberrations (sticky and clumped chromosomes, chromosomal breaks, nuclear blebbing). • Green route synthesis of NiO NPs from leaf extract of R. communis. • Characterize the biosynthesized NiO NPs using XRD, FTIR, UV-Visible spectroscopy, zeta potential analysis. • NiO NPs degrades 93 % of Reactive black and 87 % Metanil yellow dye under sunlight. • Seed nano-priming and growth enhancement study was using NiO NPs with biochemical properties.