Biomass derived synthesis of ZnONPs from pristine Zinc, through sequential phyto-assisted oxidation and bio-fabrication protocols

Preparation of Zinc Oxide nanoparticles (ZnONPs), directly from pristine metallic zinc, by using phyto-technology is reported. By quenching the raw molten zinc, in the vegetable oil, trace impurities were removed and the process had increased the hardness of the purified zinc. Further, addition of Eclipta prostrata herbal juice, to the purified zinc, under continuous heating, the molten zinc was oxidized and solidified into ZnO intermediate, with embrittled nature. This process can be viewed as phyto-assisted powdering, that resulted in the embrittlement of processed material, apparently could play a significant role in powder metallurgy. Subsequent bio-fabrication of the intermediate triturated with juice of Aloe vera and biomass enabled incineration, yielded ZnONPs, with 1:1 stoichiometry and the average particle size was found to be 23.24 nm. The role of herbs, was substantiated by the reduction in the particle size of ZnO. UV-DRS studies revealed the characteristic band gap energy of ZnO NPs as 3.11 eV, is in good agreement with the literature report. Further, ZnONPs was characterized by using PXRD, FT- IR, SEM and quantification by ICP-OES. The ZnO-NPs is known as ‘Naga Parpam’ in the Indian traditional Siddha system of medicine used for therapeutic purposes to treat various diseases.