Biogenic synthesis and characterization of cobalt oxide nanoparticles for catalytic reduction of direct yellow-142 and methyl orange dyes

The synthesis of cobalt oxide nanoparticles (CoNPs)using plant extracts is convenient, cheap, eco-friendly, less energy-intensive, and eliminate the use of toxic materials. Naturally occurring phytoconstituents such as flavonoids and phenolics in the Taraxacum officinale (T. officinale)plant extract can act as capping and stabilizing agents during CoNPs formation process. This study presents the biogenic synthesis of CoNPs using T. officinale plant extract using sodium borohydride (NaBH ₄ )as a reducing agent. As developed T. officinale CoNPs were designated as TO-CoNPs and initially characterized using various instrumental techniques including UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A broad peak at 319 nm region confirms the successful synthesis of TO-CoNPs. The optimally yielded TO-CoNPs were then employed to test their dye degradation potential against azo dyes, i.e., direct yellow-142 and methyl orange. The time-dependent degradation process was performed for 60 min, and sampling was done with each 15 min interval. As compared to the control sample (trialed in the absence of TO-CoNPs), both test sample (trialed in the presence of TO-CoNPs)showed complete degradation of direct yellow-142 and methyl orange dyes at the end of 60 min treatment cycle. In conclusion, the degradation of both azo dyes suggests that TO-CoNPs may also be exploited against other related and emerging contaminants in an eco-benign and cost-effective manner.