Ultra-rapid catalytic reduction of methyl green dye using tetra methyl ammonium bromide derived cobalt nanoparticles

Cobalt nanoparticles (CoNPs) were fabricated from cobalt chloride hexahydrate (CoCl2 & sdot;6H2O) through a novel aqueous phase reduction protocol using sodium borohydride (NaBH4) as reducer and tetra methyl ammonium bromide (TMAB) as stabilizing reagent. As synthesized CoNPs were characterized via different advanced techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and Fourier transform infra-red (FTIR) spectroscopy. The results depict that as prepared CoNPs were spherical in shape, evenly distributed, crystalline in nature and possessed an average diameter of 10 nm. These CoNPs (1.3 mg) were found to play the role of highly efficient catalysts for ultra-rapid reduction of methyl green (MG) designated as a model dye in one minute of time for 0.1 mM (approximate to 45.5 ppm) MG as evident from ultra-violet visible (UV-Vis) spectroscopy. These CoNPs were reused 5 times with 100-94.2 % catalytic efficiency. CoNPs were applied for reduction of MG dye in tap water demonstrated as representative environmental sample with outstanding performance. The application of this catalyst could be extended for rapid reduction of other toxic dyes in several types of aqueous matrices. This study is important because the synthesis of cheaper catalyst like CoNPs is quite easy while its significance is enhanced catalytic reduction efficiency for MG. These findings can be used by our group to solve the issue of environmental contamination especially caused by synthetic dyes like methyl violet, methylene blue, eosin B and so on. We can use the waste water from textile and food industry for this study.