NiO powder synthesized through nickel metal complex degradation for water treatment.

This study was aimed to synthesize nickel oxide (NiO) powder and its subsequent use in bactericidal activities by exploring the role of interaction at nanoparticle-bacteria interface of E. coli (gram negative) microorganism as well as water treatment by catalysing the two toxic azo dyes reduction reactions by sodium borohydride. The NiO nanoparticles were synthesized through single-step, residue free, in situ thermal decomposition method. Their size, structural and morphological features were confirmed through various analytical tools. An average size of 7-8 nm, high crystallinity and cubic crystal structure of the synthesized nanoparticles was confirmed by XRD and HR-TEM analyses. The NiO nanoparticles revealed virtuous bactericidal activities against pathogenic E. coli. Field emission scanning electron microscopy images were used as the evidence of the cell wall deterioration. The prepared NiO nanoparticles were also used in the catalytic reduction reactions of methyl orange (MO) and congo red (CR) dyes by sodium tetra-borohydrate. The reaction rate constants for the MO and CR were 0.4989 and 0.298 min-1, respectively. The reaction mechanism, comparison with other catalyst and recyclability of the NiO were discussed. [ABSTRACT FROM AUTHOR]