Facile synthesis of Co3O4 and ZnO nanoparticles by thermal decomposition of novel Co(II) and Zn(II) Schiff base complexes for studying their biological properties and photocatalytic degradation of crystal violet dye

Abstract

Utilizing the metal complexes as low-cost precursors for the synthesis of metal oxide nanoparticles has been regarded as one of the most suitable and practical techniques that produce nanoparticles with low crystallite sizes. So, in this paper, Co3O4 and ZnO nanoparticles were facilely synthesized by thermal decomposition of novel Co(II) and Zn(II) Schiff base complexes. The Schiff bases, which were abbreviated as E1 and E2, were synthesized by condensation of 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol with 4-(dimethylamino)benzaldehyde and 2,4-dihydroxybenzaldehyde, respectively. The Co(II) and Zn(II) complexes were synthesized by condensation of Schiff bases with CoCl2•6H2O and ZnCl2, respectively. The Schiff bases, complexes, and nanoparticles were characterized using different tools such as 1HNMR, FT-IR, CHNS elemental analysis, TGA thermal analysis, XRD, HR-TEM, and UV–Vis spectrophotometer. The average crystallite size of ZnO samples, which were synthesized from the ignition of ZnE1 and ZnE2 complexes, is 34 and 44 nm, respectively. The average crystallite size of Co3O4 samples, which were synthesized from the ignition of CoE1 and CoE2 complexes, is 33 and 45 nm, respectively. The Co3O4 and ZnO nanoparticles were utilized for the photocatalytic degradation of crystal violet dye in aqueous media under UV illumination in the presence of hydrogen peroxide. The maximum% degradation of crystal violet dye using ZnO in the absence and presence of H2O2 is 78 and 98%, respectively. The maximum% degradation of crystal violet dye using Co3O4 in the absence and presence of H2O2 is 67 and 95%, respectively. Furthermore, the biological activities of the synthesized samples were studied against some bacterial and fungal strains. The complexes show moderate effect against bacterial strains whereas did not show any effect against fungal strains except ZnE1, CoE2, and ZnE2 which have moderate effect against Candida albicans fungi. The Co3O4 and ZnO nanoparticles show moderate effect against bacterial strains and did not show any effect against fungal strains.