Facile thermal fabrication of CuO nanoparticles from Cu(II)-Schiff base complexes and its catalytic reduction of 4-nitrophenol, antioxidant, and antimicrobial studies

Abstract

Abstract Herein, we report low-cost and stable CuO NPs from the Cu(II)-Schiff base complexes (Cu(II)-L1; Cu(II)-(3-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)benzene-1,2-diol, Cu(II)-L2; Cu(II)-(2-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)-5-methoxyphenol, and Cu(II)-L3; Cu(II)-(2-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)-4-bromophenol) via thermal decomposition method using an electric muffle furnace at 650 °C for 2 h. CuO NPs were characterized by XRD, TEM, UV–vis DRS, PL, and FTIR to investigate the phase, structure, morphological, and optical properties. It was found that the CuO NPs has a monoclinic phase with approximately 15–25 nm size in a spherical shape. The prepared CuO NPs exhibited more than 99% catalytic conversion in the reduction of 4-NP using NaBH4 in 12 min of reaction time. The evaluation of pseudo-first-order rate constants in the reduction of 4-NP was also investigated. Moreover, CuO NPs can be reused for 5 cycles without significant loss of catalytic activity. In addition, CuO NPs were found as antioxidant and antimicrobial agents, these are evaluated by DPPH scavenging and paper disc methods, respectively.