synthesis of co and cu codoped zno nanoparticles by citrate gel combustion method: photocatalytic and antimicrobial activity

Zno, single-doped (co-zno, cu-zno), and co-doped zno ((co, cu)/zno) were effectively synthesized by the citrate gel combustion technique. the samples were characterized by uv-visible diffuse reflectance spectroscopy (uv-vis-drs), fourier transforms infrared spectroscopy (ft-ir), x-ray powder diffraction (xrd), scanning electron microscopy (sem), energy-dispersive x-ray spectroscopy (edx) and photoluminescence spectroscopy (pl). the average particle size was 30.33 nm as calculated from xrd patterns for (co, cu)/zno. uv-vis absorption spectrum indicates that the co-doped zno exhibits increased visible light absorption compared to the undoped one. the photoluminescence spectroscopy shows that the separation efficiency of photo-induced electrons and hole is enhanced by the co-doping strategy. (co, cu)/zno nanoparticles demonstrated a strong visible light response and high photocatalytic activity for rhodamine b (rhb) degradation under irradiation by visible light (400-500 nm). the visible-light photocatalytic activity of the prepared (co, cu)/zno may come about because of the incorporation of co, cu atoms in zno, photo-induced electron-hole pairs and extended the spectral response to the visible region. the antibacterial and antifungal activities of zno, co-zno, cu-zno, and (co, cu)/zno were studied respectively with staphylococcus aureus (gram-positive), escherichia coli (gram-negative) ( bacterial strain) and aspergillus flavus, candida albicans (fungal strain). the (co, cu)/zno enhanced the antimicrobial activity.