Solvothermal synthesis of magnetically separable Co–ZnO nanowires for visible light driven photocatalytic applications

Abstract

Magnetically retrievable Cobalt doped ZnO nanowires were synthesised by simple solvothermal method. The prepared Co–ZnO nanowires were analysed with several characterization instruments such as FESEM, XRD, FTIR, VSM, UV–vis spectroscopy, XPS and PL spectroscopy. No other phase has been identified besides wurtzite phase, according to the structural analysis of pure ZnO and Co–ZnO nanowires. As the concentration of Co doping increased, ZnO nanowires' band gap energy dropped. Moreover, ZnO's absorption peak has a minor wavelength shift toward longer wavelengths. Green light emission was detected by PL analysis of ZnO nanowires and also the PL intensity of ZnO nanowires was decreased after cobalt doping. Co–ZnO nanowires exhibited ferromagnetic property. The coercivity and retentivity of Co–ZnO nanowires were increased with increase of Cobalt concentration. Improved visible light photocatalytic activity for the breakdown of methyl orange dye was achieved by Co–ZnO nanowires.