LAUSR

Abstract Visible light mediated photocatalytic activity of Ni-doped Al2O3 nanoparticles synthesized via precipitation method has been reported in this paper. Ni doping concentration in Al2O3 is varied as 0, 2, 4 and 6 wt%. The presence of diffraction peaks related to monoclinic crystal structure of θ- Al2O3 is evinced from the XRD patterns of the undoped and doped samples. The diffraction peak (0 0 2) appears to be dominant for all the samples and crystallite size decreased from 41 nm to 33 nm with Ni doping. A shift towards higher wavelength in the absorption edge of pure Al2O3 is evinced with Ni doping. PL spectra confirm the presence of peaks related to oxygen vacancies in the samples. Photocatalytic activity tests performed against metanil yellow dye confirmed that the doped samples exhibit better degradation efficiency than the undoped sample. The 4 wt% Ni-doped Al2O3 catalyst exhibits a maximum degradation efficiency of 86.84% after 90 min visible light irradiation which was well acknowledged from its decreased crystallite size, band gap values and improved surface morphology. The results obtained confirmed that the Ni-doped Al2O3 nanoparticles are well suited as visible light mediated catalysts for the degradation of toxic organic dyes.