AUTO-COMBUSTION FACILE SYNTHESIS AND PHOTOCATALYTIC HYDROGEN EVOLUTION ACTIVITY OF Al AND Ni CO-DOPED ZnO NANOPARTICLES

Aluminium (Al) and nickel (Ni) co-doped ZnO nanoparticles were synthesized by facile auto-combustion method and followed by calcinations at 700 degrees C for 3hours. The prepared nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and photoluminescence spectroscopy (PL) techniques. The XRD pattern of Al, Ni co-doped ZnO nanoparticles was found to be hexagonal and clarified the co-existence of Al and Ni into ZnO by peaks shift towards lower 2 theta values. The crystal growth mechanism was successfully suppressed due to Al and Ni doping, confirmed by XRD results. Nearly spherical morphology of prepared samples was confirmed by SEM results. The absorption spectra indicated that optical band gap energy for Al, Ni co-doped ZnO nanoparticles was in range of 3.30-3.27 eV. The band gap energy decreased for low doping concentration and then increased for higher doping concentrations of Al, Ni. The photocatalytic performance of prepared samples was measured in 90 mL aqueous solution containing 15 mL lactic acid (LA) under visible light irradiation and (x=3%) sample showed highest photocatalytic performance for hydrogen evolution (5.68 mmol*h(-1)*g(-1)) as compared to (0.24mmol*h(-1)*g(-1)) for pure ZnO. This useful result of improved photocatalytic performance was attributed to increased absorption of visible light and minimum electron hole pair rate.