Synthesis of Composite Oxides Derived from Zn-Ni-Al Layered Double Hydroxides and its Use in Photocatalytic Reduction of CO2
Li ZHANG,Qing-man LIANG,Jian-hui YAN,Min-jie ZHOU
Citation :Li ZHANG,et.al, Synthesis of Composite Oxides Derived from Zn-Ni-Al Layered Double Hydroxides and its Use in Photocatalytic Reduction of CO2 International Journal of Advanced Research in Chemical Science 2017,4(4) : 1-10
ZnO/NiO/ZnAl2O4 mixed metal oxides were synthesized through a facile and environment-benign route in which solutions of appropriate amounts of metal salts were mixed with solutions of sodium hydroxide and sodium carbonate to obtain a series of hydrotalcite-like precursors. The precursors in the form of ZnNiAl layered double hydroxides (LDHs) were subject to calcination at suitable temperatures for the generation of composite oxides. The as-obtained samples were characterized by XRD, SEM, TEM, EDS, BET and UV-Vis DRS techniques. The results indicate that there is the generation of well-crystalline ternary ZnO/NiO/ZnAl2O4 photocatalysts high in surface area. The photocatalytic activity of the as-obtained materials was evaluated in the photocatalytic reduction of CO2 under simulated sunlight irradiation. The effects of calcination temperature,amount of sacrificial agent and reaction time on the photocatalytic activity of the samples were investigated. The results indicated that ZnNiAl-LDH precursor calcined at 500 °C show the highest photocatalytic activity, the maximum yield of 2680 umolgcat-1 methanol within 6 h was obtained with 0.04 mol of NaOH and Na2SO3, respectively. The mechanism of CO2 photocatalytic reduction over ZnO/NiO/ZnAl2O4was discussed.