Study On The Synthesis And Photocatalytic Property Of A₂BB′O₆(A=Ba,Sr; B=Ca,Mg; B′=Mo,W) For Water Decomposition

Hydrogen is an excellent energy source with high efficiency and no pollution. The photocatalytic decomposition of water to hydrogen using semiconductor as photocatalyst is a clean and renewable method which is of both theoretical and potentially practical significance. In this paper,double perovskites A2BB′O6(A=Ba,Sr;B=Ca,Mg;B′=W,Mo) were prepared and its photocatalytic performance was studied for the first time. The influence of preparation conditions on the sample properties including purity, apparent form and photocatalytic performance after loading NiO or Ag, was studied.Using nitrate or oxide/hydroxid of A and B, ammonium molybdate/ammonium tungstate as raw materials and citric acid as chelating reagent, double perovskite oxides A2BB′O6(A=Ba,Sr;B=Ca,Mg;B′=W,Mo) were synthesized by sol-gel method. The sample were characterized by XRD and SEM, and the photocatalytic activity of the sample loaded NiO or Ag was investigated. The preparation conditions, including ratio between citric acid and metal ion, calcination temperature of precursor and dosage of nitric acid in sol preparation, were optimized. Ba2CaMoO6 and Sr2CaMoO6 with high purity were prepared successfully.Double perovskite oxides A2BB′O6(A=Ba,Sr;B=Ca,Mg;B′=W,Mo) were synthesized by semi-wet method with nitrate or oxide/hydroxid of A and B, ammonium molybdate/ammonium tungstate as raw materials. The samples were characterized by XRD and SEM. The photocatalytic activity of the samples after NiO loaded was investigated. The preparation conditions, including pH and calcination temperature of precursor were optimized, and the influence of second calcination was also studied. Ba2CaWO6, Ba2MgWO6 and Sr2MgMoO6 with high purity were prepared successfully. Using Ba2CaWO6 loaded NiO as catalyst, the hydrogen production rate could reach to 1.3μmol/h under ultraviolet radiation.