CaCO_3/Fe_2O_3/CaFeO_3建筑材料复合催化剂的合成与性能研究

Study on synthesis and properties of CaCO_3/Fe_2O_3/CaFeO_3 composite catalyst as building materials

采用传统的溶胶-凝胶法制备了Fe_2O_3/Ca Fe O_3复合光催化剂,再经超声浸渍负载合成了CaCO_3/Fe_2O_3/CaFeO_3复合光催化剂。物相分析可知,样品中仅含CaCO_3、Fe_2O_3和CaFeO_3的衍射峰,表明通过超声浸渍法合成复合光催化剂时单相光催化剂间不会发生化学反应。光催化实验表明,CaCO_3/Fe_2O_3/CaFeO_3复合光催化剂对大红染料具有良好的光催化活性。实验研究了pH、CaCO_3负载率和过氧化氢添加量对复合光催化剂降解率的影响,得到最佳的催化降解条件:pH=5、CaCO_3负载率为15%(质量分数)、过氧化氢添加量为6mL。结合实验结果,分析了过氧化氢增强CaCO_3/Fe_2O_3/CaFeO_3复合光催化剂的光催化机理。

Fe2 O3/Ca Fe O3 composite photocatalysts was prepared by the traditional sol-gel method and CaCO3/Fe2O3/CaFeO3 composite catalyst was prepared by ultrasonic infiltration.Phase analysis indicated that the as-synthesized Ca CO3/Fe2O3/CaFeO3 composite catalyst consists of the diffraction peaks of CaCO3,Fe2O3 and CaFeO3.In the ultrasonic infiltration process,no chemical reaction occurred in single phase photocatalysts.Photocatalysis experiments indicated that the CaCO3/Fe2O3/CaFeO3 composite photocatalysts exhibits an excellent catalytic activity for the scarlet dye decomposition under simulated sunlight irradiation. In addition,the effects of pH,CaCO3 load ratio,and H2 O2 content have been investigated.The optimum conditions for the degradation of scarlet dye were determined to be as follows：pH =5,CaCO3 load ratio was 15% and H2O2 content was 6 mL.According to the experimental result,the photocatalytic mechanisms of H2O2 enhanced photocatalytic activity of CaCO3/Fe2O3/CaFeO3 composite catalyst.