纳米Zn1-2xCexFexO微观结构及其对Mg基合金催化性能研究

Research on the microstructure of nanosized Zn1-2xCexFexO and its catalysis effect on Mg-based alloy

采用水热法制备了Ce^4+及Fe^3+离子共掺杂纳米ZnO固溶体.系统研究了Zn1-2xCexFexO固溶体的微观结构及其对Mg基储氢合金的催化性能.XRD结果表明,Ce^4+及Fe^3+离子在ZnO中的固溶限x低于0.03.随掺杂浓度的增大,样品晶粒尺寸及晶胞参数均增加.紫外可见光谱表明,固溶体的能隙明显红移.采用球磨法制备了Mg2Ni-Ni-5 mol%Zn1-2xCexFexO复合材料,对复合材料的电化学储氢性能进行了系统测试.结果表明,掺杂ZnO固溶体能够提高复合材料的放电性能,但容量保持率略有降低.当x=0.02时,固溶体的综合催化性能最佳.Zn1-2xCexFexO固溶体催化性能与晶格中的氧空位浓度及电子跃迁性能等密切相关.

Nanosized Ce^4+and Fe^3+ions co-doped ZnO solid solutions were synthesized via hydrothermal method.The microstructure and catalysis effects on Mg-based hydrogen storage alloy were investigated systemically.XRD results showed that the solid solubility x of Ce^4+and Fe^3+ions in ZnO was lower than 0.03.The crystalline sizes and the cell parameters were increased by enhancing the doped contents.UV-Vis spectra indicated that the band gap energies of the solid solutions were red shift obviously.The Mg2Ni-Ni-5mol%Zn1-2xFexCexO composites were obtained by ball milling method,and the electrochemical hydrogen storage properties were tested systemically.It was shown that the doped ZnO solid solutions could improve the discharge properties of the composites,but the capacity retention ratios were decreased slightly.The solid solutions displayed the best combination catalytic performance when x=0.02.The catalysis effects of the Zn1-2xCexFexO solid solutions were closely associated with the concentration of the oxygen vacancy in the lattice and the electron transition properties.