【摘要】 通过高温固相法对醋酸镧（C₆H₉O₆La·x H₂O）与高钼酸铵(（NH₄）₆Mo₇O₂₄·4H₂O)在一定条件下热解制备非Pt催化剂La₂Mo₂O₇（La₂O₃-2MoO₂）。进一步采用2种方法将La₂Mo₂O₇与多壁碳纳米管（MWCNTs）进行复合,一种是将La₂Mo₂O₇喷涂到MWCNTs表层之上得到La₂Mo₂O₇/MWCNTs,另一种是将两者均匀混合掺杂得到La₂Mo₂O₇@MWCNTs,再将上述2种复合材料应用于染料敏化太阳能电池对电极进行相应研究。通过扫描电子显微镜（SEM）表征了复合催化材料的微观形貌,X射线衍射（XRD）确定了微观结构。采用电流密度-光电压曲线、循环伏安,交流阻抗以及塔菲尔极化分析了材料的光电性能。实验结果表明在电解液I₃^-/I^-中,基于La₂Mo₂O₇/MWCNTs与La₂Mo₂O₇@MWCNTs的对电极,相同的条件下在光电池中获得的光电转换效率分别为6.09%和4.84%,明显高于MWCNTs的3.94%和La₂Mo₂O₇的0.87%。电极性能的提高可归因于La₂Mo₂O₇复合催化剂相对大的比表面积和高导电性。更多还原

【Abstract】 A Pt-free counter electrode（CE）composed of La₂Mo₂O₇（La₂O₃-2MoO₂）was successfully synthesized via the simple pyrolysis of lanthanum acetate（C₆H₉O₆La·x H₂O）and hexaammonium heptamolybdate tetrahydrate(（NH₄）₆Mo₇O₂₄·4H₂O)in a high-temperature solid-state reaction.Also,La₂Mo₂O₇and multiwall carbon nanotubes（MWCNTs）are combined using two methods.La₂Mo₂O₇/MWCNTs was prepared by spray-coating La₂Mo₂O₇over the surface of MWCNTs,and La₂Mo₂O₇@MWCNTs was synthesized by doping La₂Mo₂O₇into MWCNTs.The two types of composite materials were further used as Pt-free catalytic material in CEs in dye sensitized solar cells（DSSCs）.The morphology and microstructure of La₂Mo₂O₇/MWCNTs and La₂Mo₂O₇@MWCNTs were determined using scanning electron microscopy and X-ray diffraction.The electrochemical performance of the La₂Mo₂O₇/MWCNTs and La₂Mo₂O₇@MWCNTs composite catalysts for CEs was determined using photocurrent-voltage measurements,cyclic voltammetry,electrochemical impedance spectroscopy,and Tafel polarization in encapsulation of DSSCs batteries.The experimental results show that power conversion efficiencies of 6.09%and4.84%were obtained for La₂Mo₂O₇/MWCNTs and La₂Mo₂O₇@MWCNTs,respectively,as CEs toward the reduction of I₃^-/I^-ions,and these values are superior to those of MWCNTs（3.94%）and the La₂Mo₂O₇（0.87%）electrode under the same conditions.The enhanced electrode performance was attributed to the relatively larger surface area and higher conductivity of the La₂Mo₂O₇/MWCNTs composite catalysts.更多还原