本文以碳纳米管（CNTs）与Ni₂P纳米晶制备CNTs-Ni₂P复合材料，首次研究其染料敏化太阳能电池（DSSCs）的光阴极材料性能. 采用X射线衍射（XRD）和透射电子显微镜（TEM）测定材料结构和观察其形貌. 结果表明，复合材料由碳纳米管和六方结构的磷化镍构成，无其它磷化物杂相，磷化镍纳米晶（10 nm左右）分散于CNTs表面. 交流阻抗（EIS）测试显示，与CNTs和Ni2P对电极相比，CNTs-Ni2P对电极的电荷转移电阻和扩散阻抗较低，接近Pt-FTO对电极水平. CNTs-Ni₂P对电极的DSSCs光电流达12.9 mA.cm^-2，能量转化效率达5.6 %，接近Pt-FTO对电极的DSSCs能量转化效率（5.9 %）. 这归因于高电催化活性的磷化镍纳米晶与高电导CNTs的协同效应.

Carbon nanotubes (CNTs) supported by Ni₂P nanoparticles are prepared and used as a counter electrode in dye-sensitized solar cells (DSSCs) for the first time. The CNTs-Ni₂P composite was prepared by the heat treatment of a mixed precursor including nickel chloride, sodium hypophosphite and CNTs in argon atmosphere. The X-Ray diffraction (XRD) results indicate that the as-prepared sample consists of hexagonal Ni2P and carbon nanotubes. No peaks of other nickel phosphides are observed in the XRD pattern. Microstructure of the Ni₂P-CNTs composite was investigated using transmission electron microscopy (TEM). It is shown that the Ni₂P nanoparticles with a size of about 10 nm are dispersed on the surface of CNTs. In addition, electrochemical impedance spectra (EIS) and photovoltaic conversion performance of counter electrodes for DSSCs are analyzed in detail. It is demonstrated that the Ni2P-CNTs composite presents an obviously low charge-transfer resistance and diffusion impedance as compared with those of individual CNTs and Ni₂P. Accordingly, the DSSCs using the composite as a counter electrode have a comparable photovoltaic performance as compared with the conventional FTO/Pt counter electrode, due to the effective combination of the high electrical conductivity of carbon nanotubes and superior electrocatalytic activity of Ni₂P nanoparticles.