A dye-sensitized solar cells with an efficiency of 10.01% based on the MoP/MoNiP2@Ti3C2 composite counter electrode

Transition metal phosphides are becoming a main study topic in new catalytic materials field due to their similar properties to transition metal nitrides and carbides as well as their excellent reaction activity and catalytic selectivity for deep hydrodesulfurization and hydrodenitrogenation. Mxene, a two-dimensional layered material with high specific surface area and electrical conductivity, plays an important role in accelerating catalytic reduction of triiodide ion in dye-sensitized solar cells (DSSCs). In this work, the MoP/MoNiP2 hybrid was synthesized while adopting Ti3C2 Mxene to realize the intercalation structure of composite with simple conditions, therefore enabling a formation of ‘pillared effect’ in Ti3C2 Mxene. The optimized MoP/MoNiP2@Ti3C2 composite was achieved by adjusting the doping ratio of the two. The DSSCs based on the MoP/MoNiP2@Ti3C2 catalyst with 80 wt% Ti3C2 doping reache an enhancement of power conversion efficiency of 10.01%, much higher than that of the platinum counter electrode (8.22%). Through a suite of morphological and electrochemical analyses, we summarize the reasons for the performance enhancement to the synergistic effect of the MoP/MoNiP2 hybrid and Ti3C2 Mxene, and especially, the unique intercalation structure of MoP/MoNiP2@Ti3C2 with ‘pillared effect’. The MoP/MoNiP2@Ti3C2 counter electrode with perfect electrochemical and photoelectrochemical properties is a promising alternative to the platinum electrode for DSSCs in the future.