Sheet-like porous MoO₂/MoP nanoparticles as counter electrocatalysts for dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) with cheap, simple, and fast preparation methods have attracted great interest from researchers as outstanding representatives of third-generation solar cells. To improve the applicability of dye-sensitized solar cells, the development of materials with high efficiency and low production cost is the top priority. In this work, the MoO2/MoP heterostructure was obtained by a hydrothermal method combined with phosphate annealing, and their electrochemical properties were further investigated. Compared with MoO2, the heterogeneous MoO2/MoP possessed superior electrical conductivity and catalytic activity. The DSSC fabricated with MoO2/MoP achieved an excellent conversion efficiency (PCE) of 8.64%, which was better than that of MoO2 (7.63%), and platinum (7.68%). The results verified that the novel structural engineering and good synergy between MoO2 and MoP make it have excellent electrocatalytic behavior. Meanwhile, in the MoO2/MoP heterostructure, a large number of nanosheets are distributed on the porous MoO2. The porous structure enhances the ion penetration, and the abundant nanosheets expand the contact surface with the electrolyte, providing a substantial active reaction surface and sufficient catalytically active sites for the catalytic reduction of I-3(-). Therefore, the MoO2/MoP nanocomposites with high efficiency, simple preparation, and low cost provide a possibility for the study of electrode materials.