Nitrogen-doped carbon encapsulating γ-MoC/Ni nanoparticles as efficient counter electrodes for dye-sensitized solar cells

Abstract

The counter electrode (CE) is a crucial part in dye-sensitized solar cells (DSSCs). By catalyzing the reduction of the oxidized state to the reduced state for a redox couple (e.g. I3 −/I−) in electrolyte, the CE fulfills the vital role of completing the electric circuit. Developing efficient and economical electrocatalytic materials to replace the traditional platinum (Pt) CE has attracted attention. In the present study, γ-MoC/Ni@NC material was used as a CE in DSSCs for the first time. This material was synthesized by solid-state pyrolysis of related compounds of molybdate, oxalate, melamine and nickel salts. The DSSC with this composite catalyst achieves power conversion efficiency (PCE) of 5.26%, which is equivalent to the one based on the traditional Pt CE (5.65%). Although the PCE of DSSC based on γ-MoC/Ni@NC is slightly lower than that of Pt, the synthesis method is simple and cost-effective. This study paves the way for further development of highly active, simple processing, inexpensive CE materials in DSSCs.