Bimetallic Nitride NiWN2/ Nitrogen-doped Reduced Graphene Oxide Nanocomposites as High-Performance Counter Electrode Materials for Dye-Sensitized Solar Cells

Abstract

Inspired by bimetallic sulfides and oxides, bimetallic nitride NiWN2/ Nitrogen-doped reduced graphene oxide (NiWN2/N-RGO) nanocomposites were prepared successfully through the hydrothermal method, and employed as high performance platinum-free counter electrodes (CEs) for dye-sensitized solar cells (DSCs). In the NiWN2/N-RGO CEs, NiWN2 nanoparticles were anchored on the surface of N-RGO. Benefiting from the synergistic effects of the high electrocatalytic activity from NiWN2 and the efficient electronic/ionic mixed conducting network provided by N-RGO, DSCs with NiWN2/N-RGO achieved an efficiency of 7.04%, which was up to 95% of that of a Pt CE (7.48%). Such an effective and versatile strategy may be extended to other bimetallic nitrides for use as inexpensive platinum-free CEs.