Nitrogen‐Doped Graphene Nanosheets with FeN Core–Shell Nanoparticles as High‐Performance Counter Electrode Materials for Dye‐Sensitized Solar Cells

A newly designed counter electrode (CE) composed of a hybridized structure of iron nitride (FeN) core–shell nanoparticles grown on nitrogen‐doped graphene (NG) is presented for application in dye‐sensitized solar cells (DSSCs). The FeN core–shell nanoparticles on NG show an excellent electrocatalytic activity and lower charge‐transfer resistance (Rct) towards the CE (I−/I3−) redox reaction in DSSCs. The hybridized electrode exhibits remarkable cycling stability even after 500 cycles. The energy conversion efficiency of a DSSC cell with core–shell FeN/NG nanohybrids as the CE reaches 10.86%, which is superior to the energy conversion efficiency of 9.93% for a cell with a conventional Pt CE under the same experimental conditions. This work provides a novel approach to fabricate catalytically active electrodes for DSSCs and promotes the development of metal nitride‐based electrodes for photovoltaic applications.