Template-free synthesis of Vanadium Nitride Nanopetals (VNNP) as a high performance counter electrode for dye sensitized solar cells

The thrust of finding an alternative and noble metal free counter electrode (CE) for dye sensitized solar cells (DSSCs) encouraged the present study on new and unique structure of vanadium nitride nanopetals as counter electrode for DSSCs. Template-free vanadium nitride nanopetals were successfully synthesized by high temperature ammonia treatment of the precursor material viz. V2O5/melamine. The material analysis reveals the formation of highly crystalline vanadium nitride with mesoporous crosslinked intertwined nanopetals with pronounced electrocatalytic active sites leading to an excellent catalytic performance towards iodide/triiodide electrolyte, fast charge transfer kinetics, electron diffusion and low charge transfer resistance. The fabricated dye sensitized solar cell sandwiched with N719 dye loaded photoanode and VN nanopetals CE with an injection of iodide/triiodide electrolyte showed a significant power conversion efficiency (PCE) of 7.44%, which is higher than Pt CE (7.38%) under the same testing conditions. Results thus proved that the material is a promising candidate as an alternative counter electrode for Pt in DSSC.