Efficient wide-spectrum dye-sensitized solar cell by plasmonic TiN@Ni-MXene as electrocatalyst

Herein, dispersed Ni species over the surface of plasmonic TiN nanocrystals (TiN@Ni) are manufactured by using wetness impregnation method. This developmental material holds abundant surface sites and local surface plasmon resonance property. To further satisfy the requirement as the electrocatalyst for dye-sensitized solar cell (DSSC), bifunctional TiN@Ni nanocrystals are incorporated with monolayer MXene to construct the continuous conductive matrix. The yielded TiN@Ni-MXene film serves as counter electrode, power conversion efficiency(PCE) of corresponding DSSC under conventional irradiation condition is 8.08%, which surpasses as-reference Pt-based DSSC(7.59%). When further adding the NIR irradiation from counter electrode side of device, DSSC achieves an impressive PCE of 8.45%. The superior performance of TiN@Ni-MXene electrode should be attributed to the created active sites on the surface of TiN support, and the plasmonic effect from TiN@Ni nanoparticles via utilizing NIR light. Ni species provide more adsorption sites for triiodide ions, meanwhile the elevated temperature from plasmon-induced photothermal effect can effectively boost the triiodide reducing reaction rates at the interface of electrode and electrolyte. Thus electrocatalytic performance of TiN@Ni-MXene counter electrode is remarkablely enhanced. The strategy here will be beneficial for the design of highly active and stable electrocatalyst for DSSC, as well as realizing the efficient utilization for wide-spectrum solar energy.