Enhancement of the triiodide reduction reaction by doping molybdenum in NiSe hierarchical microspheres: a theoretical and experimental study

Abstract

Heterogeneous metal atom doping is considered as an effective strategy to boost catalytic activity through the coordinated modulation of metal active sites and the electronic structure, which is also beneficial for establishing the relationship between structure and performance in energy conversion devices. Herein, we developed Mo-doped NiSe hierarchical microspheres with different Mo doping amounts by a simple solvothermal method. DFT calculation results including the more appropriate adsorption energy for adsorption of I₃⁻, the further elongated I₁–I₂ bond length of I₃⁻, and efficient interaction between metal 3d and I 5p states collectively indicated that the catalytic activity for the IRR can be significantly enhanced by doping molybdenum in NiSe. Subsequently, dye-sensitized solar cells (DSSCs) fabricated with the optimized Mo_0.10–NiSe display a remarkable power conversion efficiency of 8.92%, superior to that of the Mo_0.05–NiSe (8.40%), Mo_0.15–NiSe (8.62%), NiSe (7.51%), and Pt-based devices (7.74%) in comparison. The impressive performance endows Mo_0.10–NiSe with a new opportunity to achieve the substitution of noble Pt in low-cost DSSCs.