Constructing NiSe₂/MoSe₂ Mott-Schottky Heterojunctions Onto N-doped Brain Coral-Carbon Spheres by Phase Separation Strategies for Advanced Energy Conversion Applications

Constructing Mott-Schottky heterojunctions in nanohybrids is an effective strategy for facilitating electron transfer and optimizing the electronic structure of active sites; however, challenges remain. Herein, a selenium-induced phase separation strategy is proposed and successfully construct NiSe2/MoSe2 Mott-Schottky heterojunctions on N-doped brain coral carbon nanospheres (N-BCCSs). Owing to built-in electric fields, optimized electronic density, and unique nanoflake/sphere structures, the designed NiSe2/MoSe2@N-BCCSs carbon-based Mott-Schottky catalysts achieved satisfactory electrocatalytic performance. When serving as a counter electrode for the triiodide reduction reaction (IRR), a power conversion efficiency of 8.49% is obtained, which outperformed that of conventional Pt electrodes (7.80%). When the NiSe2/MoSe2@N-BCCSs are used as electrocatalysts for the hydrogen evolution reaction (HER), their overpotential (eta(10)) is as low as 119 mV, which is significantly better than that of other transition-metal selenides. This research demonstrates a new concept for constructing Mott-Schottky heterojunctions and provides a new direction for investigating multifunctional carbon-based composites.