Interface-Engineered NiSe₂/1T-Phase-Rich MoS₂ Heterostructures for Enhanced Electrocatalytic Hydrogen Evolution

Constructing a heterojunction structure by combining two distinct two-dimensional materials with complementary properties represents a promising yet challenging approach to enhance the hydrogen evolution reaction (HER) in water electrolysis. So far, phase engineering has been extensively investigated and represents a highly effective strategy for enhancing the catalytic activity of non-noble-metal materials in various catalytic applications. This study demonstrates an in situ phase engineering strategy for MoS₂, where the metallic 1T-phase is synergistically enhanced through heterointerface coupling with NiSe. In addition, by further integrating density functional theory calculations, we elucidated the interfacial charge transfer dynamics governing the enhanced HER at the MoS₂-NiSe₂ heterointerface. The optimized MoS₂@NiSe₂/CC-2 electrocatalyst demonstrated exceptional performance metrics, requiring merely 98 mV overpotential to deliver a 10 mA cm^-2 current density, coupled with a favorable Tafel slope of 91 mV dec^-1. These findings establish a universal design principle for engineering high-efficiency HER electrocatalysts through precise interface modulation.