RuSe₂-CoTe Heterogeneous Surfaces Coated with NC Layer for Excellent HER Performance under Alkaline Condition

Electrocatalytic hydrogen production has been a promising high-purity hydrogen production technology, attracting a large number of researchers' research interest. Ru has a hydrogen binding capacity similar to Pt, but its price is far lower than Pt, making it a promising alternative to Pt. However, a single Se electronic structure modulation is not sufficient to enable RuSe₂ to be used for practical applications on a large scale due to the lack of electrons. Therefore, choosing a suitable way to electronically modulate the Ru atoms in RuSe₂ can effectively improve the activity of the catalyst. Cobalt telluride (CoTe) can significantly enhance electrocatalytic performance due to tellurium's low electronegativity and excellent metal properties. In this work, the NC layer possesses excellent electrical conductivity and CoTe acts as an electron donor to optimize the electronic structure locally and trigger electron transfer efficiently. The RuSe₂-CoTe/NC electrode requires an overpotential of only 25.4 mV (10 mA cm^-2), which is superior to that of RuSe₂/NF (65 mV) and CoTe/NC (115 mV). Meanwhile, the Tafel slope of RuSe₂-CoTe/NC (67.8 mV dec^-1) was better than that of RuSe₂/NF (113.6 mV dec^-1) and CoTe/NC (209.5 mV dec^-1), showing that the build-up of the superior heterojunction makes the RuSe₂-CoTe/NC with better hydrogen evolution reaction (HER) reaction kinetics. In addition, after 30 h of long-term stability testing, no significant decrease in catalytic activity was observed, proving the good stability of the RuSe₂-CoTe/NC catalyst.