Heterointerface‐Driven Electronic Modulation in MoO₂@N/Mo‒ReS₂ Hybrid for Efficient Alkaline HER, OER, and Overall Water Splitting

Abstract

Alkaline water electrolysis is an efficient technical pathway for producing high-purity green hydrogen (H₂). However, rational design and fabrication of efficient electrocatalysts are essential for energy conversion. Herein, MoO₂ nanoclusters on N/Mo dual-doped ReS₂ nanosheets (MoO₂@N/Mo-ReS₂) develops through a hydrothermal and CVD-nitridation process. This novel strategy leads to modifying the electronic properties of metastable ReS₂ through metal/nonmetal doping, heterostructure formation, and basal plane activation, thus increasing the number of electrochemically active sites. The MoO₂@N/Mo-ReS₂ catalyst is effective at hydrogen-adsorption, has a low energy barrier for water dissociation, and exhibits high electrical conductivity, as demonstrated by density functional theory (DFT) studies. The optimal MoO₂@N/Mo-ReS₂ heterostructure shows exceptional endurance at low overpotentials of -93 and 249 mV, respectively, and catalytic activity for the evolution of both H₂ and oxygen (O₂) at a current density of 10 mA cm^-2 in an alkaline electrolyte. The performance of the MoO₂@N/Mo-ReS₂ electrolyzer is 1.54 V at 10 mA cm^-2, which is comparable to a commercial Pt/C||RuO₂ (1.56 V at 10 mA cm^-2) electrocatalyst. This study offers a promising strategy for the development of scalable and efficient electrocatalysts, aiming to enhance their suitability for energy applications.