MoSe₂-Ni₃Se₄ Hybrid Nanoelectrocatalysts and Their Enhanced Electrocatalytic Activity for Hydrogen Evolution Reaction

Combining MoSe₂ with other transition metal dichalcogenides to form a hybrid nanostructure is an effective route to enhance the electrocatalytic activities for hydrogen evolution reaction (HER). In this study, MoSe₂-Ni₃Se₄ hybrid nanoelectrocatalysts with a flower-like morphology are synthesized by a seed-induced solution approach. Instead of independently nucleating to form separate nanocrystals, the Ni₃Se₄ component tends to nucleate and grow on the surfaces of ultrathin nanoflakes of MoSe₂ to form a hybrid nanostructure. MoSe₂-Ni₃Se₄ hybrid nanoelectrocatalysts with different Mo:Ni ratios are prepared and their HER catalytic activities are compared. The results show that the HER activities are affected by the Mo:Ni ratios. In comparison with pure MoSe₂, the MoSe₂-Ni₃Se₄ hybrid nanoelectrocatalysts having a Mo:Ni molar ratio of 2:1 exhibit enhanced HER properties with an overpotential of 203 mV at 10 mA/cm² and a Tafel slope of 57 mV per decade. Improved conductivity and increased turnover frequencies (TOFs) are also observed for the MoSe₂-Ni₃Se₄ hybrid samples.