Ni(OH)2/ NiSe2 hybrid nanosheet arrays for enhanced alkaline hydrogen evolution reaction

Abstract Developing efficient, non-noble electrocatalysts toward hydrogen evolution reaction (HER) in alkaline electrolytes is of important significance for future energy supplement but still a challenge. Recently, pyrite-type NiSe2 nanomaterial has been considered as an idea HER electrocatalyst due to its high conductivity, strong corrosion resistance and low cost. However, the HER performance of NiSe2 in alkaline electrolytes is still unsatisfactory, which is possibly limited to the activate water dissociation in alkaline media. Herein, a novel hybrid electrocatalyst of Ni(OH)2/NiSe2 nanosheet arrays on carbon cloth (Ni(OH)2/NiSe2/CC) is fabricated, exhibiting excellent HER catalytic activity with a low overpotential of 82 mV to drive a current density of 10 mAcm−2 as well as maintaining a long-term durability for 12 h in 1.0 M KOH, which is 77 mV less than that of NiSe2/CC and superior to most recently reported non-noble HER electrocatalysts. In addition, the Tafel slope of Ni(OH)2/NiSe2/CC (60 mV dec −1) is also much smaller than that of NiSe2/CC (112 mV dec −1), suggesting a promotion kinetics of HER process for Ni(OH)2/NiSe2/CC. Our further experimental results show that the significantly improved activity of Ni(OH)2/NiSe2/CC electrode should ascribe to its enlarged active surface, good conductivity and interfacial synergy between Ni(OH)2 and NiSe2. The synergetic strategy may provide an efficient way to promote the HER activity of other non-noble transition metal selenides in alkaline electrolyte.