One-step synthesis of self-supported porous NiSe2/Ni hybrid foam: An efficient 3D electrode for hydrogen evolution reaction

The search of cheap, earth-abundant and efficient hydrogen evolution reaction (HER) catalysts is significant for sustainable hydrogen economy. Here we introduce a simple and cost-effective strategy for one-step synthesis of 3D porous NiSe2/Ni hybrid catalysts from commercially available Ni foams via thermal selenization. This catalyst exhibits superior catalytic performance featured by a small overpotential (~143 mV) to afford 10 mA/cm2, small Tafel slope (49.0 mV/dec), large exchange current density (15.7 μA/cm2) and good stability in acid, which benefits from the good electrical conductivity of NiSe2 catalysts on Ni foam and the increase of additional porous structures at NiSe2 surface. This performance is superior to most of well-studied MoS2 or WS2-based catalysts, and the exchange current density is much larger than CoSe2 or MoS2-based catalysts. This achievement provides a straightforward and effective route to produce cheap and efficient catalysts from commercially available materials for large-scale water splitting.