Cu/Cu2O Nanoparticle–Decorated MoO2 Nanoflowers as a Highly Efficient Electrocatalyst for Hydrogen Evolution Reaction

The development of highly efficient, economical, and sustainable electrocatalysts based on non-noble metals for hydrogen evolution reaction (HER) is of vital significance for large-scale renewable energy storage. Herein, an effective synthetic strategy for the construction of MoO 2 nanoflowers decorated with metallic Cu/Cu 2 O nanoparticles (NPs) on Ni foam (NF) (Cu 2 O/MoO 2 @Cu/NF) with a simple two-step method is reported. The prepared Cu 2 O/MoO 2 @Cu/NF as an electrocatalyst exhibits outstanding reactivity and remarkable stability in alkaline solution. The onset overpotential of Cu 2 O/MoO 2 @Cu/NF approaches 0 V. An overpotential as low as 32 mV is obtained to afford a current density of 10 mA cm −2 , comparable with Pt/C catalysts. The Tafel slope is low at 40 mV dec −1 as well. The involvement of zero-valent Cu greatly reduces the resistance. The well-dispersed Cu/Cu 2 O NPs on the sphere-like MoO 2 nanoflowers exaggerate the surface area. The ringent channels provide the fast release of evolved bubbles. Furthermore, the enhanced conductivity and large surface area lead to significant activity in HER. Herein, a novel design and facile synthesis of a highly efficient electrocatalyst with catalytic activity that is comparable to a Pt/C catalyst is provided.