In recent years, electro- or photoelectro-chemical water splitting has represented a promising route for renewable hydrogen generations; however, it still requires the substantial development  of  efficient  and  cost-effective  catalysts  in  order  to  further  reduce  the  energy losses  and  material  costs  for  scalable  and  practical  applications. Here, for the first time, we report the design and development of hierarchical electrocatalysts constructed from low-cost microporous nickel foam and well-assembled bimetallic nickel-molybdenum (NiMo) nanowires. Benefited from the high intrinsic activity of the NiMo alloy and the unique hierarchical architecture, our NiMo-NWs/Ni-foam catalyst has exhibited an unprecedented high catalytic activity for hydrogen evolution in alkaline solutions, being capable to deliver current densities as comparable or even superior to that of the state-of-the-art Pt/C catalyst in the same conditions. Also, this binder-free 3D hydrogen evolution cathode catalyst exhibits the excellent stability, without any performance decay observed after long-term stability tests at different current densities. More importantly, by pairing this NiMo/Ni foam 3D cathode with a NiFe-based anode, a water electrolyzer can be achieved with stable current densities for the overall water splitting at a potential of ~1.53 V, indicating that the water splitting can be indeed realized without any performance sacrifice by using earth abundant electrocatalysts. All these results have evidently designated that our hierarchical NiMo-NWs/Ni-foam catalysts can be advantageously utilized in alkaline water electrolysis to drive the water splitting reaction efficiently at a significant rate at ultralow overpotentials.

Hierarchical NiMo-based 3D electrocatalysts for highly-efficient hydrogen evolution in alkaline conditions

253rd National Meeting (2017)

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