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

In recent years, electro- or photoelectrochemical water splitting represents a promising route for renewable hydrogen generations but still requires the substantial development of efficient and cost-effective catalysts to further reduce the energy losses and material costs for scalable and practical applications. Here, we report the design and development of a hierarchical electrocatalyst constructed from microporous nickel foam and well-assembled bimetallic nickel-molybdenum (NiMo) nanowires, which are capable to deliver current densities as comparable to those of the state-of-the-art Pt/C catalyst at low overpotentials and even larger current densities at higher overpotentials ( > 124 mV). This binder-free 3D hydrogen evolution cathode catalyst also exhibits the excellent stability, without any decay of the current density observed after long-term stability tests at a low current density of 10 mA cm(-2) and a high current density of 50 mA cm(-2). By pairing this NiMo 3D cathode with a NiFe-based anode, a water electrolyzer can be achieved with a stable current density of 10 mA cm(-2) for overall water splitting at a voltage of similar to 1.53 V, indicating that the water splitting can be indeed realized without any performance sacrifice by using earth abundant electrocatalysts. (C) 2016 Elsevier Ltd. All rights reserved.