Facile coordination driven synthesis of metal-organic gels toward efficiently electrocatalytic overall water splitting

A series of MOGs were prepared for high-efficiency electrocatalytic overall water splitting. The Ni0.6Fe0.4 MOG exhibited the highest electrocatalytic activity. [Display omitted] •An ultral-simple and ecofriendly method to synthesize a series of metal-organic-gels (MOGs) were adopted.•Unique 3D nanofiber network structure.•Extensive and systematic exploration of MOGs for electrocatalytic overall water splitting. The coordination driven self-assembled materials are in high demand of advanced energy chemistry, which remain largely unexplored. Here an ultra-simple and environmental friendly strategy for fabricating metal-organic gels (MOGs) in terms of electrochemical overall water splitting was reported. Through electrochemical testing, the Ni0.6Fe0.4-MOG achieves the lowest oxygen evolution reaction (OER) overpotential of 285 mV (j10), 347 mV (j100), 445 mV (j500) (GC electrode) and 173 mV (j10, NF electrode) in 1 M KOH, an ultra-low Tafel slope of 33 mV dec−1 and long-term stability, outperforming most of the reported polymer catalysts. On account of the moderate hydrogen evolution reaction (HER) performance (159 mV (j10)), thereby can drive the two-electrode electrolyzer at a relatively low cell voltage of 1.61 V (1.48 V when using Pt/C as cathode) and no significant attenuation after 20 h. Our work has demonstrated that the MOGs could break the shackles of current polymer catalysts for electrocatalysis.