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The development of advanced earth-abundant electrocatalysts for hydrogen production is highly desirable. In this paper, we report the design and synthesis of a novel and highly efficient electrode of NiCo2O4 nanoneedles decorated with FeCoNi layered ternary hydroxides supported on carbon cloth (FeCoNi-LTH/NiCo2O4/CC) by a facile and efficient two-step approach. It exhibits superior bifunctional catalytic activities for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media, due to the special structure and strong synergies. The FeCoNi-LTH/NiCo2O4/CC obtains an onset overpotential of 240 mV and an overpotential of 302 mV at the current density of 50 mA cm–2 for OER, which is superior to RuO2. It also efficiently catalyzes HER with onset overpotential of 96 mV and overpotential of 151 mV to achieve a current density of 20 mA cm–2. Serving as both cathode and anode in a two-electrode water splitting system, FeCoNi-LTH/NiCo2O4/CC only requires an overpotential of 1.65 V at current density of 50 mA cm–2. The cell exhibits outstanding stability as well, indicating that FeCoNi-LTH/NiCo2O4/CC is a befitting material to be utilized as effective bifunctional catalysts for overall water splitting.

The development of efficient, low-cost, and stable electrocatalysts for overall water splitting is of great significance for energy conversion. Transition-metal carbides (TMCs) with high catalytic activity and low cost have attracted great interests. Nevertheless, utilizing an efficient catalyst for overall water splitting is still a challenging issue for TMCs. Herein, we report the synthesis of a high-performance electrocatalyst comprising CoZnC and Co nanoparticles embedded in a nitrogen-doped carbon nanotube-grafted carbon polyhedral (CoZnC/Co-NCCP) by the pyrolysis of bimetallic zeolitic imidazolate frameworks in a reductive atmosphere of Ar/H. The CoZnC/Co-NCCP exhibits remarkable electrochemical activity in catalyzing both the oxygen evolution reaction and hydrogen evolution reaction, in terms of low overpotential and excellent stability. Furthermore, the CoZnC/Co-NCCP catalyst leads to a highly performed overall water splitting in the 1 M KOH electrolyte, delivering a current density of 10 mA cm at a low applied external potential of 1.65 V and shows good stability without obvious deactivation after 10 h operation. The present strategy opens a new avenue to the design of efficient electrocatalysts in electrochemical applications.

Green biomass derived three-dimensional interconnected porous carbon skeletons with in situ decorated IrCo nanoparticles were fabricated for high-performance Li–O2 batteries.