2D MOF-derived porous NiCoSe nanosheet arrays on Ni foam for overall water splitting

The exploitation of low-cost, efficient and stable electrocatalysts for overall water splitting in alkaline media is critical for future renewable energy systems, yet still remains a great challenge. Herein, we report the in situ growth of porous NiCoSe nanosheet arrays derived from 2D MOFs on Ni foam through a simple ion-exchange reaction followed by a hydrothermal process. Benefiting from the unique 2D multi-porous framework with high electrochemical active surface area, conductivity and open channels for the release of gaseous products, the as-prepared NiCoSe nanosheet arrays exhibit excellent electrochemical activity with a low overpotential of 170 mV for the hydrogen evolution reaction (HER) at 10 mA cm(-2) and 278 mV for the oxygen evolution reaction (OER) at 20 mA cm(-2) and long-term stability. Furthermore, the full cell only requires 1.51 V to drive the current density of 10 mA cm(-2) when the NiCoSe nanosheet arrays are used as both anode and cathode, which also exhibits distinguished durability for over 48 h. The present work presents a general strategy for the rational design and synthesis of multifunctional 2D porous electrocatalysts, which is also expected to extend to other noble-metal-free catalysts.

Automated summary

The study presents a general strategy for the rational design and synthesis of multifunctional 2D porous electrocatalysts, demonstrating excellent electrochemical activity and long-term stability in overall water splitting applications. The porous NiCoSe nanosheet arrays show low overpotential for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), making them promising candidates for future renewable energy systems.