Multi-active site CoNi-MOFs as non-noble bifunctional electrocatalysts for highly efficient overall water splitting

The high-efficiency non-precious metal catalysts for oxygen evolution (OER) and hydrogen evolution (HER) are of great significance to the development of renewable energy technologies. Herein, a multiple active sites CoNi-MOFs-DBD electrocatalyst modified by low temperature plasma (DBD) was successfully synthesized by converting metal hydroxyfluoride on nickel foam into a well-arranged MOFs array using vapor deposition. The as prepared CoNi-MOFs-DBD electrode showed better HER and OER catalytic activity, super hydrophilicity, and excellent stability. In an alkaline medium, the overpotential of HER is 203 mV at 10 mA cm(-2) and that of OER is 168 mV at 40 mA cm(-2). When CoNi-MOFs-DBD was used as a bifunctional electrocatalyst for overall water splitting in a two-electrode system, a current density of 10 mA cm(-2) can be achieved at a low voltage of 1.42 V, which shows great potential in electrocatalytic water splitting. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A high-efficiency CoNi-MOFs-DBD electrocatalyst modified by low temperature plasma was successfully synthesized, showing excellent HER and OER catalytic activity as well as stability. With great performance in electrocatalytic water splitting in an alkaline medium, it demonstrates significant potential in the field of catalytic water splitting.