Ru-decorated cobalt-iron oxide nanosheet arrays derived from MOF and LDH double-precursors for overall water splitting in alkali and seawater

Exploring low-cost and highly efficient bifunctional electrocatalysts for electrochemical water splitting is crucial for developing sustainable energy systems. Hence, Ru-decorated cobalt-iron oxide nanosheet arrays derived from the metal-organic framework (MOF) and layered double hydroxide (LDH) double precursors on nickel foam (NF) was developed for the first time. It is found that the introduction of MOF and LDH double precursors can optimize the morphology of the nanosheets for increasing the electrochemically active surface area and reactive sites. Meanwhile, the modulation of Ru facilitates the electronic structure regulation in the catalytic process of Ru-CoFe2O4/NF, with low overpotentials of 253 and 87 mV at a current density of 100 mA cm−2 for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in alkaline freshwater media, respectively. Moreover, Ru-CoFe2O4/NF || Ru-CoFe2O4/NF exhibits excellent performance for overall water splitting in alkaline freshwater and seawater media. This work proposes an exciting prospect for the facile fabrication of cost-effective electrocatalysts that enhance hydrogen production in electrocatalytic water and seawater electrolysis.