Electrochemically Induced Ru/CoOOH Synergistic Catalyst as Bifunctional Electrode Materials for Alkaline Overall Water Splitting.

ABSTRACT

Efficient and affordable price bifunctional electrocatalysts based on transition metal oxides for oxygen and hydrogen evolution reactions have a balanced efficiency, but it remains a significant challenge to control their activity and durability. Herein, a trace Ru (0.74 wt.%) decorated ultrathin CoOOH nanosheets (≈4 nm) supported on the surface of nickel foam (Ru/CoOOH@NF) is rationally designed via an electrochemically induced strategy to effectively drive the electrolysis of alkaline overall water splitting. The as-synthesized Ru/CoOOH@NF electrocatalysts integrate the advantages of a large number of different HER (Ru nanoclusters) and OER (CoOOH nanosheets) active sites as well as strong in-suit structure stability, thereby exhibiting exceptional catalytic activity. In particular, the ultra-low overpotential of the HER (36 mV) and the OER (264 mV) are implemented to achieve 10 mA cm-2. Experimental and theoretical calculations also reveal that Ru/CoOOH@NF possesses high intrinsic conductivity, which facilitates electron release from H2O and H-OH bond breakage and accelerates electron/mass transfer by regulating the charge distribution. This work provides a new avenue for the rational design of low-cost and high-activity bifunctional electrocatalysts for large-scale water-splitting technology and expects to help contribute to the creation of various hybrid electrocatalysts.