In situ Formed Co(TCNQ)₂ Metal-Organic Framework Array as a High-Efficiency Catalyst for Oxygen Evolution Reactions

Energy conversion and storage systems such as water splitting devices and metal-air batteries need excellent and energy-efficiency oxygen evolution reaction (OER) catalysts. This work reports the in situ development of sawtooth-like Co(TCNQ)₂ (TCNQ=tetracyanoquinodimethane) metal-organic framework array on Co foil (Co(TCNQ)₂ /Co) by means of a solution immersion method at room temperature. As an oxygen-evolving catalyst, the resulting Co(TCNQ)₂ /Co demonstrates superior OER activity with overpotential of 310 mV to drive a geometrical catalytic current density of 15 mA cm^-2 in 1.0 M KOH. Notably, it also shows good long-term electrochemical durability with its activity being retained for at least 20 h and achieves a high turnover frequency of 0.66 mol O₂ s^-1 at overpotential of 380 mV.