(211d) Efficient Strategies to Accelerate Anodic Reactions in Electrolysis Systems for Hydrogen Production

Electrochemical water splitting is an economical and green approach to producing clean hydrogen, a promising technology to alleviate the energy crisis. A high operating cell voltage is needed to achieve the desired current density due to the sluggish kinetics of oxygen evolution reaction (OER). Herein, we demonstrated two strategies to improve the OER activity of the cobalt-nickel sulfides on Ni foam (Co-S/Ni3S2@NF): adding glycerol and increasing the temperature. A current density of 20 mA cm^-2 could be reached at an extremely low potential of 1.35 V (vs. RHE) by adding 0.1 M glycerol to the alkaline electrolyte, indicating glycerol oxidation reaction (GOR) is a possible anodic reaction to replace the sluggish OER. The estimated activation energy of Co-S/Ni3S2@NF for OER is higher than that for GOR, indicating the OER process with high kinetic energy barriers. By adding glycerol and increasing the temperature, the anodic current density at ~1.6 V was observed to increase tenfold, providing solutions to improve electrolysis efficiency. These findings provide valuable clues to overcoming the sluggish kinetics of the anodic reaction process and improving electrolysis efficiency.