Sulfur Recovery Assisted Electrochemical Water Splitting for H₂ Production Using CoMo-Based Nanorod Arrays Catalysts

Abstract

Swapping the sluggish oxygen evolution reaction (OER) for the thermodynamically advantageous sulfur ion oxidation reaction (SOR) makes it possible to produce lowenergy hydrogen. We report here on an electrocatalytic SORcoupled HER system that allows for the joint production of sulfur and hydrogen. We prepare a CoMoO 4 nanoarray on nickel foam (NF) for anodic SOR and N-doped CoMoO 4 /NF, CoMoN/NF, for cathodic HER. The current density of 100 mA cm −2 was obtained at 0.29 V (vs RHE) in the SOR process. After nitridation, the electrode can achieve a current density of 10 mA cm −2 in HER at a voltage of only 32 mV (vs RHE). The coupling system (SOR//HER) can run steadily for 150 h. Detailed exploration and discussion were conducted on the pathways of SOR. This work develops an energy-efficient mixed water electrolysis system for H 2 , providing a viable option for toxic waste treatment.