Flow-through porous electrode for enhanced oxygen evolution reaction by promoting gas bubble release from water splitting

Several CoS 2 /Ni flow-through porous electrodes are fabricated to promote gas bubble release for enhanced oxygen evolution reaction. Structural characterization shows that CoS 2 catalyst is immobilized on the porous Ni substrate. The bubble average diameter can be decreased from 29.21 ± 17.9 μm to 13.38 ± 5.05 μm, and the desorption time is decreased from 1.615 s to 0.067 s, with the electrolyte velocity increasing from 0 cm/s to 2.89 cm/s at the current density of 100 mA/cm 2 . A mathematical model is proposed to describe gas bubble growth, which is found that higher current density is not bring much bigger gas bubble. The overpotential of the CoS 2 /Ni electrode for OER is 498 mV at 100 mA/cm 2 . The overpotential of CoS 2 /Ni electrode can be decreased from 754 mV to 661 mV with the electrolyte velocity increase from 0 cm/s to 9.42 cm/s at 200 mA/cm 2 with the energy required for hydrogen production reduced by 5.01 kWh/kmol.