Mesh Electrode with Regular Porous Structure for Hydrogen Production from Water Splitting by Promoting Gas Bubble Release

In order to promote gas bubble release during water splitting for hydrogen production, stacked mesh electrodes with regular porous structures have been fabricated by electrodepositing CoFe alloy. The average bubble size of 40 μm and release time of 2.11 s for hydrogen bubbles can be achieved during the process of water splitting at 50 mA cm-2 and 1 M KOH. The stacked mesh electrodes show excellent performance in both hydrogen evolution reaction (HER, 247 mV at 1000 mA cm-2) and oxygen evolution reaction (OER, 350 mV at 1000 mA cm-2). A cell voltage of 2 V can be achieved at 1000 mA cm-2 for flow-through electrolyzer assembled with the stacked mesh electrodes under the condition of 6 M KOH, and 343 K. The energy required for hydrogen production is only 4.04 kWh Nm-3 and 4.78 kWh Nm-3 under the current density of 200 mA cm-2 and 1000 mA cm-2, respectively. Besides, the flow-through electrolyzer assembled with the stacked mesh electrodes shows excellent stability with only a 60 mV increase in cell voltage after continuing electrolytic water splitting for 100 h at 1000 mA cm-2.