Microporous structure flowing integrated with electrolytic water splitting based on stacked mesh electrode for hydrogen production

Abstract

In order to promote gas bubble transport during water splitting for hydrogen production, stacked mesh electrodes integrated microporous structure flowing and electrolytic water splitting have been fabricated by electrodepositing CoFe alloy. The average size of the bubble on the mesh electrode surface is 40 μm and the release time of trapped bubbles in the pores of the electrode is 2.11 s during the process of water splitting at 50 mA cm−2 and 1 M KOH. The 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). The required cell voltage at 1000 mA cm−2 for flow-through electrolyzer assembled with the stacked mesh electrodes is only 2 V under the condition of 6 M KOH, and 343 K. The voltage caused by the bubble in the flow-through electrolyzer assembled with stacked mesh electrodes is just about 50 mV at the current density of 1000 mA cm−2. 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.