Effect of aligned porous electrode thickness and pore size on bubble removal capability and hydrogen evolution reaction performance

Aligned porous electrodes with different pore sizes and thicknesses are prepared by freezing casting method, and the effect of the electrode thickness and pore size on hydrogen evolution reaction (HER) performance and bubble removal capability are experimentally studied. The results show that the pore size and thickness of the aligned porous electrodes have a significant impact on the HER performance by affecting the electrochemical active surface area (ECSA) and bubble transport process. The influence of pore sizes and electrode thicknesses on HER performance are different with current density. In the region of low current density, the effect of electrode thickness on electrochemical performance is more significant than that of pore size. While at high current density pore size becomes a limiting factor for electrochemical performance. Additionally, the Δζγ is proposed to evaluate the bubble removal capability, and a small Δζγ indicates the good bubble removal efficiency.