In order to study the effect of nickel powder morphology on the hydrogen evolution performance of prepared aligned porous electrodes, both spherical and flake nickel powder are used in the electrode preparation. Experimental results show that the aligned porous electrode prepared by spherical nickel powder exhibit a larger electrochemically active surface area, demonstrating superior hydrogen evolution performance at low current density. Conversely, the aligned porous electrode prepared by flake nickel powder demonstrates higher bubble transfer efficiency and better hydrogen evolution performance at high current density. Furthermore, the influence of electrode thickness on the hydrogen evolution performance are studied. For the aligned porous electrode prepared using spherical nickel powder, increasing the thickness to 600 Î¼m initially enhances electrode performance, but it subsequently decreases with further increases in current density. On the other hand, the aligned porous electrode prepared using flake nickel powder exhibits improved performance within the tested range as the electrode thickness is increased to 600 Î¼m.
Keywords Hydrogen Evolution Reaction, freeze casting, aligned porous electrode, bubble removal