Nickel-based 3D electrocatalyst layers for production of hydrogen by water electrolysis in an acidic medium

Electrocatalytic activity of three-dimensional nickel-based layers in the hydrogen evolution reaction (HER) was investigated in an acidic medium. It was demonstrated that patterning of a glassy carbon electrode substrate with a 3D polyaniline (PANI) matrix is a convenient way of increasing the electrocatalytically active surface area of electrodeposited Ni, and hence its apparent electrocatalytic activity. The optimized PANI/Ni electrocatalyst layer showed a significantly higher activity in the HER then a two-dimensional control Ni-plate surface. It was also demonstrated that it is possible to produce a Ni-based HER electrocatalyst layer by synthesizing Ni nanoparticles and supporting them on Vulcan carbon. This electrocatalyst also offered a significantly higher electrocatalytic activity in the HER then the control surface, but lower then the optimized PANI/Ni electrocatalyst. The electrocatalytic activity of the optimized PANI/Ni layer was also compared to the activity of a 3D catalyst produced by coating a porous RVC cube substrate with Ni. This electrocatalyst showed the highest HER electrocatalytic activity among the investigated layers when tested under potentiodynamic polarization conditions. However, under the potentiostatic conditions, the optimized PANI/Ni layer showed the highest electrocatalytic activity.