Nickel hydroxide electrode with a monolayer of nanocup arrays as an effective electrocatalyst for enhanced electrolysis of urea

Nickel hydroxide electrode composed of cup-like pore arrays, which could act as an effective catalyst layer for electrolysis of urea, was formed on stainless steel foil by cathodic electrodeposition using a monolayer of polystyrene spheres as a template. The morphology of the catalyst layer could be controlled from nanocup to hollow sphere by tuning the deposition time. Electrolysis of urea was characterized by cyclic voltammetry and chronoamperometry in 1 M KOH electrolyte containing 0.33 M urea. The tailored catalyst layer with nanocup arrays expedited the transport of ion, electron, and gas. Moreover, cup-like pore arrays might lead to an increased surface area, and more active sites were exposed to electrolyte for the electrolysis of urea. Therefore, the nickel hydroxide electrode with nanocup architecture offered the benefit of much better electrocatalytic performance than the film electrode and hollow-sphere electrode during electrolysis of urea.