One step fabrication of nanostructured nickel thin films on porous nickel foam for drastic electrocatalytic oxygen evolution

The oxygen evolution reaction (OER) is crucial for sustainable hydrogen production through competitive water electrocatalysis. In this work, nanostructured nickel (Ni) thin films deposited on porous nickel foam (NF) substrate are investigated for improved OER catalysis in alkaline medium. The time-dependent fabrication of Ni thin films is achieved via aerosol-assisted chemical vapor deposition (AACVD), which has shown promising impact on the OER performance. Particularly, the nanoscale Ni@NF electrocatalyst after 60-min of deposition showed outstanding OER properties including minimum overpotential of 285 and 423 mV to reach the current decade (10 mAcm⁻²) and even higher than 1000 mA/cm², respectively. The electrode exhibits a small Tafel slope with a value of 70 mV dec⁻¹, a higher TOF, a large electrochemically active surface area, better charge transport performance, and long-term stability over 20 h of continuous operation without significant loss. This OER catalytic activity for pristine Ni electrocatalysts is a significant milestone and is found much better than the benchmark noble metal OER catalysts as well as many other well-known 3D transition metal catalysts. The impressive OER performance is attributed to the synergic effect generated between nanostructured-Ni and porous NF substrate, which enhances the electrical conductivity of the designed catalysts. The low manufacturing cost, robustness, and durability make this catalyst viable in solar energy conversion and storage applications.