Efficient Oxygen Evolution Reaction Catalyzed by Ni/NiO Nanoparticles Produced by Pulsed Laser Ablation in Liquid Environment.

Electrochemical water‐splitting, sustained by renewable energy, is aimed at green H2 production. Efficient and sustainable electrocatalysts are required for a proper energy transition. Oxygen evolution reaction (OER) in alkaline electrolyte can be pursued by using earth‐abundant elements‐based catalysts, such as Ni oxyhydroxides. A proper optimization of intrinsic properties and synthesis procedure is still needed. Herein, the synthesis of Ni/NiO nanoparticles (NPs) through a physical and green technique, pulsed laser ablation in liquid (PLAL), is presented. Ablating a Ni target in deionized water, at different ablation times, leads to NP dispersions used for realization of OER electrode onto graphene paper. Ion‐beam analysis of catalysts amount and homogeneity of NP‐based electrode is performed for the electrode optimization in terms of electrochemical performances. An overpotential at 10 mA cm−2 of 306 mV is achieved for 40 μg cm−2 of catalyst, while lowering the catalyst amount to 8 μg cm−2, unprecedented turnover frequency of 0.20 s−1 and mass activity of ≈1.3 A mg−1 are reached. These data show that Ni/NiO NPs produced by PLAL are highly effective for OER in alkaline media and encourage the use of PLAL as a green and efficient technique for electrocatalyst production. [ABSTRACT FROM AUTHOR]