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 H-2 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 mu g cm(-2) of catalyst, while lowering the catalyst amount to 8 mu g cm(-2), unprecedented turnover frequency of 0.20 s(-1) and mass activity of approximate to 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.