Laser synthesis of oxygen vacancy-modified CoOOH for highly efficient oxygen evolution.

Introducing oxygen vacancies into transition-metal oxide materials would improve their catalytic activity but usually needs high-temperature or high-pressure conditions, and multi-step procedures, and thus are time consuming and not energy efficient. Herein, laser ablation in liquids (LAL), a green, mild and effective approach, has been, for the first time, employed to prepare CoOOH nanosheets with abundant oxygen vacancies and relatively thin thickness. Our theoretical and experimental results demonstrate that oxygen vacancies can optimize the absorption of oxygen evolution reaction (OER) intermediates and improve electrical conductivity; meanwhile, the relatively thin thickness can provide more active sites, thus leading to excellent OER activity of oxygen vacancy-modified CoOOH nanosheets. This work may provide guidance for exploring other efficient non-noble metal catalysts for water oxidation.