Anion-Cation Double Doped Co3O4 Microtube Architecture to Promote High-Valence Co Species Formation for Enhanced Oxygen Evolution Reaction

Abstract

A method for efficiently catalyzing the oxygen evolution reaction (OER) represents a top priority for water electrolysis due to its multistep electron transfer pathway and sluggish kinetics. The OER activity can be promoted by generating high valence transition-metal species in the electrocatalysts. In the present work, a versatile anion-cation double doped Co3O4 (Se/Ni-Co3O4) microtube architecture is innovatively fabricated as an OER electrocatalyst, by combining reliable and template-free solvothermal strategy and calcination treatment. The obtained Se/Ni-Co3O4 possesses some desirable properties for OER including an attractive mesoporous structure, abundant exposed active species associated with surface oxygen vacancies, and fast charge transfer rate. By precisely exploring the redox reaction behavior, it is found that the effective Se and Ni double doping could readily promote the generation of active Co(IV) species. Consequently, the obtained Se/Ni-Co3O4 electrocatalyst affords a very good OER electrocatalytic activity with an onset potential of 1.47 V, small Tafel slope (62.9 mV dec-1), and excellent durability in alkaline solution, which is even superior to that obtained in the benchmark RuO2. The novel strategy introduced in this research may open a new opportunity for the rational design of highly efficient Co3O4-based OER electrocatalysts. © 2019 American Chemical Society.