Anion–Cation Double Doped Co₃O₄ Microtube Architecture to Promote High-Valence Co Species Formation for Enhanced Oxygen Evolution Reaction
2019
Li, Ruchun | Guo, Yige | Chen, Haixin | Wang, Kun | Tan, Rentao | Long, Bei | Tong, Yexiang | Tsiakaras, Panagiotis | Song, Shuqin | Wang, Yi
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.
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