Amorphous C,N Codoping Cobalt Phosphates Simply Fabricated via a Mild Host-Guest Strategy as Bifunctional Electrocatalysts for Zinc-Air Batteries

It is crucial to develop efficient bifunctional electrocatalysts toward oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) for practical application. Herein, for the first time, Co-based phosphate ((H(2)en)(0.5)CoPO4)) as a precursor with unique CoO4 tetrahedra and diprotonated ethanediamine template (H(2)en) is simply and rapidly prepared, and the amorphous cobalt phosphate can be obtained via a mild calcination of this host-guest material. Furthermore, the optimal calcined electrocatalyst exhibits a low overpotential of 284 mV at 10 mA cm(-2) toward OER and 0.78 V of half-wave potential for ORR in 1.0 m KOH electrolyte. Furthermore, this bifunctional electrocatalyst as the cathode of zinc-air batteries displays a high-power density of 178 mW cm(-2) and specific capacitance of 754.5 mAh g(-1), accompanied by good cycling stability (for 50 h of operation). This work offers a new strategy to design heteroatom doping electrocatalysts using this host-guest method under a mild and environmental condition.

Automated summary

This work presents a new strategy to design bifunctional electrocatalysts with heteroatom doping, showing great performance in the oxygen evolution reaction and oxygen reduction reaction. As the cathode of zinc-air batteries, this electrocatalyst exhibits high-power density, specific capacitance, and good cycling stability.