Ru doping induced interface engineering in flower-liked CoMoO4-RuO2 boosts oxygen electrocatalysis for rechargeable Zn-air battery.

A novel CoMoO 4 -RuO 2 heterogeneous catalyst with flower-liked morphology was developed as a highly efficient bifunctional oxygen electrocatalyst for Zn-air battery. [Display omitted] Constructing heterogeneous catalysts can significantly boost the electrocatalytic activity due to the improved intrinsic catalytic activity induced by tailored electronic structure and optimized chemisorption to the reaction intermediates. RuO 2 based electrocatalysts are especially attractive due to the high catalytic activity of RuO 2. To reduce the usage of noble metal and improve the catalytic activity of catalyst, CoMoO 4 -RuO 2 micro-flower was synthesized using a facile hydrothermal-calcination method in this work. CoMoO 4 -RuO 2 exhibits a low overpotential of 177 mV at 10 mA cm−2 for oxygen evolution reaction (OER) and a high half-wave potential of 0.858 V for oxygen reduction reaction (ORR). Moreover, the Zn-air battery assembled using CoMoO 4 -RuO 2 exhibit shows a high maximum discharge power density of 149 mW cm−2 and a large open circuit voltage of 1.38 V. The good performance can be attributed to the incorporation of RuO 2 , which not only induces extra catalytic active sites, but also forms heterojunction with CoMoO 4 to optimize the electronic structure of CoMoO 4 -RuO 2 , thereby achieving a better equilibrium of absorption and desorption of intermediates. The work provides insights into designing RuO 2 based electrocatalysts for advanced electrocatalysis. [ABSTRACT FROM AUTHOR]