Enabling highly efficient electrocatalytic oxygen reduction and evolution reaction by established strong MnO/Co-support interaction

Abstract

Exploring a facile and cost-efficient approach to synthesize electrocatalysts that promoting the interconversion between H2O and O2 remains a crucial challenge. In this work, we report a convenient and effective strategy to synthesis Co metal and MnO immobilized on carbon nanotubes (MnO/Co-CNTs) vis strong metal-support interaction (SMSI). The CNTs support anchored abundant MnO/Co nanoparticles (NPs) in a small size of ~2 nm, when the strong interaction between them suppressed the homogeneous nucleation of MnO/Co during high temperature sintering. Thus, enormous well-dispersed catalytic active sites are produced on the conductive CNTs. Together with the boosted charge transfer between MnO/Co and support, the catalytic activity of MnO/Co-CNTs is eventually significantly promoted. The catalyst shows an efficient oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. Furthermore, SMSI alleviate the agglomeration of NPs and secure the active sites during electrochemical reactions, which account for the enhanced catalytic durability for ORR, OER and HER. In consequence, the MnO/Co-CNTs catalyst shows excellent performance for rechargeable Zn-air battery, and can be utilized to catalyze overall water splitting to produce hydrogen and oxygen. This work manifests a promising approach for optimizing the catalytic performance of the NPs.