MXene-derived Ti3C2-Co-TiO2 nanoparticle arrays via cation exchange for highly efficient and stable electrocatalytic oxygen evolution.

A cation exchange strategy is proposed to convert layered Ti3C2-Na-TiO2 MXene nanofibers into Ti3C2-Co-TiO2 MXene nanoparticle arrays with open-layered 3D structure and numerous heterogeneous interfaces, which deliver excellent oxygen evolution reaction (OER) activity.