Bifunctional electrocatalyst based on Cu/Ce MOFs-derived mesoporous Ce doped Cu/CuO nanorods supported on the oaks-derived activated carbon particles for overall water splitting

Abstract

The development of a cheap and high-performance electrocatalyst that can drive both O₂ and H₂ evolution reactions (OER and HER) is of great importance, which remains a great challenge. In this regard, the Cu-based electrocatalysts are less reported for overall water splitting. Herein, a bifunctional electrocatalyst was fabricated based on a three-dimensional porous Ce doped Cu/CuO nanorods supported on as-prepared oaks-derived activated carbon particles. At first, the oaks-derived activated carbon particles were prepared via a facile carbonization and activation of oak fruit shells, then, the Cu/Ce MOFs precursor was grown on the as-prepared oaks-derived activated carbon (AC) particles via a facile hydrothermal method. Then, it entirely converted to the MOFs-derived Ce doped Cu/CuO supported on the surface of oaks-derived AC particles (Ce doped Cu/CuO@AC). Remarkably, due to the specific engineering of electronic structure and unique mesoporous structure, fast electron/mass transport, and effective gas releasing, the resulting Ce doped Cu/CuO@AC electrocatalysts offers superb OER performance as well as effective HER activity in the alkaline medium. Moreover, a symmetric two electrode water splitting electrolyzer based on Ce doped Cu/CuO@AC carbon felt electrodes deliver a current density of 10 mA cm⁻² at a cell voltage as low as 1.51 V. This study provides a new approach to enhance the bifunctional catalytic activity of Cu based nanostructures for overall water splitting with significant potential for low cost and highly efficient H₂ production.