Hollow nanotube arrays of CoP@CoMoO4 as advanced electrocatalyst for overall water splitting

Abstract

Developing cost-effective and high-performance bifunctional electrocatalysts for water-splitting in alkaline electrolytes is considered to be one of the prerequisites for exploring hydrogen energy technology. Herein, we present a kind of ZnO template etching strategy coupled with electrodeposition process to prepare MOF-derived CoP@CoMoO4 hollow nanotubes (CoP@CoMoO4 HNTs). The CoP@CoMoO4 HNTs exhibit outstanding electrocatalytic performances, which only require a low potential of 34 and 120 mV to deliver 10 mA cm−2 current density for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Furthermore, the assembled electrolysis system, integrated with the as-prepared CoP@CoMoO4 HNTs, just needs a quite low voltage of 1.51 V to drive 10 mA cm−2 current density and also exhibits excellent durability in alkaline electrolyte for over 24 h. These fascinating electrochemical properties are the results of the unique 3D hollow nanostructure, various heterogeneous interfaces between CoP and CoMoO4 as well as strong electronic configurations of the CoP@CoMoO4 HNTs catalyst. This work emphasizes the key roles of synergism in promoting electrocatalytic reaction kinetics and provides a new pathway for preparing non-noble-based electrocatalysts with astonishing properties.