Enhancement of oxygen evolution reaction by in situ growth PMo12@ZIF-67 on MWCNTs via perylene bisimide-based dispersant

Abstract

The combination of metal organic frameworks (MOFs) and multi-walled carbon nanotubes (MWCNTs) can significantly improve their electrochemical performance. However, in most cases, chemical pre-treatment of MWCNTs is inevitable, which may compromise the ideal performance of the final composites. Herein, via a noncovalent functionalization method, PMo12@ZIF-67 was in situ grown on the surfaces of MWCNTs with the assistance of a new dispersant containing two triethylenetetramine (TETA) segments. In order to enhance the coordination of Co metal ions with the surface of MWCNTs, phenolic hydroxyl groups were incorporated into the dispersant through reaction with gallic acid (GA). After annealing, homogeneous CNT/Co6Mo6C2/Co composites were obtained, and they showed excellent performance on oxygen evolution reaction (OER). At a current density of 10 mA cm−2, the lowest overpotential is 263 mV, of which the performance is superior to that achieved by other in situ growth methods. The uniform distribution of coordination sites and subsequent in situ growth of MOFs on MWCNTs improved the electrical conductivity of the derivatives, thereby enhanced the utilization of catalytic active sites. This study presents a novel approach for synthesizing carbon-doped electrocatalytic materials, which demonstrates significant potential in various electrochemical applications.