Ni-Rh-based bimetallic conductive MOF as a high-performance electrocatalyst for the oxygen evolution reaction.

Abstract

Metal-organic frameworks (MOFs) have recently been considered the promising catalysts due to their merits of abundant metal sites, versatile coordination groups, and tunable porous structure. However, low electronic conductivity of most MOFs obstructs their direct application in electrocatalysis. In this work, we fabricate an Ni-Rh bimetallic conductive MOF ([Ni2.85Rh0.15(HHTP)2]n/CC) grown in situ on carbon cloth. Abundant nanopores in the conductive MOFs expose additional catalytic active sites, and the advantageous 2D π-conjugated structure helps accelerate charge transfer. Owing to the introduction of Rh, [Ni2.85Rh0.15(HHTP)2]n/CC exhibited substantially improved oxygen evolution reaction (OER) activity and exhibited only an overpotential of 320mV to achieve the current density of 20mAcm-2. The remarkable OER performance confirmed by the electrochemical tests could be ascribed to the synergistic effect caused by the doped Rh together with Ni in [Ni2.85Rh0.15(HHTP)2]n/CC, thereby exhibiting outstanding electrocatalytic performance.