Conductive bimetal organic framework nanorods decorated with highly dispersed Co <sub>3</sub> O <sub>4</sub> nanoparticles as bi-functional electrocatalyst
Yaxin Duan, Haitao Liu, Huabing Zhang, Shaojie Ke, Shuaize Wang, Meiling Dou, Feng Wang
Abstract
Abstract The poor electronic conductivity and low intrinsic electrocatalytic activity of metal organic frameworks (MOFs) greatly limit their direct application in electrocatalytic reactions. Herein, we report a conductive two-dimensional π – d conjugated Ni and Co bimetal organic framework (MOF)—NiCo-(2,3,6,7,10,11-hexaiminotriphenylene) (NiCo-HITP) nanorods decorated with highly dispersed Co 3 O 4 nanoparticles (NPs) as a promising bi-functional electrocatalyst towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) through an effective and facile strategy by modifying the rod-shaped -Ni 3 HITP 2 crystals using cobalt ions. The triggered electrocatalytic activity of the resulting MOF-based materials was achieved by increasing the electrical conductivity (7.23 S cm −1 ) originated from Ni 3 HITP 2 substrate and also by creating the cooperative catalysis sites of Co–N x and Co 3 O 4 NPs. Optimized syntheses show a promising ORR activity with a high half-wave potential (0.77 V) and also a significantly improved OER activity compared with pure Ni 3 HITP 2 in alkaline electrolyte. Furthermore, a rechargeable Zn–air battery using the as-prepared material as air-cathode also shows a high power density (143.1 mW cm −2 )—even comparable to a commercial Pt/C-RuO 2 -based battery. This methodology offers a new prospect in the design and synthesis of non-carbonized MOF bi-functional electrocatalysts for efficient catalysis towards ORR and OER.