MOF-derived N-doped carbon nanosticks coupled with Fe phthalocyanines for efficient oxygen reduction

Abstract

The rational design and preparation of atomic-level dispersed non-platinum catalysts to achieve efficient oxygen reduction reactions (ORR) is worth exploring for clean energy conversion and storage technology. Herein a simple self-templating strategy is demonstrated to obtain MIL-68-NH2-x series using pyridine as a surfactant to realize micron-scale to nanosized conversion. Among them, the as-prepared MIL-68-NH2-300 owns a large specific surface area and abundant pore defects after thermal treatment, which can effectively adsorb and anchor Fe phthalocyanines (FePc). In this case, MOF-derived N-doped carbon nanosticks coupled with FePc molecules (FePc@NCNS) exhibit an excellent electrocatalytic ORR activity with a positive half-wave potential (0.904 V), a large diffusion-limited current density (6.17 mA cm−2) and a high current retention after 20 h (95.7%). Furthermore, the high performance of ORR is confirmed by the relevant theoretical calculations on O2 adsorption ability. These above results will pave the way for MOF-derived carbon nanomaterials with specific morphological dimensions for high-performance energy conversion and storage.