Hierarchical porous carbons (HPCs) are highly efficient supports for various
remarkable catalytic systems. However, templates are commonly utilized
for the preparation of HPCs, and the postremoval of the templates is uneconomical,
time-consuming, and harmful for the environment in most cases.
Herein, a new humidity-induced nontemplating strategy is developed to
prepare 1D HPC with rich topologies and interconnected cavities for catalysis
and energy storage applications. Porous electrospun nanofibers as calcination
precursors are prepared via a humidity-induced phase separation strategy. A
nitrogen-doped hierarchical porous carbon nanofiber (HPCNF), loading Co/
Co3O4 hetero-nanoparticles as exemplary nonprecious-metal active substance
(Co/Co3O4@HPCNF), is fabricated through the subsequent hydrothermal
and pyrolysis treatment. The internal mesopore and cavity structure can be
simply controlled by varying environment humidity during the electrospinning
process. Benefiting from the unique topology, Co/Co3O4@HPCNF
exhibits superior bifunctional activity when being used as electrocatalysts
for oxygen reduction/evolution reactions. Moreover, the hybrid catalyst also
demonstrates a remarkable power density of 102.5 mW cm−2, a high capacity
of 748.5 mAh gZn
−1, and long cycle life in Zinc–air batteries. The developed
approach offers a facile template-free route for the preparation of HPCNF
hybrid and can be extended to other members of the large polymer family for
catalyst design and energy storage applications.
Researcher/Author: Lidong Tian, Dongxiao Ji, Shan Zhang, Xiaowei He, Seeram Ramakrishna and Qiuyu Zhang
Small 2020, 16, 2001743; https://doi.org/10.1002/smll.202001743