Co-Co3O4@carbon core–shells derived from metal−organic framework nanocrystals as efficient hydrogen evolution catalysts
Co-metal−organic frameworks (MOFs), core-shell, NaBH4 hydrolysis, pyrolysis, synergistic effect
ABSTRACT Controllable pyrolysis of metal−organic frameworks (MOFs) in confined spaces is a promising strategy for the design and development of advanced functional materials. In this study, Co-Co3O4@carbon composites were synthesized via pyrolysis of a Co-MOFs@glucose polymer (Co-MOFs@GP) followed by partial oxidation of Co nanoparticles (NPs). The pyrolysis of Co-MOFs@GP generated a core–shell structure composed of carbon shells and Co NPs. The controlled partial oxidation of Co NPs formed Co-Co3O4 heterojunctions confined in carbon shells. Compared with Co-MOFs@GP and Co@carbon-n (Co@C-n), Co-Co3O4@carbon-n (Co-Co3O4@C-n) exhibited higher catalytic activity during NaBH4 hydrolysis. Co-Co3O4@C-II provided a maximum specific H2 generation rate of 5,360 mL·min−1·gCo−1 at room temperature due to synergistic interactions between Co and Co3O4 NPs. The Co NPs also endowed Co-Co3O4@C-n with the ferromagnetism needed to complete the magnetic momentum transfer process. This assembly-pyrolysis-oxidation strategy may be an efficient method of preparing novel nanocomposites.
Tsinghua University Press
Yanyan Liu,Guosheng Han,Xiaoyu Zhang,Congcong Xing,Chenxia Du,Huaqiang Cao,Baojun Li, Co-Co3O4@carbon core–shells derived from metal−organic framework nanocrystals as efficient hydrogen evolution catalysts. NanoRes.2017, 10(9): 3035–3048