Co-Co3O4@carbon core–shells derived from metal−organic framework nanocrystals as efficient hydrogen evolution catalysts
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.
KeywordsCo-metal−organic frameworks (MOFs) core–shell NaBH4 hydrolysis pyrolysis synergistic effect
Unable to display preview. Download preview PDF.
- Wu, R. B.; Wang, D. P.; Rui, X. H.; Liu, B.; Zhou, K.; Law, A. W. K.; Yan, Q. Y.; Wei, J.; Chen, Z. In-situ formation of hollow hybrids composed of cobalt sulfides embedded within porous carbon polyhedra/carbon nanotubes for highperformance lithium-ion batteries. Adv. Mater. 2015, 27, 3038–3044.CrossRefGoogle Scholar
- Xing, C. C.; Liu, Y. Y.; Su, Y. H.; Chen, Y. H.; Hao, S.; Wu, X. L.; Wang, X. Y.; Cao, H. Q.; Li, B. J. Structural evolution of Co-based metal organic frameworks in pyrolysis for synthesis of core–shells on nanosheets: Co@CoOx@carbonrGO composites for enhanced hydrogen generation activity. ACS Appl. Mater. Interfaces 2016, 8, 15430–15438.CrossRefGoogle Scholar
- Liu, Y. W.; Xiao, C.; Lyu, M. J.; Lin, Y.; Cai, W. Z.; Huang, P. C.; Tong, W.; Zou, Y. M.; Xie, Y. Ultrathin Co3S4 nanosheets that synergistically engineer spin states and exposed polyhedra that promote water oxidation under neutral conditions. Angew. Chem., Int. Ed. 2015, 54, 11231–11235.CrossRefGoogle Scholar
- Shi, Q.; Wang, Y. D.; Wang, Z. M.; Lei, Y. P.; Wang, B.; Wu, N.; Han, C.; Xie, S.; Gou, Y. Z. Three-dimensional (3D) interconnected networks fabricated via in-situ growth of N-doped graphene/carbon nanotubes on Co-containing carbon nanofibers for enhanced oxygen reduction. Nano Res. 2016, 9, 317–328.CrossRefGoogle Scholar