(2021) Journal of Colloid and Interface Science_Metal-complexed covalent organic frameworks derived N-doped carbon nanobubble–embedded cobalt nanoparticle as a magnetic and efficient catalyst for oxone activation

Nguyen H.T., Lee J., Kwon E., Lisak G., Thanh B.X., Oh W.D., Lin K.-Y.A.

(Academic Press Inc.) Journal of Colloid and Interface Science ISSN: 219797 Vol.591 Issue. Article No. DOI: 10.1016/j.jcis.2021.01.108

While Cobalt nanoparticles (Co NPs) are useful for catalytic Oxone activation, it is more advantageous to embed/immobilize Co NPs on nitrogen-doped carbon substrates to provide synergy for enhancing catalytic performance. Herein, this study proposes to fabricate such a composite by utilizing covalent organic frameworks (COF) as a precursor. Through complexation of COF with Co, a stable product of Co-complexed COF (Co-COF) can be synthesized. This Co-COF is further converted through pyrolysis to N-doped carbon in which cobaltic NPs are embedded. Owing to its well-defined structures of Co-COF, the pyrolysis process transforms COF into N-doped carbon with a bubble-like morphology. Such Co NP-embedded N-doped carbon nanobubbles (CoCNB) with pores, magnetism and Co, shall be a promising catalyst. Thus, CoCNB shows a much stronger catalytic activity than commercial Co₃O₄ NPs to activate Oxone to degrade toxic Amaranth dye (AMD). CoCNB-activated Oxone also achieves a significantly lower Ea value of AMD degradation (i.e., 27.9 kJ/mol) than reported Ea values in previous literatures. Besides, CoCNB is still effective for complete elimination of AMD in the presence of high-concentration NaCl and surfactants, and CoCNB is also reusable over five consecutive cycles. © 2021 Elsevier Inc.

This work is supported by the Ministry of Science and Technology (MOST) (110-2636-E-005-003-), Taiwan, and financially supported by the “Innovation and Development Center of Sustainable Agriculture” from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE), Taiwan.