High quality and high performance adsorption of Congo red using as-grown MWCNTs synthesized over a Co-MOF as a catalyst precursor via the CVD method

Abstract

A Co(II) metal–organic framework (MOF) based on the pyridyl-amide-carboxylate-3-(2-pyridinecarboxylic acid)amido pyridine (HPCAP) ligand, namely [Co(PCAP)₂]·2H₂O (1), has been hydrothermally synthesized and structurally characterized, which was firstly used as a combined catalyst precursor to synthesize multi-walled carbon nanotubes (MWCNTs). The decomposition of ethylene in the presence of the Co-MOF by the chemical vapor deposition (CVD) method at 800 °C led to successful production of high quality as-grown MWCNT products. Interestingly, the as-grown MWCNTs exhibit high performance in the selective adsorption of Congo red (CR) with an adsorption capacity of 1639 mg g⁻¹.