Fabrication of CNT/cobalt hexacyanoferrate core/shell nanostructured for boosting the removal of crystal violet from water

Carbon nanotubes (CNTs) are highly promising materials for the adsorption of dyes from water. Recently, there has been a growing interest in Prussian blue-type coordination polymers due to their inexpensive nature, chemical stability, and simple synthesis using non-toxic metals that are prevalent in the earth. The results present a straightforward technique for effectively altering the surface of CNT using cobalt-iron-based prussian blue (CoFe-PB). The procedure led to a significant increase in the removal of crystal violet (CV) from water relative to the bare CNTs. The maximum removal efficiency (about 93 %) of CV dye was obtained at pH 6 with fast saturation time (15 min). The use of the coating approach yields a core–shell structure consisting of CNT as the core and a CoFe-PB shell. The CoFe-PB shell, with a thickness of 10–15 nm, forms a highly conformal coating that completely covers the CNT. The high conformance of the coating is considered an essential characteristic for its strong adsorption performance. The method demonstrates the significant potential of prussian blue-type materials, when appropriately coated, as very effective adsorbent materials.