In situ growth of ultrathin covalent triazine frameworks on unmodified cellulose II beads for enhanced dye pollutant removal

cellulose II beads@covalent triazine frameworks (CBCs) are prepared by in situ growth of ultra-dispersed covalent triazine frameworks (CTF) using unmodified regenerated cellulose beads (CBs) as templates. The CBCs as a whole are three-dimensional structures consisting of a layered pore structure and a continuous ultrathin CTF, which combines a functional surface with highly efficient mass transfer. The thickness of the CTF in the prepared CBCs can be controlled at 32–83 nm, which enables the CBC to have a dye adsorption efficiency of up to 191 mg g −1 and an ultrafast dye removal time (Methylene Blue, 0.5 min, 95 %). Molecular dynamics simulations revealed the mechanism for CTF growth on the surface of unmodified cellulose II rather than on the surface of cellulose Ⅰ, and the effects of the hydrophilic/hydrophobic surfaces of cellulose I and cellulose II on the growth of CTF were determined. This is the first use of unmodified cellulose II as a template for the in situ growth of ultrathin CTF and provides important insights into dynamic CTF-cellulose interactions. This research provides a new cost-effective strategy for preparation of ultra-dispersed CTF based on large-scale cellulose templates.