Multifunctional chitosan non-woven fabrics modified with terylene carbon dots for selective detection and efficient adsorption of Cr(VI)

A novel terylene carbon dots (TCDs) were successfully synthesized by a one-step solvothermal method, and further modified onto chitosan non-woven fabrics (CNF) for selective detection and effective removal of Cr(VI). Compared with TCDs, chitosan non-woven fabrics modified by carbon dots (CNF-TCDs3) exhibited higher selectivity and lower detection limit for Cr(VI) (The limit of detection (LOD) is 0.15 mg/L). In addition, CNF-TCDs3 showed a rapid and effective removal of Cr(VI), and still maintain a high relative removal rate (above 92%) after five times recirculation. The adsorption equilibrium could be reached in only 8 min, and the maximum adsorption capacity was 203 mg/g. The adsorption process conformed to the Langmuir model, and the fitting correlation is R2 = 0.99. The fluorescence response and efficient adsorption mechanisms of the CNF-TCDs3 toward Cr(VI) were mainly attributed to the internal filtering effect and the amino and hydroxyl groups in chitosan. Significantly, this functionalized fabrics CNF-TCDs3 were successfully applied to semi-quantitatively detect on a smartphone-integrated-device and efficiently remove Cr(VI) in real samples.