Fluorescent cellulose micron fibers based hydrogel incorporating amino-modified carbon dots for effective adsorption and detection of hazardous Cr(VI)

To remove hazardous Cr (VI) from wastewater, a novel 3D porous fluorescent cellulose-based hydrogel was synthesized to remove Cr (VI) from wastewater. It was created by loading carbon dots into cellulose micron fibers gel matrix via physical action and hydrogen bonds. The hydrogel’s morphology, crystalline structure, chemical composition, optical properties, sorption, and detection properties were analyzed. It exhibited good fluorescence properties with an absolute quantum yield of 15.94%. The hydrogel had a maximum adsorption capacity of 155.8 mg/g, with adsorption isotherms fitting the Langmuir model and kinetics fitting the pseudo-second-order model. It also showed selective and sensitive detection of Cr(VI) with a detection limit of 5 mg/L and an analytical linear range of 10–200 mg/L. FTIR and XPS analyses revealed that cellulose micron fibers improved adsorption ability, and carbon dots served as fluorescent probes for Cr(VI) detection. The material’s excellent mechanical properties, including a 180° anti-bending angle, 47.96% compression ratio, and 360° torsion angle, make it a candidate product that is both efficient for detection and capable of removing Cr(VI) from wastewater.