Fluorescent carbon dots crosslinked Salix psammophila microcrystalline cellulose interpenetrating hydrogel system for sensitive detection and efficient adsorption of Fe3+

To combat the contaminating effects of heavy-metal ions on water resources, we prepared blue photonitrogen-doped carbon quantum dots (NCDs) from Salix psammophila (SP) as a raw material, doped them into a microcrystalline cellulose hydrogel, and successfully created a composite hydrogel (NCDs-SP-MCC-gels) for concurrent fluorescence detection and Fe3+ adsorption. The NCDs-SP-MCC-gels was examined for their shape, chemical composition, fluorescence characteristics, and adsorption behaviors. Results demonstrated that the NCDs-SP-MCC-gels displayed a broad linear range of Fe3+ fluorescence response (200–1000 mg/L; detection limit = 3.90583 mg/L) and a high adsorption capacity for Fe3+ (610 mg/g). The adsorption data fitted the Langmuir and pseudo-second-order models well. Further research was conducted on Fe3+ detection and adsorption onto the NCDs-SP-MCC-gels. This study proposes a green and sustainable way to create a material for the detection and absorption of heavy-metal ions.