Effective adsorption and sensitive detection of Cr6+ by degradable collagen-based porous fluorescent aerogel

Although the treatment of heavy metal ions in environmental wastewater has attracted researchers' attention, it is still a great challenge to prepare green adsorbents with biodegradability, high adsorption efficiency, and high detection sensitivity. Herein, a bio-based, 3D network structured, luminescent aerogel with excellent adsorption efficiency and detection sensitivity for detecting and removing Cr6+ in an aqueous solution was demonstrated. The bifunctional aerogels were designed and synthesized using waste collagen, polyethyleneimine (PEI), and carbon dots cross-linked by aldehyde cellulose nanofibers. Sorption experiments were designed to investigate the sorption properties of Cr6+ through response surface methodology (RSM). The kinetic model (pseudo-second-order model) and isotherm model (Langmuir model) well-matched with the adsorption process. The maximum adsorption capacity by degradable collagen-based porous fluorescent aerogel for Cr6+ reached 103.3 mg.g−1. In addition, there was a good linear relationship between the fluorescence intensity of the fluorescent aerogel and the Cr6+ concentration. In addition, the adsorption mechanism, fluorescence properties, microstructure, and surface morphology have been thoroughly studied. The proposed bifunctional aerogels could be attractive for smart sorbents in the field of removal and detection of metal ions in wastewater.