Bacterial cellulose aerogel modified with carbon quantum dots for formaldehyde perception removal

Formaldehyde (FA), a highly toxic, colorless and low concentration odorless indoor pollutant, has a substantial threat to human health. Development of smart material that can simultaneously remove FA and make the users percept the removal process through vision and/or smell, or the perceptual purification technology, is in high demand. Herein, the bacterial cellulose aerogel (BC) modified with carbon quantum dots (CQD) is designed for perceptual removal of indoor FA. Benefiting from the abundant surface functional groups on CQD and their effect on the pore structure optimization in BC aerogel, the FA adsorption capacity of CQD/BC aerogel is 0.08 mg/g, while that of pristine BC aerogel is 0.05 mg/g. Meanwhile, originating from the Schiff base reaction between amino groups on CQD and FA, CQD/BC aerogel exhibits obvious fluorescence quenching upon exposure to FA. The quenching is attributed to the synergistic effect of static quenching (formation of non-fluorescent ground compounds) and dynamic quenching (intermolecular charge transfer between excited state molecules). This CQD/BC aerogel successfully achieves the dual-functional integration of fluorescence sensing and adsorption through rational material design, enabling real-time perceiving of FA adsorption removal process on a monolithic platform.