Photo-induced self-healing gel adsorbent for sustainable and efficient removal of Cr(VI) from water

Smart adsorbents with responsive self-healing ability will be promising, as they can meet the desirable requirements of sustainable and efficient usage in water treatment. Herein, a photo-induced self-healing gel adsorbent is fabricated by the combination of transition metal carbides Ti 3 C 2 T x (MXene), polyethyleneimine (PEI), and poly(N,N-dimethylacrylamide) (PDMAA) for sustainable and efficient removal of specific target Cr(VI) from water. PEI, as a potent adsorptive motif, endows the gel with high maximum adsorption capacity ( q m ) (i.e., ∼300 mg g −1 for Cr(VI)). Crucially, leveraging the photothermal conversion of Ti 3 C 2 T x and the self-healing repair of PDMAA, the gel is imbued with rapid photo-induced self-healing ability, which facilitates its sustainability in adsorption application. The photoinduction applied to the damaged gel adsorbent enables its rapid self-healing repair, as well as maintains its efficient removal efficiency for reapplication, which makes it more suitable for long-time usage in environments. This work provides a new insight into the application of smart adsorbents for sustainable and efficient adsorption in the field of wastewater treatment.