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 Ti3C2Tx (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., similar to 300 mg g(-1) for Cr(VI)). Crucially, leveraging the photothermal conversion of Ti3C2Tx 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.