Preparation of polyacrylamide/MXene hydrogels as highly-efficient electro-adsorbents for methylene blue removal

The composite hydrogels of polyacrylamide (PAM) with Ti3C2Tx-MXene (PAM/MXene) were prepared via a sol-gel method. The incorporation of MXene at a minimal level of 0.3 wt% in PAM/MXene hydrogel created a significant compact three-dimensional porous structure. The negatively charged PAM/MXene hydrogel exhibited high electric field sensitivity and excellent cyclic compression-resilience performance. The PAM/MXene hydrogel showed not only increased equilibrium electrosorption capacity with a 282.29 mg/g methylene blue (MB) removal compared to a traditional batch adsorption method (102.16 mg/g), but also good cyclic electrosorption-desorption properties. The electrosorption of MB was in accordance with a prefer pseudo-first-order kinetic and a Freundlich isotherm.