3D magnetic MXene as promising adsorbent materials for Ag(I) removal.

An efficient route is proposed to synthesize a novel three-dimensional (3D) magnetic MXene aerogel (3D MXene/Fe 3 O 4). 3D MXene were synthesized by self-assembly of 2D MXene Ti 3 C 2 T x using ethylenediamine (EDA) as crosslinking inducer, then Fe 3 O 4 was in situ coprecipitation onto 3D MXene. 3D MXene/Fe 3 O 4 was applied as an adsorbent for Ag(I) removal from aqueous solutions. 3D MXene/Fe 3 O 4 exhibits a cross-linked 3D porous network with magnetic Fe 3 O 4 nanoparticles uniformly dispersed on its surface and edges. The maximum adsorption capacity of 3D MXene/Fe 3 O 4 for Ag(I) was 2385 mg g−1. The kinetics and isothermal process during adsorption were described accurately by the pseudo-second-order model and the Freundlich isotherm model, and the adsorption process was driven by chemisorption and multilayer adsorption, where the diffusion mechanism involved surface diffusion and intraparticle diffusion. Furthermore, the 3D MXene/Fe 3 O 4 are recyclable, retaining 71% of the initial removal rate after 5 adsorption/desorption cycles. [Display omitted] • 3D MXene aerogel was formed by EDA induced self-assembly of nanosheets and subsequently Fe 3 O 4 was assembled. • 3D MXene/Fe 3 O 4 exhibits a cross-linked porous network and Fe 3 O 4 uniformly were dispersed on its surface and edges. • 3D MXene/Fe 3 O 4 provides a controllable channel for the transmission of Ag(I), and can quickly be recycled after adsorption. • The adsorption capacity of 3D MXene/Fe 3 O 4 for Ag(I) is 2385 mg.•g−1. [ABSTRACT FROM AUTHOR]