Adsorption of Copper Ions on the Surface of Multilayer Ti3C2Tx MXenes with Mixed Functionalization

Nowadays a new class of two-dimensional materials, MXenes, is attracting considerable attention as nanoadsorbents for the removal of heavy-metal ions from water. Pollutants such as copper and other heavy metals possess a negative impact on human health and the quality of natural ecosystems when their concentration exceeds an acceptable limit, which makes it urgent to develop cheap and effective methods to reduce the concentration of such pollutants. In this work we study the adsorptive properties of Ti3C2Tx MXenes with mixed functionalization by –O, –F, and –OH surface groups in relation to copper Cu(II) ions. Herein, multilayer MXene particles are investigated, since their yield is much greater than that of single-layer particles when using standard synthesis methods, and the experimental results are compared with previously published data for single-layer MXenes. It is established that, at low concentrations (below 50 mg/L), multilayer Ti3C2Tx MXenes demonstrate a comparable adsorption capacity of ~102 mg/g which makes it possible to use them for practical applications.