N-functionalized Ti2C MXene as high-performance adsorbent for strontium ions: a first-principles study

TL;DR

This study uses first-principles calculations to show that N-functionalized Ti2C MXene effectively adsorbs strontium ions, offering a promising, thermally stable material for radionuclide removal.

Contribution

It demonstrates that N-functionalization enhances Ti2C MXene's adsorption capacity for Sr ions through strong N-Sr bonds, providing new insights for designing MXene-based adsorbents.

Findings

N-functionalized Ti2C has higher Sr adsorption capacity than other surface groups.

Strong N-Sr chemical bonds improve interaction strength.

Adsorption structure remains thermally stable at room temperature.

Abstract

Radionuclides sequestration through adsorption technology has attracted much attention due to its unique characters such as high removal efficiency, low cost, and ease of operation. In this work, the interaction mechanism of N-functionalized Ti2C MXene (Ti2CN2) as a potential adsorbent for the removal of strontium ions is investigated by using first principles method. Our results show that surface N atoms are connected to Sr ions by a robust chemical N-Sr bond, which provides a stronger interaction and greater capacity (1.291g g-1) of Sr ion adsorption on Ti2CN2 than Ti2C with other surficial groups O, F and OH. Furthermore, the thermal stability of the adsorption structure of Sr on Ti2CN2 with full layer coverage at room temperature is verified by using ab initio molecular dynamics simulations. Our results are expected to provide a new perspective for the design of MXene materials as adsorbent for radionuclide.