Halogenated Ti<sub>3</sub>C<sub>2</sub> MXenes Prepared by Microwave Molten Salt for Hg<sup>0</sup> Photo‐Oxidation
Cheng Xie, Lei Xu, Jinhui Peng, Libo Zhang, Xueqian Wang, Jianying Deng, Mickaël Capron, Vitaly V. Ordomsky
Abstract
Abstract Ti 3 C 2 MXenes with different halogen modifications are prepared rapidly and efficiently by microwave molten salt method, and the MXene surface functional group modification is successfully achieved to address the problems of low purity, complex functional groups, and uncontrollable energy band structure of MXenes obtained by traditional liquid phase etching. Among them, the modification of the iodine (I) functional group onto the surface of Ti 3 C 2 changes the energy band structure and band gap, resulting in easier photoexcitation and more photogenerated carriers. The increased Fermi energy is closer to the conduction band, the decreased surface work function weakens the electron confinement ability. The photogenerated carriers can migrate to the surface of the material more easily with extended lifetime, so the activity of the catalyst is improved. Further, for gaseous monomeric mercury (Hg 0 ) photo‐oxidative removal, Ti 3 C 2 ‐I 2 exhibits 85.5% efficiency of Hg 0 photo‐oxidative removal under visible light. Based on the experimental characterization and density functional theory calculations, a mechanism for the photo‐oxidative removal of Hg° from Ti 3 C 2 ‐I 2 MXene is proposed, which provides a valuable strategy for studying Ti 3 C 2 MXenes in the field of photocatalysis.