Halogenated Ti3C2 MXenes Prepared by Microwave Molten Salt for Hg0 Photo-Oxidation |
| |
Authors: | Cheng Xie Lei Xu Jinhui Peng Libo Zhang Xueqian Wang Jianying Deng Mickael Capron Vitaly Ordomsky |
| |
Affiliation: | 1. Faculty of Metallurgical and Energy Engineering, National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, The Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, 650093 P. R. China;2. Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650093 P. R. China;3. Unité de Catalyse et Chimie du Solide, UMR CNRS 8181, Université de Lille, F-59000 Lille, France |
| |
Abstract: | Ti3C2 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 Ti3C2 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 (Hg0) photo-oxidative removal, Ti3C2-I2 exhibits 85.5% efficiency of Hg0 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 Ti3C2-I2 MXene is proposed, which provides a valuable strategy for studying Ti3C2 MXenes in the field of photocatalysis. |
| |
Keywords: | DFT calculations halogens Hg0 removal microwave molten salts MXenes photo-oxidations |
|
|