| Autor: |
Emerenciano AA; Materials Science and Engineering Postgraduate Program, UFRN, Natal 59078-570, Brazil., do Nascimento RM; Materials Science and Engineering Postgraduate Program, UFRN, Natal 59078-570, Brazil., Barbosa APC; Materials Science and Engineering Postgraduate Program, UFRN, Natal 59078-570, Brazil., Ran K; Central Facility for Electron Microscopy GFE, RWTH Aachen University, 52074 Aachen, Germany.; Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany., Meulenberg WA; Forschungzentrum Jülich GmbH, Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1), 52428 Jülich, Germany.; Jülich Aachen Research Alliance: JARA-Energy, D-52425 Jülich, Germany.; Inorganic Membranes, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands., Gonzalez-Julian J; Forschungzentrum Jülich GmbH, Institute of Energy and Climate Research, Materials Synthesis and Processing (IEK-1), 52428 Jülich, Germany.; Department of Ceramics, Institute of Mineral Engineering, RWTH Aachen University, D-52074 Aachen, Germany. |
| Abstrakt: |
Two-dimensional (2D) MXene materials have recently been the focus of membrane research due to their unique properties, such as their single-atomic-layer thickness, flexibility, molecular filtration abilities and microstructural similarities with graphene, which is currently the most efficient precursor material for gas separation applications. In addition, the potential to process nanoscale channels has motivated investigations of parameters which can improve membrane permeability and selectivity. Interlayer spacing and defects, which are still challenging to control, are among the most crucial parameters for membrane performance. Herein, the effect of heat treatment on the d-spacing of MXene nanosheets and the surface functionalization of nanolayers was shown regarding its impact on the gas diffusion mechanism. The distance of the layers was reduced by a factor of over 10 from 0.345 nm to 0.024 nm, the defects were reduced, and the surface functionalization was maintained upon treatment of the Ti 3 C 2 membrane at 500 °C under an Ar/H 2 atmosphere as compared to 80 °C under vacuum. This led to a change from Knudsen diffusion to molecular sieving, as demonstrated by single-gas permeation tests at room temperature. Overall, this work shows a simple and promising way to improve H 2 /CO 2 selectivity via temperature treatment under a controlled atmosphere. |
