Ti3C2 MXene based materials for the controlled release and the detection of volatile organic compounds

• Main Author: Ciou, Jing-Hao
• Other Authors: Lee Pooi See
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/151720
• Institution: Nanyang Technological University

The emergence of MXene, a group of two-dimensional materials, has shown its potential to be used in diverse fields especially in energy storage since 2011. Being inspired by the intriguing properties of MXene used for energy storage, such as the high electrical conductivity and the ability to accommodate ions in the interlayer space with controllable manner, the possibility to accommodate the volatile organic compounds (VOCs) in the interlayer space and to release the entrapped VOCs with controllable approaches have drawn our attention for the potential application on the controlled release of odors. Additionally, due to the abundant termination groups on the surface of MXene, it could also be the promising candidate for the detection of VOCs. The surface functional groups on MXene could not only serve as the active sites for the interaction between MXene and VOC molecules but also provide the potential anchoring points for the surface functionalization, endowing diverse surface properties by the additional termination groups. In this thesis, Ti3C2 MXene is selected to be the main material for the studies of VOC controlled release and detection due to its superior electrical conductivity, versatile surface functional groups and better thermal stability among the MXene materials. With the polar functional group on the pristine Ti3C2 MXene surface, Ti3C2 MXene is first applied to perform the controlled release of polar aroma VOC. The surface of the Ti3C2 MXene is also functionalized with non-polar groups to improve the adsorption of the non-polar VOCs. With the improved adsorption of non-polar VOCs by surface functionalized Ti3C2 MXene, the modified MXene is further applied for the detection of the non-polar VOC. The controlled release of the aroma VOC is monitored by the ex-situ and in-situ X-ray diffraction, which show the significant change of the interlayer distance during the adsorption and desorption of the VOCs. The adsorption mechanism is also proved by the X-ray photoelectron microscopy. The modified Ti3C2 MXene also shows the improve sensing specificity towards the non-polar VOC. These findings offer the insight of Ti3C2 MXene as a potential material used for the controlled release of aroma VOCs and the detection of VOCs.