Faithin Omaha eBook Collection

Download or read book Surface Functionalization of 2D Nanomaterials written by Alicia Marie Tripp and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the fundamental surface chemistry and reactivity of technologically relevant 2D nanomaterials is essential for the improvement of current nanomaterials and the design of novel materials in the future. Black phosphorus (BP) and MXenes are 2D materials that are growing in popularity due to their unique physical and chemical properties. They have great technological promise, and in order for them to reach their full potential in various applications such as sensing, contamination remediation, and energy storage, their interactions with surrounding matrices and molecular species must be controlled. Because the surface of these materials is the first to interact with their surroundings, successful manipulation and control over their surface chemistry is necessary to control their interactions. The grafting of organic molecular layers onto nanomaterial surfaces has proven to be a valuable strategy to control material properties and their interactions with their surrounding environment. Herein, we present new strategies to covalently bind organic molecules to BP and Ti3C2Tx MXene surfaces. Changes in surface chemistry that occurred during functionalization procedures were monitored and quantified using extensive X-ray photoelectron spectroscopy (XPS) studies. We investigated light-induced grafting of terminal alkenes to BP surfaces using 1H-1H-2H-perfluoro-1-decene (PFD) as a model alkene. Our results for PFD show that the reaction is self-terminating and exhibits monolayer coverages. Additionally, we show that the reaction does not induce significant surface oxidation. We propose a molecular bonding configuration and mechanism for this reaction that aligns with the results of past studies on photochemical functionalization of terminal alkenes to semiconductor and carbon surfaces. We also investigated the generalizability of this reaction using 1-decene and allylpentafluorobenzene. In our studies of these two molecules, we determined that there is preferential adsorption of carbon oxide species to pristine black phosphorus surfaces, which hinders surface functionalization. While this finding presents a challenge towards the application of this chemistry to different organic molecules, it is a valuable insight into the surface reactivity of black phosphorus. We also investigated the thermal grafting of primary alkyl halides to 2D Ti3C2Tx MXene surfaces using 6-bromohexanenitrile (6BHN) as a model molecule. Our XPS data for 6BHN show that while a small amount of spontaneous grafting may occur, the reaction is greatly enhanced with heat and results in sizable surface coverages. Our results suggest that there are likely two grafting modes that occur on the surface: one at the terminal Br-C site at short time scales and the other at the nitrile end of the molecule at longer time scales. Additionally, our functionalization methods were shown to not oxidize the MXene surface. We further investigated the reactivity of primary halides on MXene surfaces using 1-iodooctane and 1-bromooctane. The observed similarities between their reactivity and that of 6BHN indicate that this chemistry can be generalized to other primary iodides and bromides.