Unveiling the Interfacial and Structural Heterogeneity of Ti3C2Tx MXene Etched with CoF2/HCl by Integrated in Situ Thermal Analysis

Cody B Cockreham; Xianghui Zhang; Jeffrey A Eakin; Martinus Dewa; Houqian Li; Nan Li; Junming Sun; Su Ha; Cornelius F Ivory; Yong Wang; Hongwu Xu; Di Wu

doi:10.1021/acsami.1c10021

Unveiling the Interfacial and Structural Heterogeneity of Ti₃C₂T_x MXene Etched with CoF₂/HCl by Integrated in Situ Thermal Analysis

ACS Appl Mater Interfaces. 2021 Nov 10;13(44):52125-52133. doi: 10.1021/acsami.1c10021. Epub 2021 Aug 13.

Authors

Cody B Cockreham^{1

2

3}, Xianghui Zhang^{1

2}, Jeffrey A Eakin², Martinus Dewa⁴, Houqian Li², Nan Li⁵, Junming Sun², Su Ha², Cornelius F Ivory², Yong Wang^{2

6}, Hongwu Xu³, Di Wu^{1

2

7

8}

Affiliations

¹ Alexandra Navrotsky Institute for Experimental Thermodynamics, Washington State University, Pullman, Washington 99164, United States.
² The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States.
³ Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
⁴ School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, United States.
⁵ Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
⁶ Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
⁷ Department of Chemistry, Washington State University, Pullman, Washington 99164, United States.
⁸ Materials Science and Engineering, Washington State University, Pullman, Washington 99164, United States.

PMID: 34387989
DOI: 10.1021/acsami.1c10021

Abstract

Ti₃C₂T_x MXene is a member of the recently discovered two-dimensional early transition metal carbide and nitride family of MXenes with potential applications in energy storage and heterogeneous catalysis at elevated temperatures. Here, we apply a suite of in situ techniques to probe Ti₃C₂T_x MXene's thermal evolutions, including in situ X-ray diffraction (XRD), in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and integrated thermogravimetry-differential scanning calorimetry-mass spectrometry (TG-DSC-MS). In light of this set of in situ investigations, we find heterogeneity in the layering of Ti₃C₂T_x MXene revealed only at higher temperatures. Our findings present behavior up to 600 °C, particularly interlayer water and -OH surface end-capping groups. In one group of layers, their interlayer spacing shrinks as water deintercalates, but the other group of layers unexpectedly shows no change in the interlayer spacing. This is strong evidence that intercalants act as guest pillaring agents in the latter layering group, which stabilize these layers at higher temperatures while keeping the interlayer space accessible.

Keywords: 2D layered materials; MXenes; cobalt fluoride; heterostructure; in situ XRD; interlayer heterogeneity; thermal analysis.

Publication types

Review