Design of Atomic Ordering in Mo2Nb2C3T x MXenes for Hydrogen Evolution Electrocatalysis

• Published in: Nano letters 2023-02, Vol.23 (3), p.931-938
• Main Authors: Wyatt, Brian C., Thakur, Anupma, Nykiel, Kat, Hood, Zachary D., Adhikari, Shiba P., Pulley, Krista K., Highland, Wyatt J., Strachan, Alejandro, Anasori, Babak
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.2c04287

The need for novel materials for energy storage and generation calls for chemical control at the atomic scale in nanomaterials. Ordered double-transition-metal MXenes expanded the chemical diversity of the family of atomically layered 2D materials since their discovery in 2015. However, atomistic tunability of ordered MXenes to achieve ideal composition-property relationships has not been yet possible. In this study, we demonstrate the synthesis of Mo2+αNb2−αAlC3 MAX phases (0 ≤ α ≤ 0.3) and confirm the preferential ordering behavior of Mo and Nb in the outer and inner M layers, respectively, using density functional theory, Rietveld refinement, and electron microscopy methods. We also synthesize their 2D derivative Mo2+αNb2−αC3T x MXenes and exemplify the effect of preferential ordering on their hydrogen evolution reaction electrocatalytic behavior. This study seeks to inspire further exploration of the ordered double-transition-metal MXene family and contribute composition-behavior tools toward application-driven design of 2D materials.