Termination-Property Coupling via Reversible Oxygen Functionalization of MXenes

作者：James L. Hart, Kanit Hantanasirisakul, Yury Gogotsi, Mitra L. Taheri · 发表于：ACS Nanoscience Au · 年份：2022 · DOI：10.1021/acsnanoscienceau.2c00024 · 被引用次数：26 · 研究领域：MXene and MAX Phase Materials、Advanced Memory and Neural Computing、2D Materials and Applications

High Resolution Image Download MS PowerPoint Slide MXenes are a growing family of 2D transition-metal carbides and nitrides, which display excellent performance in myriad of applications. Theoretical calculations suggest that manipulation of the MXene surface termination (such as ═O or −F) could strongly alter their functional properties; however, experimental control of the MXene surface termination is still in the developmental stage. Here, we demonstrate that annealing MXenes in an Ar + O 2 low-power plasma results in increased ═O functionalization with minimal formation of secondary phases. We apply this method to two MXenes, Ti 2 CT x and Mo 2 TiC 2 T x (T x represents the mixed surface termination), and show that in both cases, the increased ═O content increases the electrical resistance and decreases the surface transition-metal’s electron count. For Mo 2 TiC 2 O x, we show that the O content can be reversibly altered through successive vacuum and plasma annealing. This work provides an effective way to tune MXene surface functionalization, which may unlock exciting surface-dependent properties.