Work

Formation of Quasi-2D [Mon+1Cn] Layered Structures via Carburizing Metal Films toward Surface Functional Group-Free Molybdenum Carbide MXene Thin Films

Year: 2026

Type: article

Abstract: MXenes have a characteristic quasi-two-dimensional structure composed of covalently bonded transition metal (M) and carbon or nitrogen (X) sublayers, [Mn+1Xn], stacked with an interlayer spacing. Conventional MAX-etched MXenes inevitably have inhomogeneous surface functional groups (Tx), while chemical vapor deposition (CVD) has so far yielded only ultrathin α-Mo2C bulk crystals, failing to form a layered structure. Here, we report a CVD approach that enables the formation of layered [Mon+1Cn] structures through controlled carburization of predeposited Mo films without Tx sources. The resulting films are composed of multiple MXene phases, including Mo2C, Mo3C2, and Mo4C3 layered motifs. Regulated carbon diffusion results in discrete [Mon+1Cn] slabs with a well-defined interlayer spacing. In addition, a signature Tx-free, Mo-exposed surface exhibits enhanced nitrogen reduction reaction (NRR) activity compared with a CVD-grown α-Mo2C film, achieving an NH3 yield of 6.52 μg h–1 cm–2. Given the broad applicability to other MXenes, we anticipate that this work will stimulate further fundamental research and application on MXenes.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.5c23370

Authors: Junhyeok No, Taemin Ahn, Tae-Hwan Kim, Hee Cheul Choi

Institution: Pohang University of Science and Technology

Language: English

Topic: MXene and MAX Phase Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: National Research Foundation of Korea, Samsung