Phase controlled synthesis of transition metal carbide nanocrystals by ultrafast flash Joule heating

Bing Deng; Zhe Wang; Weiyin Chen; John Tianci Li; Duy Xuan Luong; Robert A Carter; Guanhui Gao; Boris I Yakobson; Yufeng Zhao; James M Tour

doi:10.1038/s41467-021-27878-1

Phase controlled synthesis of transition metal carbide nanocrystals by ultrafast flash Joule heating

Nat Commun. 2022 Jan 11;13(1):262. doi: 10.1038/s41467-021-27878-1.

Authors

Bing Deng¹, Zhe Wang¹, Weiyin Chen¹, John Tianci Li^{1

2}, Duy Xuan Luong¹, Robert A Carter¹, Guanhui Gao², Boris I Yakobson^{1

2

3}, Yufeng Zhao^{4

5}, James M Tour^{6

7

8

9}

Affiliations

¹ Department of Chemistry, Rice University, Houston, TX, 77005, USA.
² Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA.
³ Smalley-Curl Institute, Rice University, Houston, TX, 77005, USA.
⁴ Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA. [email protected].
⁵ Corban University, Salem, Oregon, 97317, USA. [email protected].
⁶ Department of Chemistry, Rice University, Houston, TX, 77005, USA. [email protected].
⁷ Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA. [email protected].
⁸ Smalley-Curl Institute, Rice University, Houston, TX, 77005, USA. [email protected].
⁹ NanoCarbon Center and the Welch Institute for Advanced Materials, Rice University, Houston, TX, 77005, USA. [email protected].

Abstract

Nanoscale carbides enhance ultra-strong ceramics and show activity as high-performance catalysts. Traditional lengthy carburization methods for carbide syntheses usually result in coked surface, large particle size, and uncontrolled phase. Here, a flash Joule heating process is developed for ultrafast synthesis of carbide nanocrystals within 1 s. Various interstitial transition metal carbides (TiC, ZrC, HfC, VC, NbC, TaC, Cr₂C₃, MoC, and W₂C) and covalent carbides (B₄C and SiC) are produced using low-cost precursors. By controlling pulse voltages, phase-pure molybdenum carbides including β-Mo₂C and metastable α-MoC_1-x and η-MoC_1-x are selectively synthesized, demonstrating the excellent phase engineering ability of the flash Joule heating by broadly tunable energy input that can exceed 3000 K coupled with kinetically controlled ultrafast cooling (>10⁴ K s^-1). Theoretical calculation reveals carbon vacancies as the driving factor for topotactic transition of carbide phases. The phase-dependent hydrogen evolution capability of molybdenum carbides is investigated with β-Mo₂C showing the best performance.

Abstract

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