Unknown

Dataset Information

0

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


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-MoC1-x and η-MoC1-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.

SUBMITTER: Deng B 

PROVIDER: S-EPMC8752793 | biostudies-literature |

REPOSITORIES: biostudies-literature

Similar Datasets

| S-EPMC8490403 | biostudies-literature
| S-EPMC9674293 | biostudies-literature
| S-EPMC10795059 | biostudies-literature
| S-EPMC4532880 | biostudies-other
| S-EPMC6467806 | biostudies-literature
| S-EPMC10687867 | biostudies-literature
| S-EPMC8588312 | biostudies-literature
| S-EPMC10728626 | biostudies-literature
| S-EPMC5484998 | biostudies-literature
| S-EPMC9772412 | biostudies-literature