Suchergebnisse

Antimonene, a novel group 15 two-dimensional material, is attracting great attention due to its outstanding physical and chemical properties. Despite its thermodynamic stability, the pronounced covalent character of the interlayer interactions imposes severe limitations on its exfoliation into mono- and few-layer. Here, we develop a systematic study of liquid phase exfoliation (LPE) with the aim to optimize antimonene production in terms of concentration and dimensional anisotropy, investigating the most relevant experimental factors affecting the exfoliation: pre-processing of pristine antimony, solvent selection based on Hansen solubility parameters and ultrasound conditions. Moreover, exhaustive characterization by means of turbidimetry, XRD, Raman spectroscopy, XPS, AFM, SEM, XEDS and TEM has been carried out. Indeed, we achieved concentration values of ca. 0.368 g L−1 (∼yield of 37 wt%), up to ∼30 times higher compared to the highest value so far reported, with ca. 50% of the nanolayers with heights between 2 and 10 nm and lateral dimensions in the 40–300 nm range. Furthermore, it has been demonstrated that the yield of the process can be enhanced up to ∼90 wt% by recycling the sediment to perform a maximum of 7 cycles. Moreover, we have illustrated the usefulness of this approach by characterizing the electrochemical behaviour of antimonene as a catalyst for the hydrogen evolution reaction (HER). This study provides important insights into the LPE and electrochemical properties of antimonene, allowing its large-scale production and paving the way for its application in fields of utmost importance such as energy storage and conversion or catalysis ; The work has been supported by the European Union (ERC-2018-StG 804110-2D-PnictoChem to G. A.) and the Spanish MICINN (MAT2016-77608-C3-1-P and PCI2018-093081) and MINECO (Structures of Excellence María de Maeztu MDM-2015-0538 and FIS2017-82415-R). G. A. acknowledges support from the Generalitat Valenciana (CIDEGENT/2018/001) and the Deutsche Forschungsgemeinschaft (DFG; FLAG-ERA AB694/2-1). R. S.-G. acknowledges the Spanish MINECO for an FPU fellowship. J. J. P. and W. S. P. acknowledge financial support from the Spanish MINECO through Grant FIS2016-80434-P, the Fundación Ramón Areces, and the European Union Seventh Framework Programme under FLAG-ERA agreement No. 604391. W. S. P. was funded by the CNPq Fellowship programme (Pós-doutorado júnior) under grant 405107/2017-0 and acknowledges the computer resources and assistance provided by the Centro de Computación Científica of the Universidad Autónoma de Madrid and the RES