Generation of MoS2 quantum dots by laser ablation of MoS2 particles in suspension and their photocatalytic activity for H2 generation

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2016-08, Vol.18 (8), Article 240
• Main Authors: Baldoví, Herme G., Latorre-Sánchez, Marcos, Esteve-Adell, Iván, Khan, Anish, Asiri, Abdullah M., Kosa, Samia A., Garcia, Hermenegildo
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Inorganic Chemistry; Lasers; Materials Science; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Research Paper
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-016-3540-9

MoS 2 quantum dots (QDs) have been obtained in colloidal suspensions by 532 nm laser ablation (7 ns fwhp/pulse, 50 mJ/pulse) of commercial MoS 2 particles in acetonitrile. High-resolution transmission electron microscopy images show a lateral size distribution from 5 to 20 nm, but a more homogeneous particle size of 20 nm can be obtained by silica gel chromatography purification in acetonitrile. MoS 2 QDs obtained by laser ablation are constituted by 3–6 MoS 2 layers (1.8–4 nm thickness) and exhibit photoluminescence whose λ PL varies from 430 to 530 nm depending on the excitation wavelength. As predicted by theory, the confinement effect and the larger periphery in MoS 2 QDs increasing the bandgap and having catalytically active edges are reflected in an enhancement of the photocatalytic activity for H 2 generation upon UV–Vis irradiation using CH 3 OH as sacrificial electron donor due to the increase in the reduction potential of conduction band electrons and the electron transfer kinetics.