Abstract
In this work, we proposed a two-phase hydrothermal synthesis approach to fabricate high-curvature bulk surface with engineered in-plane defects. Organic or supercritical solvents were introduced as a second immiscible media to alter MoS2 hydrothermal growth. Two mixing scenarios, depending on the ratio of organic solvent to aqueous solution. In the case of the organic solvent isolated by aqueous solution, the growing slabs change its original direction when getting contact with the organic droplets. In the scenario that aqueous droplets dispersed in organic solvent, MoS2 slabs grow along the curved interfaces of aqueous droplets. Experimental results showed that the curved basal planes were generated in the two cases and more curvatures were introduced in the second phase under adequate mixing energy. Higher curvature degree led to a better catalytic performance. Compared to decalin, supercritical heptane that can facilitate the dispersion of the precursor-containing aqueous solution into homogeneous nano-size reaction cells, showed a great capacity to generate highly curved slabs. MoS2 synthesized with supercritical solvent exhibits the highest activity among the investigated catalysts. The catalysts were characterized by SEM, XRD, XAFS, TPR and nitrogen adsorption analysis. The results were proved by the theoretical calculations that the formation energy (Eform) of sulfur vacancy (VS) on curly structure possesses a reduction of 0.19 eV comparing with planar MoS2 monolayer. The curved structure can facilitate the surface VS generation by depopulating the occupied bonding states of corresponding Mo-S bonds. This work provides an effective approach to create basal defects on the MoS2 to promote its catalyst activity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.