Facile hydrothermal synthesis of MoS2 nano-sheets with controllable structures and enhanced catalytic performance for anthracene hydrogenation

• Published in: RSC advances 2016-01, Vol.6 (75), p.71534-71542
• Main Authors: Li, Min, Wang, Donge, Li, Jiahe, Pan, Zhendong, Ma, Huaijun, Jiang, Yuxia, Tian, Zhijian
• Format: Article
• Language: English
• Subjects: Anthracene; Catalysts; Catalytic activity; Crystallinity; Crystallization; Hydrogenation; Molybdenum disulfide; Nanostructure
• ISSN: 2046-2069
• DOI: 10.1039/c6ra16084k

MoS 2 nano-sheets with controllable structures were prepared using a hydrothermal method. Effects of crystallization time, temperature and pH of the precursor solution on the structures, components and morphologies of MoS 2 nano-sheets were investigated. MoS 2 nano-sheets were characterized using XRD, Raman, elemental analysis, TG/DTG, SEM, and HRTEM. The characterization results show that intercalated MoS 2 , intermediate MoS 2 with intercalated and semi-crystallized structures, and well crystallized hexagonal MoS 2 (denoted as 2H-MoS 2 ) were prepared by varying crystallization conditions, especially crystallization time. Intercalated MoS 2 possesses rich active sites and poor crystallinity. 2H-MoS 2 demonstrates high crystallinity but few active sites. As a transition structure during the crystallization process from intercalated MoS 2 to 2H-MoS 2 , intermediate MoS 2 simultaneously possesses rich active sites and good crystallinity. The possible growth mechanism of MoS 2 nano-sheets in the hydrothermal process was proposed. The catalytic activities of MoS 2 nano-sheets with various structures were evaluated by anthracene hydrogenation. The evaluation results show that intermediate MoS 2 exhibits optimized catalytic activities of anthracene hydrogenation, which can be ascribed to the abundant active sites and desired stability of intermediate MoS 2 . This work may provide theoretic guidance for creating active sites and tuning catalyst structure for the controllable synthesis of layered transition metal sulfides with high catalytic activities. Intermediate MoS 2 with rich active sites and desired stability was controllably synthesized and exhibits optimized catalytic activity of anthracene hydrogenation.