화학공학소재연구정보센터
Applied Surface Science, Vol.313, 498-503, 2014
TEOS-assisted synthesis of porous MoS2 with ultra-small exfoliated sheets and applications in dye-sensitized solar cells
Exfoliated MoS2 of ultra-small sheets were for the first time synthesized by embedding the precursors ((NH4)(6)Mo7O24 center dot 4H(2)O and thiourea) inside the hydrogel of the activated silicic acid (calculated as SiO2) which was obtained from hydrolysis of tetraethylorthosilicate (TEOS). It was found that the added molar ratio of SiO2/MoS2 = 10.0 can effectively be used as templates to prohibit the growth of MoS2. Analysis of TEM, Raman spectra, XRD and BET reveals that the added TEOS plays a vital role in forming of exfoliated sheets and obtaining high specific surface area (101.6 m(2)/g) in the resultant products. The prepared exfoliated sheets of MoS2 were employed as counter electrodes (CEs) materials for dye-sensitized solar cells (DSSCs). The electrochemical analysis (cyclic voltammograms, electrochemical impedance spectroscopy) indicates that the porous MoS2 sheets CEs possess lower charge transfer resistance and a higher electrocatalytic activity in reducing I-3(-) to I- compared to the flower-shaped MoS2 synthesized with less amount of the added TEOS. The DSSCs based on the porous MoS2 sheets CEs was demonstrated to achieve a high power conversion efficiency of 6.35% which is comparable to that of Pt CEs (6.19%). (C) 2014 Elsevier B.V. All rights reserved.