Electrodeposition of MoS<sub>2</sub> from Dichloromethane
Shibin Thomas, Danielle E. Smith, Victoria K. Greenacre, Yasir J. Noori, Andrew L. Hector, C.H. de Groot, Gillian Reid, Philip N. Bartlett
Abstract
The electrodeposition of MoS 2 from dichloromethane (CH 2 Cl 2 ) using tetrabutylammonium tetrathiomolybdate ([N n Bu 4 ] 2 [MoS 4 ]) as a single source precursor is presented. The electrodeposition of MoS 2 from CH 2 Cl 2 requires addition of a proton donor to the electrolyte and trimethylammonium chloride (Me 3 NHCl) was used for this purpose. Electrochemical Quartz Crystal Microbalance (EQCM) experiments have been employed for a detailed study of the electrochemical mechanism and to study the role of the proton donor. EQCM reveals cathodic electrodeposition of MoS 2 and anodic deposition of MoS 3 as well as an additional corrosion process where the deposited MoS 3 strips back into solution. The electrodeposited MoS 2 films are amorphous in nature. All the films were found to be homogeneous in composition across the electrode area and to be reproducible between experiments. Annealing of the as-deposited films under a sulfur atmosphere results in crystalline MoS 2 as confirmed by energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy and X-ray diffraction. The deposited films were smooth and planar, as observed with scanning electron microscopy (SEM), indicating a layer-by-layer growth typical of transition metal dichalogenides.