THE ELECTRODEPOSITION OF AMORPHOUS MOLYBDENUM SULFIDE

The electrochemical oxidation of an aqueous solution containing ammonium tetrathiomolybdate at a tin-oxide-coated glass electrode produces a material with MoS3.8 Stoichiometry which consists of amorphous molybdenum trisulfide and elemental sulfur. The nucleation and growth of amorphous molybdenum sulfide have been studied by cyclic voltammetry and potential step experiments. The effect of the ammonium tetrathiomolybdate concentration and solution pH on the current-time transients has been investigated. The analysis of the early part of the transients was carried out using the current-time relationships developed for metal deposition. Our data analysis indicated that film formation occurred by instantaneous nucleation and three-dimensional growth. Subsequently, the formation of bulk film is limited by diffusion or kinetics at low or high MoS42- concentrations respectively.