la061299n_si_001.pdf (208.64 kB)
Cathodic Electrodeposition of Mixed Molybdenum Tungsten Oxides from Peroxo-polymolybdotungstate Solutions†
journal contributionposted on 2006-12-05, 00:00 authored by Lilia Kondrachova, Benjamin P. Hahn, Ganesh Vijayaraghavan, Ryan D. Williams, Keith J. Stevenson
Mixed molybdenum tungsten trioxide films of varying stoichiometry (MoxW1 - xO3, 0 < x < 1) were prepared by cathodic electrodeposition on indium tin oxide (ITO)-coated glass substrates from aqueous peroxo-polymolybdotungstate solutions. Electrochemical quartz crystal microbalance (EQCM), cyclic voltammetry, and chronocoulometry were used to gain insight into the electrodeposition mechanism. The compositional and structural properties were characterized for MoxW1 - xO3 films deposited at intermediate potentials (−0.35 V vs Ag/AgCl) and sintered at 250 °C using energy-dispersive spectroscopy, X-ray diffraction, and Raman spectroscopy. These studies reveal that films consist of homogeneously mixed MoxW1 - xO3, with an enriched Mo content ranging in composition from 0.4 < x < 0.7 depending upon the mol % Mo present in the deposition solution. Chronoamperometry and spectroelectrochemical measurements were conducted to estimate lithium ion diffusion coefficients and coloration efficiencies for the mixed metal oxide films in 1 M LiClO4/propylene carbonate. The subtle interplay between structural and compositional properties due to the uniform mixing of Mo and W oxide components shows that electrochromic and lithium ion transport properties are moderately enhanced relative to those of single-component WO3 and MoO3 and demonstrate improved structural stability over pure MoO3 polymorphs during electrochemical cycling.
WOMoxWdeposition solutionMo contentcathodic electrodepositionindium tin oxidespectroelectrochemical measurementselectrochemical cyclingRaman spectroscopyestimate lithium ion diffusion coefficientsMixed Molybdenum Tungsten OxidesEQCMgain insightelectrodeposition mechanismcoloration efficienciesITOElectrochemical quartz crystal microbalanceMoO 3MoO 3 polymorphsmetal oxide filmslithium ion transport propertiesCathodic ElectrodepositionW oxide components