Physical and electrochemical analyses of spin coated hexaammineruthenium(III)/ Nafion/ITO electrodes for heavy metal detection

• Main Author: Kaw, Kevin Anthony Y.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Electrochemical analysis; Electrodes; Metal detectors; Physics
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/5137
• Institution: De La Salle University

Varying concentrations of hexaammineruthenium (III), [Ru(NH3)6]3+- Nafion®, films were spin coated on indium tin oxide (ITO)-coated glass substrates. The coating solutions were diluted with ethanol, methanol, or isopropanol. The effects of the solvent type, [Ru(NH3)6]3+ or RuHex concentration, and spin rate on the morphology and transport properties of the fabrication electrodes were investigated. Surface micrographs revealed the presence of sub-micron grooves that diminished with increased RuHex concentration. The surface morphology of the electrodes, however, was independent of the spin rate. The viscosity, η, for all 3 solvent types has an inverse power, n = -0.5, proportionality with RuHex concentration, x i.e. {u1D702}={u1D45A}{u1D465}−0.5. Isopropanol diluted solutions were more viscous than ethanol and methanol diluted solutions with the latter being the least viscous. 75mgRuHex/30mL concentrations were prone to become semi-solid gel suspensions. Cyclic voltammetry determined that 50mgRuHex/30mL, isopropanol-diluted solution, spin coated at 2000rpm yielded the best electrode. The optimized electrodes were used to detect lead and cadmium in yellow and pink pigments obtained from commercially available water colors and mask paint.