Stochastically-gated surface processes involving anions in oxidation of Au: time-resolution of processes down to 0.25% coverages and 50 μs time-scales

摘要: Abstract The mechanism of electrochemical surface oxidation noble metals is compared with the by gas-phase oxygen. In presence water, role preadsorbed anions electrolyte and control potential across interface, which possible at electrodes, are discussed, including stochastically-gated oxide film growth. Time resolution initial stages Au in OH species electrodeposited amongst chemisorbed a array become transformed, time, to quasi-2-dimensional phase anion desorption, can be made down 0.25% coverage times ca 100 μs. transformed reducible two well resolved stages, both substantially more stable, as measured Gibbs energies for their reduction, than 2-D from they originated. growth decrease reversibly deposited OH's these originate, each logarithmic time This behaviour treated terms time-dependent changes surface-potential component metal—solution pd due OH—M O—M place-exchange. treatment shown lead direct law having characteristic agreement experiment.