Impacts reveal and quantify monolayer adsorption on single alumina particles

A particle impact method is used to quantify adsorption of redox active species on single insulating particles by simulation of individual spike transient, circumventing the complexity of measurements with ensembles of particles. For catechol, anthraquinone and chloranil molecules and the ferrocene moiety of poly(vinylferrocene) adsorbed on alumina, the surface coverages are found to be (3.0 ± 0.9), (1.5 ± 1.4), (2.7 ± 1.7) and (2.1 ± 0.7) × 10–10 mol cm–2, and the charge diffusion coefficients are found as (2.5 ± 0.5), (7.9 ± 4.0), (0.4 ± 0.2) and (2.4 ± 0.8) × 10–6 cm2 s–1, respectively.