Theory of staircase voltammetry for simple electrode reactions

Stalrcase voltammetry has been proposed as an electroanalyticaltechnlque which allows the obsarvatlon of pure faradaiccurrent. In the present paper the staircase wave form Isregarded as a hear sweep wlth a superlmposed perlodlcsawtooth perturbatlon. Wlth the sawtooth represented by aFowler serles, under sultable condltlons the theory of theclassical ac voltammetry can be applled. In thls way theoutput due to the sawtooth perturbatlon can be computed andits zeroes identified. The current at these polnts, whose locationdepends on electrode potentlal and klnetlc parametersof the charge transfer, Is that of the underlylng linear sweep,unaffected by the charging current. We describe a methodto flnd these points In an experimental stalrcase voltammogram,without knowlng a prior1 the klnetlc parameters of theprocess. These points descrlbe completely the linear sweepvoltammogram, so much so that It can be drawn by trlgonometriclnterpolatlon.