Electroanalytical Chemistry Lecture书 An Introduction to electro chemica Method
General Appro ach to Electrochemical Experiments ◆ Identify assumptions D佈mn-m8ta忽rt Identify suitable boundary co nd itions ◆S口 Ive linear dittusion equation (FICKs2nd lay 一以eL学門Cet念rT Substitute solution into Nernst-planck equation and solv e
Experiments are Categ orized By the excitation wayeform -2 kinds yariation in单 plied P otentia〔E〕 ◆Step Ramp variat ion in Applied Current () ◆ the response waveform voltammetry (I vS E
Potential Step Methods ◆ Chronoam peron etry C R色 =ponse ● Chronocoulom etry 〔CC E : spg ◆ Pulse woit am m etry 一 Response:i够.E Alluse potartialstap exc ttion All in quiescent splution
Chronoamperometry(Ca) Exciation. Solution: Cottrell equation nFd T ti◆E1- redox activit Resporse E2:|E|≥E I-step size: determ ined perim enta‖y time Stationary 1, quiescent soution
Chronoamperometry (cont/d) ◆R已pn念e Comtectnrl Cottrell plot 100s ,t惶 Doble l好rer Intercept: 0 Charging 2(≤50 Slop nFAD12CAT12 tlr 工tm hittIng
Chronoamperometry (cont/d) ◆ teatime Response horizontal plot Lost t iz .1g T est for difusion司 5pe=-05 control log ivs. log t Logt
Applicati ons of Chronoamperometry ◆ Determ ination of: D + kineticsreaction mechanism Double pote ntial ste p G币t园郊ec旧es, probe fate
Applications of Chronoamperometry Determine A of ele ctrode using primary ele ctrochemical stand ard Ferrocene f errocini以 Fe〔CN534 Ru(NHaia2+ 2 Use ele ctrode to measure Do d p for analyte re dox couple
EXAMPLE: Diffusion in Sol Gel glasses ReferenceA R. howells Pj Zambrano; M. M. Collison(Kansas State) Ana.Chem.2000.72.5265-71 + Interest: Sol-gel: analyte/silica gel 3冂s atalysts
