电化学实验报告实验报告.doc

文档介绍：电化学实验报告实验报告
Experimental class on“Fuel Cell and Electrochemistry”
Experiment setup
Equipment: CHI760D electrochemical station
Three electrode system. WE: CE: RE: Saturated Calomel Electrode
Solution: ×10-3mol/L K3 [ Fe (CN)6] + KCl
Lab report
Plot curves of LSV curve, and describe why current changes with sweeping voltage?
Reason: Voltage is a driving force to an electrode reactions, it is concerned with the equilibrium of electron transfer at electrode surface. As the altering
Plot the curves of CV curves with different scan rate;
From the CV curves, fill the table
Scan rate (mV/s)
20
50
100
200
300
400
500
600
Peak current(uA)
Ipc








Ipa
-
-
-
-
-
-
-
-
Ratio of Peak current








Peak voltagE(V)
V1








V2








Peak voltage difference (mV)
71
66
68
72
75
76
79
79
According to the result, describe why curves shows certain trend, and how peak current and peak voltage difference change with scan rate?
Answer: From above data and curve, we can obtain:
At a fixed scan rate : (1).from initial positive voltage to more reductive values, the current begin to flow, then reach a peak ipc and decrease eventually. (2).when voltage moves back, the equilibrium positions gradually converting electrolysis product (Fe2+) back to reactant (Fe3+), the current flow is from the solution species back to the electrode and so occurs in the opposite sense to the forward. The process has another current peak ipa. It has same reason of linear sweep voltammetry.
At different scan rate, the ratio of peak current ipc/ipa is about equal to 1 (—).
At different scan rate, the position of peak voltage do not alter