Quick Start Guide for CHI-400A
Contents
1. Untitled osme TE t 4fes im fr e HA Bald ri Sample Interval sec 01 Run Time sec occ 400 Quiet Time Scales during Sensitivity AMV I Auniiary Signal Recording When SI gt 0 005 s I High Resolution ADC if SI gt 0 0025 I QCM On When SI gt 0 005 s The output of the run can then be analyzed as described above Saving Data Each project can be saved simply by clicking File gt Save As and choosing a destination The file will be saved as a bin type that is only readable by the CHI program If you would like to be able to manipulate your data or open the files on another program such as Excel then you must first save it as a bin and then use the option in the File menu to convert the file to text This text file can then be manipulated however you like For instructions on how to import it to Excel please see the QCM write up on the Ward Group website2. the electrode surface Choosing a Method and Setting Parameters In order to chose an experiment to run press the button circled below and the dialog box shown will appear ec Untitled E Untitled Electrochemical Techniques OK a Cyclic metr meran e y Linear Sweep Voltammetry Help Staircase Voltammety Tafel Plot Chronoamperometry Chronocoulometry Differential Pulse Voltammetry Normal Pulse Voltammetry Differential Normal Pulse Voltammetry Square Wave Voltammety AC Voltammetry 2nd Harmonic A C Voltammetry Amperometric i t Curve Differential Pulse Amperometry Double Differential Pulse Amperometry Triple Pulse Amperometry Bulk Electrolysis with Coulometry Hydrodynamic Modulation Voltammetry Sweep Step Functions Multi Potential Steps Chronopotentiometry Chronopotentiometry with Current Ramp Multi Current Steps Potentiometric Stripping Analysis Open Circuit Potential Time Quartz Crystal Microbalance I7 Polarographic Mode Once you have chosen which experiment you would like to run the parameters for the experiment must be set The parameters box may appear once you select an experiment If it does not it can be opened with the parameters menu button gt ec Untitled Each method has its own specific parameters which must be set before running an experiment If you wish to perform another run with different parameters simply click the parameters button again and make the nec
3. V 5e 6 Current 1e 5A aL I LA a a a Ln a a Va a a LAL l 0 80 0 70 0 60 0 50 0 40 0 30 0 20 0 10 0 Potential V E 0 5394V i 4 544e 6A Containing 0 1M KNO as well as 0 01M K Fe CN 6 this illustrates the oxidation and reduction of a solvated species in this case F Fe due to a varying potential 4 0 F re a ce col a a Ra A MO Sa Ye VONE SC YC ae ea ee ee re ace ve ea E F May5 2008 13 10 34 3 54 Tech CV 46 J File KFeCN 5 5 bin l F Init E V 0 8 2 5 High E V 0 8 204 Low E V 0 4 Init P N N 1 54 Scan Rate V s 0 1 Segment 10 Smpl Interval Y 0 001 Quiet Time s 2 Sensitivity A V 1e 5 Current le 5A 3 0 E SAE E l 0 80 0 70 0 60 0 50 0 40 0 30 0 20 0 10 0 Potential V Cu Deposition Copper deposition can be used to analyze the active area of the EQCM crystal This is done by converting the measured current to number of ions deposited and plugging the mass change into the Sauerbrey equation The average of several runs should be used to obtain more accurate values of A for use in further calculations In order to deposit copper the potential should be held at around 0 3V While applying this constant potential the change in frequency must also be recorded using the QCM In order to perform this technique we use a solution of about 0 1M KNO and 0 01M CuSO and run an Amperometric i t curve with the QCM on box checked ec
4. Quick Start Guide for CHI 400A This guide is meant to be a brief overview of functions and features If you would like to use more features or have any questions about the operation of the instrument please see the user s manual Tips If you receive an overflow error in any experiment simple adjust the sensitivity for the run in the parameters control panel as described below Electrodes are assigned in the following manner green working GSE red counter and black auxiliary In most experiments the auxiliary electrode is not used When the QCM cell is used the working electrode is the exposed side of the crystal and the green alligator clip need not be attached Be certain to store the reference electrode in the container provided submerged in 3M KCI so that it does not dry out Once the QCM is turned on especially in the presence of a liquid medium it may take half an hour or more to come to equilibrium and give a steady reading Please take this into account when planning experiments When running longer experiments equilibration is more important as the drift in frequency may increase over time Be certain to polish the button electrodes before use to make sure that you have a good connection and that no contaminants are introduced in to the system If readings still seem off after polishing run multi potential steps from 0 6V to 1 4V with several cycles This will evolve Hydrogen and Oxygen which will scrub
5. essary changes The QCM EQCM Cell When running any experiment using the QCM EQCM cell and it is important to make sure that the cell is configured to use the correct frequency Other settings specific to experiments may also be adjusted in the following way Click Control in the top bar and select Cell Ensure that the correct crystal frequency is listed Cell Control Control Level of Stir Line OK ok Cancel pws Help ActiveHigh Active Low Immediate Stir Ref Crystal Frequency Hz 1e 007 SMDE Drops Before Run Immediate Purge Stabilizing Capacitor Purge Time sec MV Automatic Setting Purge C On Off l 4 Electrodes Stir Between Run Immediate Cell On Mercury Drop Collection IV Purge Between Run Potential V Time sec V Stir and Purge Simultaneously I Test with Internal Dummy Cell Cell On Collect Cell On Between Runs IV Retum to Init E after Run Taking drift issues into consideration it is also a good idea to select the cell on between runs checkbox to keep the crystal oscillating at all times Sample CV s Containing only 0 1M KNO supporting electrolyte with Pt working counter and AgCl Ag reference electrodes 2 9 4 4 tt ts Apr 29 2008 13 19 48 i Tech CV 1 64 oe File CV KNO3 new bin Init E Vv 0 High E V 0 8 Low E V 0 Init P N P Scan Rate V s 0 1 Segment 10 Smpl Interval Y 0 001 Quiet Time s 2 Sensitivity A
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