For my CV experiments it is always very difficult for me to clean the Electrodes. How can I clean the electrodes (Gold and Glassy Carbon) without damaging their surface?
for alumina: alumina, sonication or in 1M H2SO4 solution ten cycle 50mV/s CV from -1,2 to + 1,2 V
for gold: wait in 0,1M Pi buffer including 10M H2O2 solution for ten minutes. or pirhana solution 2 minutes.
Instead of alumina, I usually use diamond nanopowder (Aldrich, 1 microm) diluted with water on microcloth pads. Then I ultrasonically rinse in CH3CN for 5 min and in the operative solvent for other 5 min.
After cleaning with wet and dry fitler paper and rinsed the electrodes in 1 M HCl4 solution for application of twenty cycle 30 mV/s from + 1.2 V to -1.2 V and then wash with distilled water
Fine-polished with 0.3 and 0.05 µm alumna slurry on microcloth pads and then rinsed with doubly distilled water. Then dry it.
Glassy carbon:
alumina,
sonication or
in 1M H2SO4 solution ten cycle 50mV/s CV from -1,2 to + 1,2 V
You can be used two method for this problem.
Fist you can polished your electrode with alumina powder.
second you can used cyclic voltammetry method. You must input electrode in 0.5 H2SO4 and run cyclic voltammetry for 20 scan in the range -0.5 to 1.5 V.
But i suggest to you that done two method in same time. Firstly polish and then cyclicvoltammetry method
1 part of H2O2 (30 %) + part of H2SO4 (96-98%). T ~ 70-90, 3-5 min.
I prefer only polishing and sonication. Any electrochemical pretreatment involving high potentials could result in electrode oxidation and, therefore, modification of the glassy properties. Although, slight oxidation can improve the electrochemical signals in several redox systems.
Polishing should work. There is a time I soaked it in an acidic media and the next day, there was no electrode. That means that every time you expose them to strong chemicals, little damage is done. Besides, depending on the design, these chemicals may damage binders used to package it.
i am using GC since it is known from 1985-- do not use hard polising - wit will create crevices and electrolyte would enter- pits will be formed
the review cited above works very well and also polishing and later sonication in HNO3 for 5 min is very fine.
why nitric acid? do not complicate the surface- difficult to remove nitric acid
Hi
Please Follow these steps
1- soft polishing with 1 , 0.3 and 0.05 micrometer of alumina for some minutes
2- ultrasonic the tip of GCE in ethanol and distilled water for 15 min, respectively
3- cyclic voltametery test for 20 times with a solution of 0.5-1 M H2SO4 in the potential range of (-1 to 1 V) and scan rate of 50 mV/s
4- cyclic voltametery test for 10 time with PBS 1X and ferrosianide solution with concentration of 4 mM.
5- the peaks separation should be lower than 80 mV. if it is not, repeat the steps again
Good Luck
Do not sonicate the electrode. The contact inside is made by silver epoxy and is prone to break upon sonication.
Do not ultrasonicate the electrode.Electrode polishing kits are also available. you can use alumina powder instead. Take a small amount of alumina powder on the cloth provided in the kit. add 2-3 drops of DI water. and clean the electrode gently.
my GCE is contaminated how do i clean it beside polishing with alumina powder
I have lot of problems with gold tip for RDE
HERE is the procedure i find out to clean it properly
EC cleaning is done by sweeping from 0 to 1.7 V with scan rate of 100mV/s 30 cycles in 0.1 M H2SO4 for stripping the speicies deposited in the surface
polishing with
higher to lower size of alumina slurries in brown cloth
if scratches still there
use diamond slurry on nylon pad
and then again with alumina
i hope it will work
1) preparing stock solutions (0.01 M potassium ferric cyanide + 0.1 M KCL solution)
2) clean the electrode with 0.3 and 0.05 micrometer of alumina slurry for 2 minutes
3) Then washed with water for several times
4) Touch up with tissue paper
5) Then fixed working electrode
6) Record the CV between -0.2 V to 0.6 V with scan rate at 10 mV (0.01 M potassium ferric cyanide + 0.1 M KCL solution)
7) peaks separation should be lower than 80 mV. otherwise you should clean the electrode util get the peak separation below 100 mV
Do we need to polish and then clean? Or clean and then polish wash with water and use it?
1) Clean the electrode through water to remove the catalyst ink coating,
2) Then polish the electrode with alumina slurry and wash by water for numerous time.
a. soft polishing with 1 , 0.3 and 0.05 um of alumina slurries
b. bath the GCE surface ultrasonically in the Acetone and ethanol solution for 5 mins
c. Purge with nitrogen gun and keep them air tight for further use
Polish the GCE with 0.05 μm alumina slurry, rinse with deionized water, and sonicate in ultrasonic bath for 5 min.. Dry the electrode under a stream of pure nitrogen. Its ready for further use.
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