We have illustrated a fuel cell electroplating method to deposit nano gold particles on the high-surface area carbon cloth. The gold-electroplated carbon cloth exhibited greater performance in serving as a cathode for hydrogen peroxide fuel cells. Due to the specific mechanism of menbraneless hydrogen peroxide fuel cells, researchers are currently based on developing noble metal complexes as electrodes and improving the sensitive area of these electrodes by employing nanotechnology and coordination chemistry.
In our research, we not only proposed the electroplating method for fabrication high-surface area for the electrodes, but also found a very important role of pH in fuel cell, which remains neglected in the previously reported research. There are a lot of techniques that can be used for fabricating these nanoscale electrodes, such as physical or chemical evaporations. However, these methods are very expensive as well as time-consuming.
As electrodes now need accuracy in thickness, electroplating is a very promising method for these electrodes. To begin electroplating gold on carbon fiber cloth, gather the reagents required for electroplating, which include chloroauric acid, potassium chloride, hydrochloric acid, and deionized or DI water. In a clean beaker, prepare an 80-milliliter solution by combining appropriate amounts of all the reagents in DI water.
After that, seal the container and stir the solution for 15 minutes to prepare the plating solution. Next, set up the electroplating material carbon cloth and plating solution in the electrochemical station, or ES, and immerse the counter and reference electrodes into the plating solution. After starting the ES, set the program to chronoamperometry method and set the electroplating circles at 800, 1600, 2400, and 3200 circles.
Then, run the program. Once the electroplating is done, close the ES.After packing the reagents, collect the gold electroplated carbon fiber cloth. Immerse the cloth in DI water three times to remove the solution residues and place it on a glass surface for drying in the air.
During electroplating, the portion of the carbon fiber cloth that was clamped remains unplated. Cut those unplated parts of the gold electroplated carbon fiber cloth. Then, using a ruler, measure the length and breadth of the electroplated fiber cloth to calculate current by power densities.
The carbon fiber cloth color changed from black to golden yellow after electroplating, confirming the effective deposition of gold on it. Successful electroplating was further verified by X-ray diffraction and scanning electron microscopy or SEM imaging. The SEM images indicated a uniform dispersion of gold nanoparticles across the carbon fiber cloth.
Remarkably, the original three-dimensional porous structure of the carbon fiber remained well-preserved post-electroplating. The color transition from black to gold intensified as the number of electroplating cycles increased, suggesting an increase in the volume of gold deposition. The same was confirmed from the SEM images.
To begin, prepare two sets of hydrogen peroxide solutions, one set of solutions for pH gradient composed of 1 molar hydrogen peroxide having variable pH, while the other set for concentration gradient composed of varying concentrations of hydrogen peroxide at pH 1. To characterize the fuel cell or FC performance by the electrochemical station or ES, first, wash the nickel foam and gold electroplated carbon fiber cloth electrodes with deionized water two times and place them aside. For obtaining the open circuit potential or OCP data, use nickel foam as both RE and CE and the gold electroplated carbon fiber cloth as the working electrode or WE.Next, add the appropriate hydrogen peroxide solution previously prepared to the test beaker.
Connect electrodes to the ES before turning on the system. Set the program to open circuit potential time method, the runtime to 400 seconds, the sample interval to 0.1 seconds, the high E limit to 1 volt, and the low E limit to 1 volt. Run the program to measure the data, after that, close the program.
To test the output performance of FC based on OCP data, set the program to LSV, OCP as initial E, and 0 volt is final E, corresponding to the conditions of open circuit and short circuit respectively. Run the program to collect the data. Once done, close the program.
Wash the beaker and electrodes before adding other required solutions for specific tests. After the experiments are complete, store the washed electrodes in a glass or plastic box. The OCP durability of the FC determined that different hydrogen peroxide concentrations with a pH of 1 indicated that, in all cases, the electrode could operate continuously for at least 400 seconds without significant degradation.
The FC performance was found to be sensitive to the solution pH. Under extreme acidic and basic conditions, the power output of the FC was relatively high.
