Hi Steve,

I'd like to address your question in a retrogressive manner with the portion where you highlighted that, the electrochemical measurement without the electrochemical deposition of palladium nanocrystals (Pd-NCs) resulted in a similar cyclic voltammogram (CV), only that the SPE-modified Pd-NCs has a higher maximum current. Indeed, the increase in the maximum peak current can be ascribed to the deposited Pd-NCs on the electrode. However, this assertion can be verified empirically by performing scanning electrochemical microscopy, SEM or EIS on the modified electrode. To address why you have difficulty or in your word "trouble" to reproduce the data, I think you should find a way to ensure that the electrodeposited Pd-NCs are not leached out in the medium you perform the electrochemical measurement. If leaching takes place certainly, your electrochemical results will undoubtedly be dissimilar or irreproducible. Please note that as you perform the measurement using the unmodified electrode, you may observe that the shape of the CVs is almost exactly the same. This is indicative of the possible leaching or washing away of the Pd-NCs from the surface of the modified electrode.

Finally, the question at this point in time is not about interpreting the CVs but, depends on making sure that you obtain highly reproducible result, only then the interpretation of the accurate data comes into play.

Best of luck

Abubakar A'Salam

Hi, some comments from my side:

- Check that you have really deposited Pd (via high-resolution scanning electron microscopy).

- Higher currents can result from a larger surface area (due to crystals)

- Have you used the silver reference of your Metrohm electrode? Instead, try an external real Ag/AgCl or other electrode. Pure silver electrodes can change depending on the chloride and/or adsorption of other species.

Best regards,

Andreas

I agree with both previous answers. As Andreas Heyn points out, move towards a reliable reference electrode, this will make it easier to analyse the CVs and should rule out a secondary reaction occurring.

Can you show a set of scans to demonstrate how the response evolves?

Jules