I performed CV of Cu-MOF in a buffer solution of pH 8, and we did not find any peak corresponding to Cu2+ to Cu+. What is the reason behind this? Please give your valuable suggestions.
Dear Ajit Singh You may check the stability of MOF at given conditions, buffer composition and ionic strength that affects redox behavior, also the potential window may the factor. In our case, the peaks for Cu+2/Cu+1 redox couple is around 0.1 to 0.5 V vs Ag/AgCl.
The absence of a cathodic peak for Cu2+ to Cu+ in your cyclic voltammetry (CV) curve could be due to several factors. Here are some possibilities and troubleshooting tips:
1. Slow reduction kinetics:
- The reduction of Cu2+ to Cu+ at pH 8 might be kinetically slow, meaning the electron transfer process is sluggish. This could lead to a very small or broad cathodic peak that's difficult to observe.
Solution:
- Try scanning at slower scan rates. Slower scan rates allow more time for the electron transfer to occur, potentially resulting in a more pronounced cathodic peak.
- Consider using a supporting electrolyte with known complexation abilities for Cu2+. This can help with the reduction process. For instance, citrate or chloride ions can form complexes with Cu2+ that might be easier to reduce.
2. Insufficient potential window:
- The chosen potential window in your CV experiment might not be reaching the reduction potential for Cu2+ to Cu+ at pH 8.
Solution:
- Based on literature references, determine the expected reduction potential for Cu2+ to Cu+ at pH 8.
- Adjust your cathodic scan limit in the negative direction to encompass this reduction potential. Be mindful of the solvent window to avoid unwanted solvent decomposition.
3. Electrode limitations:
- The working electrode material might not be suitable for the reduction of Cu2
4. Experimental issues:
- Issues like high solution resistance, poor electrical contact, or insufficient Cu2+ concentration can also affect the CV response.
Solution:
- Double-check your cell setup for proper connections and cleanliness.
- Ensure your electrolyte solution has a low enough resistance (typically less than 100 ohms).
- Use an appropriate Cu2+ concentration in your solution. A higher concentration might lead to a more visible peak, but be mindful of solubility limitations.
Hope it will help!
Regards
Monika Antil
Hello Ajit Singh ,
Please check it in different electrolytic solutions e.g., HCl, NaOH, etc. Also, check it at different pH of PBS solution. pH and electrolytic solutions are the two main factors that determine the response.
- Badges
- Science topic
- Similar topics
- Filing