What primarily determines the shape of the cyclic voltammogram peaks?

The shape of the cyclic voltammogram peaks is primarily influenced by the scan rate and the reversibility of the electrochemical reaction.

When conducting a cyclic voltammetry experiment, the scan rate refers to how fast the potential is varied. A higher scan rate means that the potential is changing more rapidly, which can enhance peak height due to the increased current response from the electrochemical reaction. However, this can also lead to broader peaks because there is less time for the system to equilibrate, resulting in diffusion limitations.

The reversibility of the reaction plays a crucial role as well. For a fully reversible process, the peaks in the cyclic voltammogram are well-defined and symmetrical. In contrast, if a reaction is irreversible or quasi-reversible, the peak shapes can become distorted, displaying features such as asymmetry in peak height and width, which can complicate the interpretation of the electrochemical behavior.

In summary, the interplay between the scan rate and the reaction's reversibility directly impacts the characteristics of the cyclic voltammogram peaks, making this option the most relevant factor in determining their shape. Other factors, such as concentration, electrode material, and temperature, can certainly influence the overall behavior of the system, but they do not primarily dictate the