I have read many papers on working of electrochemical sensing of materials. Somewhere researchers plot i(current) vs. v^1/2(square root of scan rate) and somewhere i(current) vs v(scan rate) to get a linear graph, so they can know whether a reaction is absorption or diffusion based.

My question is on what parameters we plot i vs. v or v^1/2 in a graph because there could be a possibility of having linear graphs with both v or v^1/2.

Thanks