In DPV, the peak current equals:

(δi)max = nFAC * sqrt( D / (π*Δτ) * (1-σ)/(1+σ)

Where Δτ is the pulse duration and σ = exp(nF/RT * ΔE/2) where ΔE is the pulse height.

Source: Bard & Faulkner - Electrochemical Methods

As  dear René Becker said, in DPV, equetion there are no scan rate parameter, but, the Randles–Sevcik equation( for CV) , explains the relationship between of scan rate and the peak current as follows:

ip = 268, 600 n 3/2 AD1/2 C v1/2   

ν = scan rate in V/s

Good Luck

From the attached paper, peak current decreases as function of scan rate for a surface confined redox process. 

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