Corrosion inhibition effect of sodium phytate on brass in NaOH media. Potential-resolved formation of soluble corrosion products

Corrosion inhibition of brass by phytate in alkaline media was evaluated by cyclic voltammetry, UV-vis spectra, derivative cyclic voltabsorptometry (DCVA) and scanning electron microscopy. A thin-layer electrochemical cell was fabricated with an appropriate light-path-length. A high corrosion inhibition efficiency of phytate on brass was achieved in 0.1 mol dm(-3) NaOH. Soluble ions such as Zn(OH)(4)(2-), Cu(I) intermediate ion, Cu(OH)(4)(2-) and another Cu(II)-O complex, were monitored in situ under potentiostatic and potentiodynamic conditions. The DCVA curves at given wavelengths show five positive and three negative peaks corresponding to the potential-resolved formation and reduction of various soluble corrosion products. (C) 2013 Elsevier Ltd. All rights reserved.