Adsorption of Benzotriazole on Copper Electrode Surfaces in Citric Acid Media

The corrosion inhibition of copper in 0.001 M to 1.0 M citric acid (C6H8O7) solution by benzotriazole (BTA, C6H5N3) has. been investigated using gravimetric measurements. BTA was tested in concentrations from 1 x 10(6) M to 1 x 10(-1) M at temperatures of 298, 308, 318, and 328 K. The inhibitor mechanism is discussed in terms of applicability of Langmuir, Frumkin, Hill-de Boer, Parsons, Damaskin-Parsons, Kastening-Holleck, Flory-Huggins, Dhar-Flory-Huggins, and Bockris-Swinkels isotherms. The best fit was obtained using the Frumkin isotherm model. A structural parameter, the projected molecular area of BTA, was calculated to elucidate inhibitor orientation in the adsorption process.