Electro-catalytic effect of Al2O3 supported onto activated carbon in oxidizing phenol at graphite electrode

In this work, the electro-catalytic oxidation of phenol was studied using the aluminum oxide supported onto activated carbon (Al2O3/AC). The later was successfully prepared by impregnating aluminum particles in the activated carbon (AC) using heat treatment. Al2O3/AC was characterized by X-ray diffraction (XRD) and infrared spectroscopy (IR). The electro-catalytic performance of the Al2O3/AC for phenol oxidation was studied using cyclic voltammetry (CV), chronoamperometry, linear sweep voltammetry polarization, electrochemical impedance spectroscopy and differential pulse voltammetry (DPV) in 0.1 mol L-1 Na2SO4. It has been shown that the proposed catalyst exhibits remarkably an electro-catalytic performance toward phenol oxidation. Moreover, the oxidation peak currents are linearly dependent on the concentration of phenol in the wide ranges from 1.0 x 10(-3) mol L-1 to 1.0 x 10(-4) mol L-1 and 8.0 x 10(-5) mol L-1 to 1.0 x 10(-6) mol L-1 with a detection limit of 1.51 x 10(-7) mol L-1 (signal (S) to noise (N) ratio, S/N = 3) and response time of 3 min. The possible interferences were evaluated in 1.0 x 10-5 mol L-1 of phenol. The proposed catalyst also indicated suitable repeatability and stability. Moreover, the proposed Al2O3/AC-CPE has been successfully applied for the phenol analysis in natural waters and olive oil samples with good recoveries. (C) 2017 Elsevier Ltd. All rights reserved.