Electrocatalytic effect of NiO supported onto activated carbon in oxidizing phenol at graphite electrode: Application in tap water and olive oil samples

The experimental conditions were optimized by varying chemical and electrochemical parameters, which involve the oxidation of phenol. The electrode NiO/AC-CPE exhibits a good linear range from 1.0 × 10−6 mol L−1 to 8.0 × 10−5 mol L−1 and 1.0 × 10−4 mol L−1 to 1.0 × 10−3 mol L−1 with a limit of detection of 7.09 × 10-7 mol L-1 (signal (S) to noise (N) ratio, S/N = 3). This modified electrode NiO/AC-CPE offers a considerable improvement in voltammetric sensitivity toward phenol determination, compared to the unmodified electrode (CPE). The selectivity of the NiO/AC-CPE in detecting phenol was investigated for a number of ions (Cu2+, Cd+2, Ag+, Pb2+, Zn2+, Fe3+, Ni2+, Al3+, Mg2+, Ag2+ and Cr3+) and biomolecules (4-nitrophenol, dopamine, 2-nitrophenol, paracetamol, hydroquinone, catechol, resorcinol, 4-aminophenol and 3-aminophenol). The proposed method was successfully applied to phenol determination in tap water and olive oil.