Preparation of nano-copper oxide modified glassy carbon electrode by a novel film plating/potential cycling method and its characterization

Abstract An electrochemical sensor for H 2 O 2 determination was prepared by electrodepositing nano-copper oxide on glassy carbon electrode by a novel film plating/potential cycling method. A copper film was first cathodically deposited on the surface of GC in CuCl 2 solution at −0.4 V, then a nano-copper oxide film was in situ deposited on the surface of GC by potential cycling at −0.5 to 0.3 V in 0.1 mol L −1 NaOH solution. The mechanism of nano-copper oxide film formation and factors affecting its electrochemical activity were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The chronoamperometric detection of H 2 O 2 was carried out at 0.2 V in 0.01 mol L −1 NaOH solution and the linear range was 2–270 nmol L −1 with a detection limit of 0.2 nmol L −1 ( S / N  = 3), which is lower than that reported in related literatures. The response time to achieve the steady-state current was 2 O 2 in real water, which exhibited high analytical sensitivity and reproducibility.