Naproxen electrooxidation using carbon paper electrodes modified with reduced graphene oxide and platinum nanoparticles

Abstract

This research study investigates the electrooxidation of naproxen (NPX), an anti-inflammatory pharmaceutical, on modified carbon paper (CP) electrodes. Electrochemical modification of CP electrodes was accomplished with Pt or reduced graphene oxide (RGO)-Pt coatings, resulting in the production of electroactive electrodes. RGO coatings synthesized by cyclic voltammetry (CV) for 10 scans provided the optimal coverage for the CP electrode surface. The deposition of Pt nanoparticles (Pt NPs) on the electrodes (CP or CP-RGO) by CV produced a good electrode surface coverage with 20 synthesis scans. The voltammetric analysis of the electrodes in 230 mg/L NPX solution showed oxidation peaks around 1.0 to 1.2 V. Moreover, the inclusion of RGO in the coating led to an increase in the current density of these oxidation peaks and a decrease of the electrode electron transfer resistance as measured by electrochemical impedance spectroscopy.The electrolysis of NPX in different electrolytes (Na2SO4 and Na2SO4/NaCl) was conducted at 1.4 V, and the removal of NPX was analyzed using high-performance liquid chromatography. The CP-RGO-Pt electrode in Na2SO4/NaCl media showed the fastest NPX degradation kinetics, resulting in a 90 % degradation in only 90 min with low charge consumption (0.07 A·h·L-1). The smaller size of Pt NPs deposited on CP-RGO, as observed by field emission scanning electron microscopy and transmission electron microscopy, contributed to the higher electrochemical response in CV and a faster kinetic degradation of NPX.