title: The application of exfoliated graphite electrode in the electrochemical degradation of p-nitrophenol in water.
abstract: We report the application of exfoliated graphite (EG) as an electrode material in the electrochemical degradation of p-nitrophenol in water. Bulk electrolysis (degradation) of p-nitrophenol was carried out at a potential of 2.0 V (vs. Ag/AgCl) in the presence of 0.1 M Na2SO4 supporting electrolyte, while UV-Vis spectrophotometry was used to monitor the degradation efficiency. An initial p-nitrophenol load concentration of 0.2 mM for 3 h electrolysis time was studied under the optimized conditions of pH 7, and 10 mAcm(-2) current density. The electro-degradation reaction displayed a pseudo-first-order kinetic behavior with a rate constant (k(r)) of 11×10(-3) min(-1). The removal efficiency was found to be 91.5%. Chromatography coupled with time of flight mass spectrometry revealed p-benzoquinone as a major intermediate product. These results demonstrate the potential and viability of electrochemical technology as an alternative approach to water treatment using a low cost graphite electrode.
authors.affiliation: a Department of Applied Chemistry , University of Johannesburg , Doornfontein , South Africa.
authors.forename: Bulelwa
authors.initials: B
authors.lastname: Ntsendwana
authors.affiliation: a Department of Applied Chemistry , University of Johannesburg , Doornfontein , South Africa.
authors.forename: Moses G
authors.initials: MG
authors.lastname: Peleyeju
authors.affiliation: a Department of Applied Chemistry , University of Johannesburg , Doornfontein , South Africa.|b Center for Nanomaterials Science Research, University of Johannesburg , Doornfontein , South Africa.
authors.forename: Omotayo A
authors.initials: OA
authors.lastname: Arotiba
mesh_terms: D004566:Electrodes; D004572:Electrolysis; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D009596:Nitrophenols / Q000737:chemistry*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D009596:Nitrophenols; D014874:Water Pollutants, Chemical; D006108:Graphite; C024836:4-nitrophenol
keywords: Degradation; electrochemical oxidation; exfoliated graphite electrode; p-nitrophenol; removal efficiency; water