Low-Cost Graphene-Based Composite Electrodes for Electrochemical Oxidation of Phenolic Dyes
Marija Ječmenica Dučić,
Aleksandar Krstić,
Nikola Zdolšek,
Danka Aćimović,
Branislava Savić,
Tanja Brdarić,
Dragana Vasić Anićijević
Affiliations
Marija Ječmenica Dučić
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Aleksandar Krstić
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Nikola Zdolšek
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Danka Aćimović
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Branislava Savić
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Tanja Brdarić
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Dragana Vasić Anićijević
Vinča Institute of Nuclear Sciences-National Institute of the Republic of Serbia, Department of Physical Chemistry, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia
Electrochemical removal of organic pollutants represents an attractive methodology in water depollution. The key challenges for researchers comprise finding simple, affordable electrode materials with satisfactory efficiency in all ranges of pollutant concentration. Electrochemical oxidation of a mixture of phenol-based dyes: bromocresol green (BCG), cresol red (CR), and thymol blue (TB), in sulphate medium, at total concentration not exceeding 15 ppm, has been performed using simply prepared, low-cost composite electrodes, based on graphene nanoplatelets (GNP) and metallic oxides (TiO2 and SnO2) loaded on stainless steel substrate: GNP@SS, SnO2/GNP@SS, and TiO2/GNP@SS. Electrodes were characterised by XRD, FTIR, and electrochemical techniques. The degradation kinetics of initial dyes was tracked with UPLC and GC-MS chromatography for 6 h, at a current density of 10 mA/cm2. GC-MS analysis of the degradation products revealed oxidised aromatic compounds as the main products, while TOC analysis confirmed a total mineralisation extent in the range of 30–35%. The proposed degradation mechanism involves the attack of OH-radical, as the main oxidising agent, to the hydroxyl oxygens of dye phenolic rings. Obtained results provide useful information for the further development of affordable laboratory-scale and industrial systems for the complete removal of phenol-based compounds.
