Fabrication of electrically conducting graphitic carbon nitride film on glassy carbon electrode with the aid of amine groups for the determination of an organic pollutant

Abstract

Abstract Fabrication of conducting graphitic carbon nitride (GCN) on glassy carbon (GC) electrode and its electrocatalytic activity towards the reduction of nitrobenzene (NB) were presented in this paper. The GCNs were prepared from melamine and thiourea by pyrolysis and characterized by FT-IR, XRD, SEM and XPS. Due to its poor electronic conductivity, GCN was very rarely used for electrocatalytic applications. However, the electrical impedance spectroscopy results reveal that the charge transfer resistance of GCNs modified GC electrodes prepared from melamine (M) and thiourea (TU) precursors was lower than that of bare GC electrode under optimized experimental conditions. Among the two GCNs, GCN-TU modified electrode showed lesser charge transfer resistance than GCN-M modified electrode. This was attributed to the formation of stacked sheet like structure of GCN-TU in contrast to bulk like structure with few sheets of GCN-M on GC surface. Further, the electrocatalytic activity of the GCNs modified electrode towards the reduction of NB was studied. Owing to its higher electroactive surface area and conductivity, GCN-TU modified electrode exhibited higher current than GCN-M and GC electrodes. The differential voltammetric current of NB linearly increases in the concentration range from 10 μM to 1 mM with the correlation coefficient of 0.9983 and the LOD was found to be 1.3 μM (S/N = 3). Finally, the practical application was established by determining NB in lake water samples.