Graphitic carbon nitride as electrode sensing material for tetrabromobisphenol-A determination

Graphitic carbon nitride (g-C3N4), a green and cost-efficient semiconductor, is considered to be inconveniently applied in the field of electrochemistry due to its bad electrochemical activity. In this study, g-C3N4 was found to enhance the electrochemical response of tetrabromobisphenol-A (TBBPA) at glassy carbon electrode and then employed as a sensing material for further sensitive determination. The active mechanism, the discrepant electrochemical properties of the obtained g-C3N4 products and the pH-dependent interaction between g-C3N4 and TBBPA during the analysis process were investigated. For the investigation, g-C3N4 was synthesized at different temperatures and characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Moreover, the electrochemical properties of g-C3N4 after electrode modification were evaluated by electrochemical impedance spectroscopy (EIS) and chronocoulometry. Finally, TBBPA was quantified with the modified electrode in the range of 0.02 μM–1 μM with a detection limit of 5 nM. The presented properties of the modified electrode also enable its application in environmental samples detection.