2D-Graphitic Carbon Nitride Nanosheet/Metal Nanocomposites for Electrochemical Sensors of Hydroquinone in Real Sample Analysis

In the present work, we have investigated a low-costfabricationmethod in preparing two-dimensional (2D) graphitic carbon nitride(g-C3N4) with nanosheet/metal nanocompositesby a rapid calcination process. The synthesized metal/g-C3N4 nanosheet was analyzed further by using UV-visible,Fourier transform-infrared spectroscopy (FTIR), powder X-ray diffraction(XRD), and energy-dispersive X-ray spectroscopy (EDAX) with elementalanalysis mapping. Through field emission scanning electron microscopy(FE-SEM) and transmission electron microscopy (TEM), the metal/g-C3N4 nanosheet was observed to have a porous nanostructure.X-ray diffraction patterns of the 2D-GCN nanostructure were confirmedto be of fine crystalline size. X-ray photoelectron spectroscopy providedqualitative and quantitative data about the structure of C3N4. An electrochemical performance was carried out byusing cyclic and differential pulsed voltammetry techniques. The metal/g-C3N4 nanosheet/nanocomposite was fabricated on theglassy carbon electrode (GCE) for electrochemical determination ofhydroquinone (HQ). The electrocatalytic mechanism of HQ was scrutinized,which proved fast electron and ion transfer phenomena. The as-preparedAg/g-C3N4/GCE exposed greater performance witha low limit of detection (LOD) of 5.8 mu M in a wide linear rangefrom 0.99 to 999.96 mu M, which shows better repeatability, reproducibility,stability and an outstanding selectivity. The Ag/g-C3N4/GCE-fabricated electrode exhibited good sensitivity at 0.067 mu A Mm(-1) cm(-2). The proposedsensor additionally verified its practical feasibility in real-timemonitoring on river and tap water samples with a satisfactory recovery.

Automated summary

In this study, a low-cost fabrication method was used to synthesize metal/2D graphitic carbon nitride (g-C3N4) nanosheet/metal nanocomposites. The synthesized nanosheet was characterized by various techniques, revealing its porous nanostructure and fine crystalline size. It exhibited excellent electrochemical performance, with low detection limit and high sensitivity, making it suitable for real-time monitoring of water samples.