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-cost fabrication method in preparing two-dimensional (2D) graphitic carbon nitride (g-C3N4) with nanosheet/metal nanocomposites by 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 elemental analysis 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 confirmed to be of fine crystalline size. X-ray photoelectron spectroscopy provided qualitative and quantitative data about the structure of C3N4. An electrochemical performance was carried out by using cyclic and differential pulsed voltammetry techniques. The metal/g-C3N4 nanosheet/nanocomposite was fabricated on the glassy carbon electrode (GCE) for electrochemical determination of hydroquinone (HQ). The electrocatalytic mechanism of HQ was scrutinized, which proved fast electron and ion transfer phenomena. The as-prepared Ag/g-C3N4/GCE exposed greater performance with a low limit of detection (LOD) of 5.8 μM in a wide linear range from 0.99 to 999.96 μM, which shows better repeatability, reproducibility, stability and an outstanding selectivity. The Ag/g-C3N4/GCE-fabricated electrode exhibited good sensitivity at 0.067 μA Mm–1 cm–2. The proposed sensor additionally verified its practical feasibility in real-time monitoring on river and tap water samples with a satisfactory recovery.