Graphitic carbon nitride (g-C₃N₄)/graphite nanocomposite as an extraordinarily sensitive sensor for sub-micromolar detection of oxalic acid in biological samples

Abstract

Nanosized graphitic carbon nitride (nano-g-C 3 N 4 ) was synthesized using the thermal polymerization of melamine and utilized as a novel electrocatalyst for electrooxidation of oxalic acid (OA). The nano-g-C 3 N 4 was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The electrocatalytic performance of the g-C 3 N 4 -modified carbon paste electrode (g-C 3 N 4 /CPE) was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The modified electrode showed excellent electrocatalytic activity towards the oxidation of OA. The effects of electrode composition, pH and scan rate on the electrooxidation response of OA were studied. Under optimized conditions, the differential pulse voltammetric response of the electrode was linearly related to OA concentrations between 1 and 1000 mM, with a limit of detection (LOD) of 7.5 Â 10 À7 M. The electrode exhibited very high sensitivity of 1945 mA mM À1 cm À2 for OA assay. The developed method was successfully applied for the determination of OA in urine samples with satisfactory results. Experimental Apparatus and chemicalsThe surface morphology of the prepared g-C 3 N 4 was examined by means of FE-SEM (TESCAN MIRA, Czech). The crystalline

Synergistically enhanced solar light‐driven degradation of hazardous food colorants by ultrasonically derived MgFe2O4/S‐doped g‐C3N4 nanocomposite: A Z‐scheme system‐based heterojunction approach

“…[ 84 ] The strong peak positioned at 2θ = 27.4° is attributed to the interplanar stacking of the conjugated aromatic framework, whereas the peak at 2θ = 13.1° relates to in‐plane repeating structural units of tri‐s‐triazine. [ 85,86 ] The XRD pattern of SCNNS also displayed the similar peaks at approximately same 2θ values but with a quite decrement in their intensities. Additionally, the intensification in broadness of the peaks was also noticed.…”

Utilizing ferrocene for doping iron into graphitic carbon nitride (FeIII/g-C3N4): an internal dual photocatalyst for tandem oxidation/cyclization of toluene to benzimidazoles under visible light conditions

“…43 The diameter of the semicircles is assigned to the value of the load transfer resistance for g-C 3 N 4 and Fe III /g-C 3 N 4 in the attributed electrodes. In fact, a smaller diameter of the EIS diagram demonstrates a much easier charge transfer through the electrode/electrolyte interface 44 and the diameter of the EIS diagram of Fe III /g-C 3 N 4 is notably smaller than that of g-C 3 N 4 , proposing that the iron ion (Fe 3+ ) in nanocomposite Fe III /g-C 3 N 4 can capture the photo-produced electrons; so for the useful separation of light-induced electric circuits, there is more effective interfacial charge movement between the electrolyte and the electrode, which increases the conductivity of Fe III /g-C 3 N 4 . 45 The semicircle portion in the EIS graphs at high frequencies corresponded to electron transfer resistance ( R et ).…”

“…43 The diameter of the semicircles is assigned to the value of the load transfer resistance for g-C 3 N 4 and Fe III /g-C 3 N 4 in the attributed electrodes. In fact, a smaller diameter of the EIS diagram demonstrates a much easier charge transfer through the electrode/electrolyte interface 44 and the diameter of the EIS diagram of Fe III /g-C 3 N 4 is notably smaller than that of…”

Synthesis of neodymium ferrite incorporated graphitic carbonitride (NdFe2O4@g-C3N4) and its application in the photodegradation of ciprofloxacin and ampicillin in a water system

“…1234 cm −1 are characteristic of aromatic C-N stretch, which may be associated with secondary and tertiary amine fragments, respectively. 36,37 The O-Fe-O stretch was seen at 1140 cm −1 in both NdFe 2 O 4 and NdFe 2 O 4 @g-C 3 N 4 . The 720 and 622 cm −1 signals were attributed to Nd-O and Fe-O vibrations in NdFe 2 O 4 and NdFe 2 O 4 @g-C 3 N 4 , respectively.…”