Functionalized Graphitic Carbon Nitride Decorated with Palladium: an Efficient Heterogeneous Catalyst for Hydrogenation Reactions Using KHCO2 as a Mild and Noncorrosive Source of Hydrogen

Polydopamine Coating of Graphitic Carbon Nitride, g-C3N4, Improves Biomedical Application

Graphitic carbon nitride (g-C3N4) is an intriguing nanomaterial that exhibits photoconductive fluorescence properties under UV-visible light. Dopamine (DA) coating of g-C3N4 prepared from melamine was accomplished via self-polymerization of DA as polydopamine (PDA). The g-C3N4 was coated with PDA 1, 3, and 5 times repeatedly as (PDA@g-C3N4) in tris buffer at pH 8.5. As the number of PDA coatings was increased on g-C3N4, the peak intensity at 1512 cm-1 for N-H bending increased. In addition, the increased weight loss values of PDA@g-C3N4 structures at 600 °C from TGA thermograms confirmed that the coating was accomplished. The band gap of g-C3N4, 2.72 eV, was reduced to 0.87 eV after five coatings with PDA. A pristine g-C3N4 was found to have an isoelectric point (IEP) of 4.0, whereas the isoelectric points of 1PDA@g-C3N4 and 3PDA@g-C3N4 are close to each other at 3.94 and 3.91, respectively. On the other hand, the IEP of 5PDA@g-C3N4 was determined at pH 5.75 assuming complete coating with g-C3N4. The biocompatibility of g-C3N4 and PDA@g-C3N4 against L929 fibroblast cell lines revealed that all PDA@g-C3N4 coatings were found to be biocompatible up to a 1000 mg/mL concentration, establishing that PDA coatings did not adversely affect the biocompatibility of the composite materials. In addition, PDA@g-C3N4 was screened for antioxidant potential via total phenol content (TPC) and total flavonoid content assays and it was found that PDA@g-C3N4 has recognizable TPC values and increased linearly with an increased number of PDA coatings. Furthermore, blood compatibility of pristine g-C3N4 is enhanced considerably upon PDA coating, affirmed by hemolysis and the blood clotting index%. Additionally, α-glucosidase inhibitory properties of PDA@g-C3N4 structures revealed that 67.6 + 9.8% of this enzyme was evenly inhibited by 3PDA@g-C3N4 structure.

EL-Sanafery S. Graphitic Carbon Nitride/MOFs Hybrid Composite as Highly Selective and Sensitive Electrodes for Calcium Ion Detection

The metal-organic framework (MOF) is a class of materials that exhibits a notable capacity for electron transfer. This unique framework design offers potential applications in various fields, including catalysis, gas storage, and sensing. Herein, we focused on a specific type of MOF called Ti-MOF. To enhance its properties and functionality, the composite material was prepared by incorporating graphitic carbon nitride (g-C3N4) into the Ti-MOF structure. This composite, known as g-C3N4@Ti-MOF, was selected as the active material for ion detection, specifically targeting calcium ions (Ca2+). To gain a comprehensive understanding of the structural and chemical properties of the g-C3N4@Ti-MOF composite, several analytical techniques were employed to characterize the prepared g-C3N4@Ti-MOF composite, including X-ray diffraction (XRD), SEM-EDX, and FT-IR. For comparison, different pastes were prepared by mixing Ti-MOF or g-C3N4@Ti-MOF, graphite, and o-NPOE as a plasticizer. The divalent Nernstian responses of the two best electrodes, I and II, were 28.15 ± 0.47 and 29.80 ± 0.66 mV decade-1, respectively, with concentration ranges of 1 µM-1 mM and 0.1 µM-1 mM with a content 1.0 mg Ti-MOF: 250 mg graphite: 0.1 mL o-NPOE and 0.5 mg g-C3N4@Ti-MOF: 250 mg graphite: 0.1 mL o-NPOE, respectively. The electrodes showed high sensitivity and selectivity for Ca2+ ions over different species. The suggested electrodes have been successfully employed for Ca2+ ion measurement in various real samples with excellent precision (RSD = 0.74-1.30%) and accuracy (recovery = 98.5-100.2%), and they exhibited good agreement with the HPLC.

C-O band structure modified broad spectral response carbon nitride with enhanced electron density in photocatalytic peroxymonosulfate activation for bisphenol pollutants removal

Here, a simple one-step calcination method uses glycolic acid (GA) and urea to synthesize C-O band structure modified carbon nitride with broad spectral response, which is used to construct a peroxymonosulfate/visible light (PMS/vis) system. The solid-state ¹³C NMR proved that C-O band structure was successfully introduced into the carbon nitride. Density functional theory (DFT) calculation show that the introduction of C-O band structure shortens the band gap of 0.05 g GA modified CN (0.05 GA-CN). Besides, Ultraviolet photoelectron spectroscopy (UPS) further illustrate that the 0.05 GA-CN has a higher charge density and promotes the degradation of pollutants. In PMS/vis system, 0.05 GA-CN can completely degrade bisphenol A (BPA) within 36 min. In addition, 0.05 GA-CN can also degrade bisphenol E (BPE) and bisphenol F (BPF). The cyclic voltammetry (CV) curve show that the introduction of C-O band structure enhances the activation ability of PMS. At the same time, 0.05 GA-CN/PMS has enhanced the activity of degrading BPA under blue light (450-462 nm), green light (510-520 nm) and red light (610-625 nm). This research provides a new method to synthesize carbon nitride with enhanced electron density for degradation of bisphenol pollutants in PMS/vis system.