In this work, graphitic carbon nitride (g-C3N4)/titanium dioxide (TiO2) nanoparticles with heterostructures were synthesized in situ from a mixture of melamine and peroxo-titanium complexes in a calcination process. The TiO2 nanoparticles are well-dispersed on the g-C3N4 nanosheets. The prepared TiO2/g-C3N4 composites have a heterostructure and excellent photocatalytic activity for decomposing methylene blue (MB) under visible light irradiation. The as-obtained g-C3N4 embroiled with TiO2 has a much larger surface area than its components (66.7 and 6.6 m2·g−1 for TiO2 and g-C3N4 against 95.5–143.8 m2·g−1 for the composite, respectively). It enhances the separation of photo-generated charge carriers. The TiO2/g-C3N4 photocatalytic degradation of MB was investigated in aqueous heterogeneous suspensions. The experimental kinetic data for the photocatalytic process follow the pseudo-first-order kinetic model. Furthermore, TiO2/g-C3N4 retains high photocatalytic activity after four reaction cycles. In addition to prompt removal of the color, the TiO2/g-C3N4 photocatalyst can oxidize MB almost completely to final oxidation products. The pathway of MB decomposition was also addressed. Additionally, the TiO2/g-C3N4 photocatalytic system was employed to eliminate other typical organic pigments, such as malachite green, methyl blue, and methyl red. The TiO2/g-C3N4 material, with remarkable dye degradability, is a promising catalyst in industrial textile treatment and can find applications in light-harvesting systems.
From the dichloromethane extract of the whole plant of P. angulata growing in Vietnam, three withanolides including physagulin L (1), physagulin M (2), and withaminimin (3) were isolated by using various chromatography methods. Their chemical structures were determined by detailed analysis of 1D and 2D-NMR data and comparison with reported data. All isolated compounds were tested for their inhibitory activities against NO production in LPS-stimulated RAW 264.7 macrophages. The results showed that compound 3 had a weak anti-inflammatory activity against NO production in RAW 264.7 macrophages with IC50 value of 69.6±4.5 μM.
A facial differential pulse voltammetric procedure using a glassy carbon electrode modified with zeolite imidazolate framework-67/graphitic carbon nitride (ZIF-67/g-C3N4) for the diclofenac (DCF) determination is demonstrated. ZIF-67/g-C3N4 with different mass ratios of the components was synthesized in a self-assembly process. The obtained materials were characterized by using X-ray diffraction, scanning electron microscopy (SEM), EDX-mapping, and nitrogen adsorption/desorption isotherms. The peak current varies linearly with the DCF concentration in the range of 0.2–2.2 μmol·L−1 and has a detection limit of 0.071 μmol·L−1. The modified electrode exhibits acceptable repeatability, reproducibility, and selectivity towards DCF. The proposed electrode allows determining DCF in human urine without pretreatment, and the results are comparable with those determined with HPLC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.