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The tunability of porous covalent triazine frameworks (CTFs) can mitigate poor photostability and rapid hole-electron recombination. Herein, an excellent improvement of visible light–driven photocatalytic pollutant degradation was achieved using a hybrid semiconductor of covalent triazine framework-zinc ferrite spinel catalysts (CTF-ZnFe2O4). The as-prepared CTF-ZnFe2O4 composites were fabricated using a facile one-pot ionothermal method. The hybrid photocatalysts were identified using X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM–EDX), X-ray photoelectron spectrometer (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), and UV–visible diffuse reflection spectroscopy (UV–vis DRS) characterizations. The analysis reveals that hybridization successfully ensued and altered the crystallinity structure, morphology, surface area, and bandgap energy of hybrid material. It was found that CTF-ZnFe2O4 90:10 is very effective for the degradation of MB in a UV–vis light photocatalytic process with the efficiency of 95.4% and kobs of 0.421 min−1 for degradation of 50 mg/L MB with 0.5 g/L dosages for 120 min. Additionally, the scavenger study, effect of additional oxidants, and stability were performed for the practical application of a hybrid photocatalyst. CTF-ZnFe2O4 90:10 shows outstanding pollutant degradation in sunlight irradiation and high stability with only a 5.2% reduction after a five-times sequential recycling process. Moreover, the photocatalytic mechanism of as-prepared CTF-ZnFe2O4 was mainly influenced by O 2 ∙ - radical compared to h + vb and ∙ OH radicals. Overall, The as-prepared CTF-ZnFe2O4 shows significant potential to be utilized for photocatalytic wastewater treatment. [ABSTRACT FROM AUTHOR]

Herein, a series of covalent triazine framework/bismuth vanadate (CTF/BiVO4) heterojunction catalysts were prepared using the hydrothermal method. The mechanism of the CTF/BiVO4 heterojunction photocatalyst in the system was examined to provide a theoretical basis for constructing a high-efficiency photocatalysis composite system for removing organic pollutants from water. Compared with CTF and BiVO4 catalysts alone, composite materials have been shown to have significantly higher degradation efficiencies against organic pollutants in water. Moreover, the degradation effect was found to be optimal when the mass ratio of CTF to BiVO4 was 1:1 (1-CTF/BiVO4). On the basis of physicochemical characterization results, it was concluded that the effective construction of CTF/BiVO4 composite photocatalyst material systems and the formation of type II heterojunction structures between CTF and BiVO4 effectively promote the separation of photogenerated carriers and increase the interface charge transfer efficiency. [ABSTRACT FROM AUTHOR]

Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media. [ABSTRACT FROM AUTHOR]

It is found that a covalent triazine framework (CTF–1) (that was prepared from 1,4–dicyanobenzene) exhibits oxidase–like activity toward the oxidation of luminol with dissolved oxygen in alkaline condition to produce intense blue chemiluminescence (CL). The reaction follows Michaelis–Menten kinetics and shows strong specificity for luminol. Reactive oxygen species including 1O2, •OH and O2•− are testified to be involved in the reaction and responsible for the CL. The reaction was applied to the determination of the radical–scavenging activity of antioxidants, with rutin, kaempferol and ferulic acid serving as model scavengers. A sensitive CL method was developed for the determination of rutin based on its inhibitory effect on the reaction. The CL system gave a linear response to the concentration of rutin in the range of 0.03–0.25 μmol·L−1 with a limit of detection of 0.015 μmol·L−1. The practicability of the method was demonstrated by successful determination of rutin in tablets and in Flos Sophorae Immaturus. [ABSTRACT FROM AUTHOR]