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Antibiotics, such as tetracycline hydrochloride (TC), are persistent pollutants in the environment due to their difficult degradation properties. In this study, a MoS2/ZnO heterostructure nanocomposite was synthesized and evaluated for its photocatalytic performance in degrading TC under simulated sunlight irradiation. The degradation rate of TC in the MoS2/ZnO/PMS system reached 99.8% after 30 min, surpassing the rates observed in both ZnO and MoS2/ZnO systems. The presence of active species, including superoxide radicals (˙O2−), hydroxyl radicals (˙OH), sulfate (SO4˙−) and singlet oxygen (1O2), was confirmed through trapping experiments and electron paramagnetic resonance (ESR) analysis. The MoS2/ZnO heterostructure effectively suppressed the recombination of photogenerated charge carriers, leading to improved photocatalytic efficiency. The results demonstrate the potential of the MoS2/ZnO/PMS system as a low cost and efficient method for the removal of TC from water. This study contributes to the development of photocatalytic materials for the degradation of persistent organic pollutants in aqueous environments. [ABSTRACT FROM AUTHOR]

A novel AgI/Ag6Si2O7/PET Z-scheme heterojunction photocatalyst with strong redox capability was fabricated via a facile successive ionic layer adsorption and reaction (SILAR) method to degrade methyl orange (MO). Compared with Ag6Si2O7/PET and AgI/PET, the prepared AgI/Ag6Si2O7/PET heterojunction exhibits superior photocatalytic performance under visible light because of its strong interfacial coupling effects. The degradation rate constant of the optimal AgI/Ag6Si2O7/PET is up to 0.144 min−1, which is approximately 5.5 and 9.6 times greater than that of Ag6Si2O7/PET and AgI/PET, respectively. The radical capture experiments and ESR characterization demonstrate that h+ and ˙O2− are two major oxidative species responsible for the photocatalytic degradation of dyes. The PL, photocurrent and EIS analyses indicate that AgI/Ag6Si2O7/PET shows enhanced electron–hole pair separation efficiency. This phenomenon is related to three aspects, namely the high light-harvesting efficiency, greatly enhanced accessibility to the active site, and the formation of Z-scheme heterojunction structures that effectively improve the photoelectron–hole separation efficiency and the redox capacity of the photocatalyst. Our work, therefore, provides novel insights into the development of a heterojunction composite with boosted photocatalytic activity, excellent stability, and reusability for the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

In this article, amino-functionalized TiO2 (TiO2/KH550) was obtained via a mild reaction between 3-aminopropyltriethoxysilane and TiO2 with the aid of concentrated ammonia solution. 4-((4,6-Dichloro-1,3,5-triazine-2-yl)amino) sodium benzenesulfonate (SAT) was synthesized and characterized using 1H NMR and Fourier transform infrared spectroscopy (FT-IR). Self-dispersive and reactive TiO2 (TiO2/KH550/SAT) was prepared via a nucleophile substitution reaction between TiO2/KH550 and SAT. Finally, cotton fabric samples loaded with different amounts of TiO2/KH550/SAT were achieved via an exhaust dyeing method. The chemical structures, dispersions, and thermal performances of TiO2, TiO2/KH550, and TiO2/KH550/SAT were investigated using FT-IR, zeta potential measurements, and thermogravimetric analysis (TG). The crystalline phase, morphology, chemical composition, and optical absorption properties of the cotton fabrics were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Moreover, the anti-ultraviolet, self-cleaning, and washing fastness properties of the cotton fabrics were investigated. It was found that TiO2/KH550/SAT demonstrated excellent dispersion stability in aqueous solution, even after standing for a month. Cotton fabrics loaded with TiO2/KH550/SAT exhibited attractive anti-ultraviolet performance, highly efficient and durable self-cleaning activity, and appreciable washing fastness. A mechanism and possible reactions related to the preparation of the self-cleaning cotton fabrics loaded with TiO2/KH550/SAT were proposed. [ABSTRACT FROM AUTHOR]

Ag/Cu2O composites were prepared by the solvothermal and photo-reduction method. Then, Ag/Cu2O nanoparticle-immobilized cotton fabric with a 3D structure (Ag/Cu2O/CF) was successfully prepared by a relatively mild method, which was easy to be recycled and reused in the treatment of dye wastewater. Their composition, structure and morphology were carefully investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Their photocatalytic activities were evaluated by measuring the degradation of methyl orange (MO) under the irradiation of visible light. The results showed that the photocatalytic activities of Cu2O were influenced by the preparation time and Ag/Cu2O enhanced the photocatalytic performance of the composite compared to pure Cu2O. More importantly, the Ag/Cu2O/CF also exhibited superior photocatalytic performance and excellent reusability. The species capture experiment and the electron spin resonance (ESR) study showed that ˙OH, h+ and ˙O2− all took part in the MO degradation. Furthermore, the photocatalytic mechanism of Ag/Cu2O/CF has been proposed based on the experimental results. Therefore, the present work provides some insight into degradation of organic pollutants and the as-prepared composite has great potential for use in practical wastewater treatment. [ABSTRACT FROM AUTHOR]