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Photo-Fenton catalysis plays an important role in the degradation of organic pollutants in environmental sewage. In this paper, magnetic 0D/1D ZnFe2O4/ZnCO3 rod-like nanocomposites were fabricated by a simple one-pot solvothermal method, and then the produced magnetic 0D/1D ZnFe2O4/ZnO rod-like nanocomposites were formed via calcination at high temperature. The obtained 0D/1D ZnFe2O4/ZnCO3 has been fully investigated by x-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and vibrating sample magnetometry. Furthermore, the photocatalytic Fenton reaction of these two catalysts has been preliminarily evaluated for the degradation performance of organic dyes and antibiotics in wastewater. The results showed that, under visible-light irradiation, the ZnFe2O4/ZnCO3 composite material and its product, ZnFe2O4/ZnO, after high-temperature firing can achieve more than 90% photo-Fenton catalytic degradation of Rhodamine B (RhB) and tetracycline (TC) within 30 min, superior to that of ZnFe2O4, ZnCO3 , and ZnO monomers due to their larger specific surface area and more active sites. The magnetization saturation values of ZnFe2O4/ZnCO3-2 and ZnFe2O4/ZnO-2 were, respectively, around 34.20 emu/g and 15.00 emu/g, indicating that both have good magnetic recovery properties. After five cycles of experiments, the photo-Fenton catalytic properties of ZnFe2O4/ZnCO3-2 and ZnFe2O4/ZnO-2 on TC decreased slightly within 30 min, but the Fenton catalytic properties of RhB still maintained more than 98%, indicating that both have good magnetic recovery properties and strong structural stability. A possible photo-Fenton catalytic mechanism has been proposed based on free radical identification, electrochemical impedance spectra, photocurrent curves, and a Mott–Schottky diagram. This study provided two catalysts with excellent performance for the photo-Fenton catalytic degradation of pollutants in water. [ABSTRACT FROM AUTHOR]

WO3/C3N4 porous nanotubes (WO3/CNNT) with direct Z-scheme heterojunction have been developed through an effortless one-pot calcination self-assembly strategy. The synthesized WO3/CNNT heterojunction structure is different from conventional bulk g-C3N4 according to field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) spectra analysis, and has a better performance in photocatalytic degradation of pollutants. It is under a unique structure with an elevated interfacial area and high dispersion active sites, which can facilitate the degradation of some dye pollutants and antibiotics by heterojunctions, higher than that of bulk g-C3N4 and hollow g-C3N4 nanotubes. The photocatalytic experimental results indicated the optimum photocatalyst of the 2% WO3/CNNT sample with a BET surface area of 108.8 m2/g, which can rapidly remove Rhodamine B (RhB) and tetracycline (TC) up to 97.4% and 87.4%, respectively, under visible-light irradiation, which was about 3.4 and 83.8 times higher than that of individual CNNT and WO3 for RhB degradation. Additionally, the degradation of TC was around 1.1 and 14.3 times superior to that of individual CNNT and WO3. Furthermore, the porous WO3/CNNT heterojunction turned out to be stable and reusable after four cycles of experiments. Reactive free radical trapping experiments confirmed that holes (h+) and superoxide (·O2−) radicals are the most dominant species during photodegradation. Finally, a possible Z-scheme catalytic mechanism is proposed. In this work, some new insights are provided to design novel Z-scheme g-C3N4-based heterojunction photocatalysts with a porous nanotube structure and enhanced photocatalytic performance for high-efficiency degradation of dyes and antibiotics. [ABSTRACT FROM AUTHOR]

Byline: Hongdian Lu (Department of Chemical and Material Engineering Hefei University, Hefei Anhui 230022, P. R. China, lu_hd@ustc.edu); Quanzheng Zhang (Department of Chemical and Material Engineering Hefei University, Hefei Anhui [...]

Herein, a method is described for pyrolysis associated with in situ ultrasonic synthesis of flower-like p-n-type BiOCl/g-C3N4 assembled with nanosheets for enhancing the visible-light degradation of Rhodamine B (RhB). The formation process, structure, microscopic morphology, and photocatalytic activity of the samples were investigated in detail. In addition, the results of simulated visible light-driven photocatalytic experiments showed that, compared with pure g-C3N4, the BiOCl (20 wt %)/g-C3N4 composite photocatalyst exhibited better degradation ability with a maximum k value of 0.109 min−1, and the most significant total removal rate of RhB was up to 99 %, which is about ninefold in comparison with pure g-C3N4. Finally, the enhanced photocatalytic activities of the products could be attributed to the suitable band structures between the BiOCl/g-C3N4 composite with rich oxygen vacancies for the effective separation of photogenerated electron–hole pairs. [ABSTRACT FROM AUTHOR]