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Luminescent perovskite photocatalysts activated by Pr3+ were prepared by combustion. The structural phase, morphology, and chemical composition of the as-prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, and ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy. The photocatalytic activities of the synthesized samples were investigated on the basis of the degradation of methylene blue (MB) under UV light irradiation. CaTiO3:Pr3+ was obtained in high purity and good crystallinity with a perovskite structure. The degradation of the photocatalyst was fitted with pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. Compared to CaTiO3:Pr3+, Ca1–xTiO3:Pr3+ (x = 0–0.3) multifunctional materials exhibit higher luminescence intensity and photocatalytic activity toward the degradation of MB. Ca0.8TiO3:0.1%Pr3+ exhibited the best performance. [ABSTRACT FROM AUTHOR]

Praseodymium-doped perovskite Functional mineral material was synthesized via the combustion method. The crystal structure and morphologies were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The photocatalytic performance was studied by the degradation experiment of inferior methyl blue. The results indicate that CaTiO3 has good photocatalytic degradation performance for the inferior methyl blue under UV-irradiation condition and the Pr3+-doping significantly improved the photocatalytic efficiency. The degradation rate of MB decreased with the increasing initial concentration. Furthermore, The degradation rate of MB increased first and then decreased with the increasing concentration of catalyzer. [ABSTRACT FROM AUTHOR]

Ytterbium-doped titanium dioxide (Yb-TiO 2 )/diatomite composite materials with different Yb concentrations were prepared by sol–gel method. The phase structure, morphology, and chemical composition of the as-prepared composites were well characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and ultraviolet–visible (UV–vis) diffuse reflection spectroscopy. The XRD and Raman spectroscopy analysis indicated that the TiO 2 existed in the form of pure anatase in the composites. The SEM images exhibited the well deposition and dispersion of TiO 2 nanoparticles with little agglomeration on the surfaces of diatoms. The UV–vis diffuse reflection spectra showed that the band gap of TiO 2 could be narrowed by the introduction of Yb species, which was further affected by doping concentration of Yb. The photocatalytic activity of synthesized samples was investigated by the degradation of methylene blue (MB) under UV light irradiation. It was observed that the photocatalytic degradation followed a pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. Compared to TiO 2 and TiO 2 /diatomite, the Yb-TiO 2 /diatomite composites exhibited higher photocatalytic activity toward degradation of MB using UV light irradiation. [ABSTRACT FROM AUTHOR]

Praseodymium-doped perovskite Functional mineral material was synthesized via the combustion method. The crystal structure and morphologies were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The photocatalytic performance was studied by the degradation experiment of inferior methyl blue. The results indicate that CaTiO3 has good photocatalytic degradation performance for the inferior methyl blue under UV-irradiation condition and the Pr3+-doping significantly improved the photocatalytic efficiency. The degradation rate of MB decreased with the increasing initial concentration. Furthermore, The degradation rate of MB increased first and then decreased with the increasing concentration of catalyzer. [ABSTRACT FROM AUTHOR]

[Display omitted] • In situ construction of multiphase through controlled hydrothermal and oxidation. • High efficiency by increasing Fe ions adsorbed and constructing p-n junction. • Material with efficient synergistic degradation of Cr(VI) and MO. In this study, the magnetic composite particles composed of marcasite, pyrite, and magnetite were prepared with the hydrothermal process and oxidation. The coexistence of marcasite and pyrite was achieved by controlling the sulfur content in the hydrothermal process, and surface magnetite was realized by controllable oxidation. The typical composite particles presented the regular spherical size of 5 to 7 μm and could degrade 41.2 % MO as well as reduce 98 % Cr(VI). In the mixed solution of MO/Cr(VI), the synergistic degradation rate of MO increased from 41.2 % to 70.5 % and the reduction rate of Cr(VI) could still reach 98 %. Multiphase recombination could increase Fe adsorbed on the material surface and construct the p-n junction. In addition, surface magnetite endowed the material with magnetic recyclability. In situ multiphase recombination turned cheap FeS 2 into a valuable treatment agent for mixed pollutants. [ABSTRACT FROM AUTHOR]

In order to solve the pollution of heavy metals and organic antibiotic in the water environment, a novel CuBi 2 O 4 /calcined ZnAlBi layered double hydroxides (CBO/CLDHs) composite was constructed and prepared via an ultrasonic-assisted calcination method for the adsorption and photocatalysis synergetic effect. Through varying the composition ratio, pH value, initial pollutant concentration and other pollutant interference, the simultaneous removal ability including adsorption and photocatalysis of as-prepared CBO/CLDHs composites for Cr(VI) and tetracycline pollutants was discussed. In particular, the CBO/CLDHs-1/15 composite showed that the removal efficiencies of Cr(VI) (40 mg/L) and tetracycline (40 mg/L) were both above 95%. Meanwhile, the XPS results confirmed that the toxic Cr(VI) was gradually reduced to non-toxic Cr(III) under visible light irradiation. The enhanced adsorption and photocatalytic activity was mainly attributed to the uniform distribution of calcined ZnAlBi layered double hydroxides nanosheets on the CuBi 2 O 4 microrods and the formation of heterojunctions. Moreover, cycle performance results revealed that the CBO/CLDHs-1/15 composite maintained high removal activity and stable structure after 4 photocatalytic cycles, and even showed a good adaptability while applied to the actual water in production and living environments. These results exhibited that the as-prepared CBO/CLDHs-1/15 composite has excellent adsorption and photocatalytic ability for the simultaneous removal of Cr(VI) and tetracycline, with a great potential application in practical waste water treatment field. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Co2+-doped ZnO nanoarrays was first grown on substrate and used as photocatalyst. • Co2+ was doped to improve the photocatalytic activity under visible-light induction. • Co2+-doped ZnO efficiently remove organic pollutants for environmental protection. In order to remove the organic pollution from water environment, Co2+-doped ZnO nanoarray photocatalyst was prepared through a hydrothermal process. The influences of Co2+ doping amount and hydrothermal temperature on the nanostructure and photocatalytic performance of Co2+-doped ZnO nanoarray were discussed in detail. The standard ZnO structure and nanoarray morphology of Co2+-doped ZnO samples were achieved and the absorption of visible light was also realized through Co2+ doping. The 2% Co2+-doped ZnO nanoarray prepared at 95 °C exhibited excellent photocatalytic activity and could degrade 96% of methylene blue solution within 120 min under visible light. Furthermore, the as-prepared 2% Co2+-doped ZnO nanoarray still maintained 91% for removal rate after 3 cycles of photocatalytic degradation, showed good photocatalytic activity and recyclability. All results indicate that ZnO nanoarray with Co2+ doping has a potential application in visible light photocatalysis for environmental protection and pollution control. [ABSTRACT FROM AUTHOR]