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A ceria loaded carbon nanotubes (CeO2/CNTs) nanocomposites photocatalyst was prepared by chemical precipitation, and the preparation conditions were optimized using an orthogonal experiment method. HR-TEM, XRD, UV-Vis/DRS, TGA and XPS were used to characterize the photocatalyst. Nitrogen adsorption-desorption was employed to determine the BET specific surface area. The results indicated that the photocatalyst has no obvious impurities. CeO2 was dispersed on the carbon nanotubes with a good loading effect and high loading efficiency without agglomeration. The catalyst exhibits a strong ability to absorb light in the ultraviolet region and some ability to absorb light in the visible light region. The CeO2/CNTs nanocomposites photocatalyst was used to degrade azo dye Acid Orange 7 (40 mg/L). The optical decolorization rate was 66.58% after xenon lamp irradiation for 4 h, which is better than that of commercial CeO2 (43.13%). The results suggested that CeO2 loading on CNTs not only enhanced the optical decolorization rate but also accelerated the separation of CeO2/CNTs and water.

To enhance the photocatalytic degradation efficiency and selectivity of di(2-ethyl)hexyl phthalate (DEHP), molecularly imprinted TiO2 (MIP-TiO2) was synthesized with di(2-ethylhexyl) phthalate as template molecule. The as-prepared MIP-TiO2 was characterized by Field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FI-IR), UV-Visible diffuse reflection spectroscopy (UV-Vis) and photoluminescence spectroscopy (PL). The selective adsorption and photocatalytic activity of MIP-TiO2 for DEHP were studied. The results show that DEHP molecularly imprinted polymer was coated on the surface of TiO2. The light-response of MIP-TiO2 was broadened. The photo-generated electron/hole recombination on the surface of TiO2 decreased. The selective recognition to DEHP was improved. Compared with TiO2, MIP-TiO2 exhibited higher photocatalytic activity and selectivity to DEHP. The photocatalytic degradation efficiency of DEHP (5mg/L) by MIP-TiO2 was 89%. The photocatalytic degradation rate of DEHP by MIP-TiO2 is 1.5 times that by TiO2. MIP-TiO2 could be reused.

Aiming at effectively controlling nonylphenol (NP) pollution, three bacterial strains were isolated from activated sludge and landfill leachate, which could grow with nonylphenol as sole carbon and energy source. The three nonylphenol-degrading bacteria isolated were named as WN6, SLY9 and SLY10, respectively. The morphological observation and 16S rDNA identification revealed that the strains belonged to Serratia sp., Klebsiella sp. and Pseudomonas putida, respectively. WN6 and SLY9 contained ALK gene, while WN6 and SLY10 harbored C12O genes. The three strains were combined together to form complex microorganisms ZJF. The ratio of Serratia sp. to Klebsiella sp. to Pseudomonas putida was 2:1:2 (volume ratio of bacterial suspension). Under the conditions that temperature was 30 ℃, pH was 6, inoculation amount was 10% (volume ratio), initial concentration of NP solutions was 20 mg/L, NP degradation rate by ZJF reached 73.82%, compared with any single strain of the three bacteria, NP degradation rate by ZJF increased more than 15% during 6 days. Bioremediation of nonylphenol-polluted the Yangtze River and the Ancient Canal water by ZJF ware simulated. After a 6-day incubation period, the degrading rate of nonylphenol in Ancient Canal water was close to 80%, and the degrading rate of nonylphenol in Yangtze River water was 72.84%.

A novel ternary heterojunction composite photocatalyst g-C3N4/TiO2/NiWO4 was fabricated using a simple hydrothermal method. The synthesized samples were characterized using X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy-dispersive spectrum (EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) absorption spectra, photoluminescence (PL) spectra, transient photocurrent responses, and electrochemical impedance spectroscopies (EIS). The results indicated that the composite of g-C3N4/TiO2/NiWO4 had been successfully synthesized. By constructing a ternary heterojunction, the electron migration rate and light absorption of the material are further improved; the photogenerated electron–hole recombination is inhibited. The ternary composite photocatalyst shows the highest photocatalytic activity for the degradation of rhodamine B (RhB) than that of g-C3N4, TiO2, NiWO4, and g-C3N4/TiO2 photocatalyst. The degradation efficiency of RhB using g-C3N4/TiO2/NiWO4 can reach 99% after visible-light irradiation for 40 min. Finally, the migration mechanism of charge carriers in the ternary system has been schematically illustrated by the active species capture experiment. Our research can pave the way for the fabrication of ternary heterojunction composite photocatalyst with high photocatalytic activity for the environmental contaminants treatment. [ABSTRACT FROM AUTHOR]

Summary: K-doped g-C3N4/SiO2composite (SiO2/K-CN) was synthesized by a facile thermal polymerization withpotassium chloride,melamine and nano-silica as raw materials. The as-prepared SiO2/K-CNwas characterized byvarious measures. The photocatalytic activity of SiO2/K-CNwastestedvia the photocatalyticdegradationoftetracycline undervisible-lightirradiation.The results showed that the specific surface area of SiO2/K-CNcatalyst was 28.16m2/g, which is larger than that of pristine K-doped g-C3N4. Both K-doping and silica-combinationcan reduce the recombination rate of photo-generatedelectrons-holespairs and broaden the region of visible light-harvesting.Compared with the pristine K-doped g-C3N4and composite SiO2/g-C3N4, SiO2/K-CN exhibits distinctly higher photocatalytic activity for degradation of tetracycline. The enhanced photocatalytic performance of SiO2/K-CN is attributed to the increasedspecific surface area and the synergistic effect of K-doping and silica-combination in both accelerating separation of charged carries and improving visible light-absorption. Duringphotocatalytic degradation of tetracycline, superoxide radicals play the most important role, followed by holes.SiO2/K-CNcomplex has excellentstability and shows promisingapplication in photocatalytic degradation of organic contaminants in water. [ABSTRACT FROM AUTHOR]

Improving the photocatalytic performance of metal-organic frameworks (MOFs) is an important way to expand its potential applications. In this work, zero-dimensional (0D) Bi 2 O 3 nanoparticles were anchored to the surface of tridimensional (3D) MIL101(Fe) by a facile solvothermal method to obtain a novel 0D/3D heterojunction Bi 2 O 3 /MIL101(Fe) (BOM). The morphology and optical properties of the as-prepared Bi 2 O 3 /MIL101(Fe) composite were characterized. The photocatalytic activity of the synthesized samples was evaluated by degrading chlortetracycline (CTC) under visible-light irradiation. The obtained BOM-20 composite (20 wt % Bi 2 O 3 /MIL101(Fe)) exhibits the highest photocatalytic activity with CTC degradation efficiency of 88.2% within 120 min. The degradation rate constant of BOM-20 toward CTC is 0.01348 min -1 , which is 5.9 and 4.3 times higher than that of pristine Bi 2 O 3 and MIL101(Fe), respectively. The enhanced photocatalytic activity is attributed to the formation of a Z-scheme heterojunction between Bi 2 O 3 and MIL101(Fe), which is conducive to the rapid separation of photogenerated carriers and the enhancement of photogenerated electron and hole redox capacity. The intermediate products were analyzed by liquid chromatography-mass spectrometry (LC-MS), and a possible photocatalytic degradation path of CTC was proposed. This work provides a new perspective for the preparation of efficient MOF-based photocatalysts., (Copyright © 2022, Hao et al.)

A spindle-like monoclinic-tetragonal heterojunction BiVO 4 was successfully synthesized by a pressure-controllable microwave method. The as-prepared BiVO 4 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, transient photocurrent responses and electrochemical impedance spectroscopy (EIS). The visible-light-driven photocatalytic activity of the BiVO 4 samples was evaluated for the degradation of Rhodamine B (RhB) and tetracycline (TC). The synthesis process needs microwave irradiation for only 10 min without the addition of any auxiliary reagent, pH adjustment, and calcination. The as-prepared spindle-like monoclinic-tetragonal heterojunction BiVO 4 exhibits excellent photocatalytic activity for the degradation of both RhB and TC. The photocatalytic degradation rates of RhB and TC over spindle-like BiVO 4 are 1.77 and 1.64 times higher, respectively, than that measured over monoclinic BiVO 4 . The enhanced photocatalytic activity is mainly attributed to the fact that the existence of a heterojunction effectively promotes the separation of photo-generated carriers and extends the visible-light absorption of BiVO 4 ., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)