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1.
This study aimed to investigate the tolerance of a melanized wild‐type strain of Aspergillus niger (CON1) and its light‐colored mutant (MUT1) to UV–C light and the concomitantly generated ozone. Treatments were segregated into four groups based on whether UV irradiation was used and the presence or absence of ozone: (?UV, ?O3), (?UV, +O3), (+UV, ?O3) and (+UV, +O3). The survival of CON1 and MUT1 conidia under +UV decreased as the exposure time increased, with CON1 showing greater resistance to UV irradiation than MUT1. Ozone induced CON1 conidium inactivation only under conditions of UV radiation exposure. While, the inactivation effect of ozone on MUT1 was always detectable regardless of the presence of UV irradiation. Furthermore, the CON1 conidial suspension showed lower UV light transmission than MUT1 when examined at the same concentration. Compared with the pigment in MUT1, the melanin in CON1 exhibited more potent radical‐scavenging activity and stronger UV absorbance. These results suggested that melanin protected A. niger against UV disinfection via UV screening and free radical scavenging. The process by which UV–C disinfection induces a continual decrease in conidial survival suggests that UV irradiation and ozone exert a synergistic fungicidal effect on A. niger prior to reaching a plateau.  相似文献   

2.
Ultraviolet light‐emitting diodes (UV‐LEDs) offer high flexibility in the reactor design for water disinfection. To specify the key design factors affecting the performance of a reactor, we examined how the arrangement of UV‐LEDs in a cylindrical reactor affects the inactivation efficiency of Escherichia coli and coliphage Qβ. A ring‐shaped UV‐LED apparatus, composed of two units containing ten 285‐nm UV‐LEDs each, were attached to a quartz cylinder, and microbial suspensions flowed through the cylinder for single pass at altered flow rates. The distance between the two units, L, was altered to examine its effects on inactivation efficiencies. Over 4 log inactivation of E. coli was achieved at 800 mL min?1 regardless of the L values, suggesting that the apparatus has a high potential to disinfect water. The inactivation at = 20 mm was significantly higher than that at = 0 in all cases tested (ANOVA,< 0.05), while this was not true when L was extended to 40 and 60 mm. Therefore, a separate arrangement of UV‐LEDs at a certain distance can improve the efficiency, and the distance matters to enhance the performance. This study involves a design concept on how to arrange UV‐LEDs in a water disinfection apparatus.  相似文献   

3.
The resistance to pulsed light (PL) of spores of Bacillus subtilis strain 168 and of strains with mutations increasing sensitivity to UV‐C or affecting spore structure was evaluated and compared to resistance to continuous UV‐C and moist heat, in order to reveal original mechanisms of inactivation by PL. Spores of B. subtilis strain 168 (1A1) and eight mutant strains (sspA, sspB, sspAB, cotA, gerE, cotE, uvrA and recA) were exposed to PL (up to 1.77 J cm?2), continuous UV‐C (up to 147 mJ cm?2) and moist heat at 90°C. Spores of the strains lacking proteins linked to coat formation or structure (cotA, gerE and cotE) were markedly more sensitive to PL than 1A1, while their sensitivity to continuous UV‐C or to moist heat was similar to the one of strain 1A1. Coat proteins had a major contribution to the resistance of B. subtilis spores to PL irradiation characterized by short‐time and high‐energy pulses of white light in the wavelengths 200–1100 nm. In contrast the role of coat proteins to UV‐C or to moist heat resistance was marginal or null.  相似文献   

4.
Using 1,10‐phenanothroline‐5,6‐dione and 10,20‐bis(4‐methylphenyl)porphyrin copper as starting materials, a conjugated porphyrin–imidazo[4,5‐f]‐1,10‐phenanothroline ligand (Por 1 ) was prepared. Subsequently, the copper complex of Por 1 was reacted with Ru(1,10‐phenanothroline)2Cl2 to yield ruthenium compound Por 2 . After removal of copper metal under acid condition, the free base porphyrin of Por 2 (Por 3 ) was prepared. The structure of these compounds was confirmed using UV–visible, 1H NMR, mass and infrared spectroscopies and elemental analysis. Through UV–visible, fluorescence and circular dichroism analyses, the interaction modes between Por 1 – 3 and calf thymus DNA were investigated. Por 1 interacted with DNA via outside groove face, but Por 2 and Por 3 showed intercalative interaction with DNA. Binding constants between Por 1 – 3 and DNA were 7.79 × 105, 1.29 × 106 and 1.32 × 106 M?1, respectively. With 5,10,15,20‐tetraphenylporphyrin (H2TPP) as a control, the singlet oxygen (1O2) generation of Por 1 – 3 was measured using the 1,3‐diphenylisobenzofuran method. The 1O2 generation rate of Por 1 – 3 followed the order: Por 3 >Por 1 >H2TPPP >Por 2 . Por 1 and Por 3 showed better 1O2 quantum yields than Por 2 , which were almost threefold higher than that of H2TPP. The DNA cleavage ability of Por 1 – 3 was analyzed using gel electrophoresis. Por 3 showed higher DNA photocleavage activity, with more than 50% photocleavage rate at 20 μM. These results suggest that amphipathic (hydrophilic/lipophilic) Por 3 with conjugated Por 1 ligand is a potential photosensitizer in cancer therapy.  相似文献   

5.
The current study is the first to delineate the contribution of photocatalysis to inactivation of Bacillus cereus endospores on dry surfaces over a broad range (0–153 W/m2) of UVA irradiance. Inactivation of spores at low UVA irradiance (30 W/m2) was primarily due to photocatalysis, whereas at higher UVA irradiance inactivation was primarily due to UV alone. A linear relationship between UVA irradiance and the rate of spore inactivation was observed in the absence of photocatalyst. The rate of photocatalytic inactivation was non-linear with respect to UVA irradiance, exhibiting a maximum at 30 W/m2.  相似文献   

6.
Photosynthetic bacteria are attractive for biotechnology because they produce no oxygen and so H2‐production is not inhibited by oxygen as occurs in oxygenic photoorganisms. Rhodopseudomonas palustris and Afifella marina containing BChl a can use irradiances from violet near‐UV (VNUV) to orange (350–650 nm) light and near‐infrared (NIR) light (762–870 nm). Blue diode‐based pulse amplitude modulation technology was used to measure their photosynthetic electron transport rate (ETR). ETR vs Irradiance curves fitted the waiting‐in‐line model—ETR = (ETRmax × E/Eopt) × exp (1 ? E/Eopt). The equation was integrated over pond depth to calculate ETR of Afifella and Rhodopseudomonas in a pond up to 30 cm deep (A376, 1 cm = 0.1). Afifella saturates at low irradiances and so photoinhibition results in very low photosynthesis in a pond. Rhodopseudomonas saturates at ≈15% sunlight and shows photoinhibition in the surface layers of the pond. Total ETR is ≈335 μmol (e?) m?2 s?1 in NUV + photosynthetically active radiation light (350–700 nm). Daily ETR curves saturate at low irradiances and have a square‐wave shape: ≈11–13 mol (e?) m?2 day?1 (350–700 nm). Up to 20–24% of daily 350–700 nm irradiance can be converted into ETR. NIR is absorbed by water and so competes with the bacterial RC‐2 photosystem for photons.  相似文献   

7.
Two new compounds ( 1 and 2 ) containing 2‐sulfydryl‐1,3,4‐thiodiazole have been synthesized and optimized. They both showed wide antibacterial activity for colon bacillus, Staphylococcus aureus, S. albus, dysentery bacillus and inferior activity for Bacillus subtilis. In addition, their binding properties were evaluated for biologically important anions (F, Cl, Br, I, AcO, and H2PO4) by theoretical investigation, UV–vis, fluorescence, and 1H NMR titration experiments, and they displayed strong binding ability for H2PO4 without the interference of other anions tested. Especially the binding ability of compound 2 containing anthracene with H2PO4 was 1000 times stronger than that of compound 1 containing nitrobenzene. Two compounds based on 2‐sulfydryl‐1,3,4‐thiodiazole have both properties of anion recognition and antibacterial activity.  相似文献   

8.
Novel multifunctional photosensitizers (MFPSs), 5,10,15‐tris(4‐N‐methylpyridinium)‐20‐(4‐phenylthio)‐[21H,23H]‐porphine trichloride (PORTH) and 5,10,15‐tris(4‐N‐methylpyridinium)‐20‐(4‐(butyramido‐methylcysteinyl)‐hydroxyphenyl)‐[21H,23H]‐porphine trichloride (PORTHE), derived from 5,10,15‐Tris(4‐methylpyridinium)‐20‐phenyl‐[21H,23H]‐porphine trichloride (Sylsens B) and designed for treatment of onychomycosis were characterized and their functionality evaluated. MFPSs should function as nail penetration enhancer and as photosensitizer for photodynamic treatment (PDT) of onychomycosis. Spectrophotometry was used to characterize MFPSs with and without 532 nm continuous‐wave 5 mW cm?2 laser light (± argon/mannitol/NaN3). Nail penetration enhancement was screened (pH 5, pH 8) using water uptake in nails and fluorescence microscopy. PDT efficacy was tested (pH 5, ± argon/mannitol/NaN3) in vitro with Trichophyton mentagrophytus microconida (532 nm, 5 mW cm?2). A light‐dependent absorbance decrease and fluorescence increase were found, PORTH being less photostable. Argon and mannitol increased PORTH and PORTHE photostability; NaN3 had no effect. PDT (0.6 J cm?2, 2 μm ) showed 4.6 log kill for PORTH, 4.4 for Sylsens B and 3.2 for PORTHE (4.1 for 10 μm ). Argon increased PORTHE, but decreased PORTH PDT efficacy; NaN3 increased PDT effect of both MFPSs whereas mannitol increased PDT effect of PORTHE only. Similar penetration enhancement effects were observed for PORTH (pH 5 and 8) and PORTHE (pH 8). PORTHE is more photostable, effective under low oxygen conditions and thus realistic candidate for onychomycosis PDT.  相似文献   

9.
Mononuclear nickel(II) complexes were prepared by reaction of the three ONNO type reduced Schiff bases bis‐N,N′‐(2‐hydroxybenzyl)‐1,3‐propanediamine (LHH2), bis‐N,N′‐(2‐hydroxybenzyl)‐2,2′‐dimethyl‐1,3‐propanediamine (LDMHH2), and bis‐N,N′‐[1‐(2‐hydroxyphenyl)ethyl]‐1,3‐propanediamine (LACHH2) with NiII ions in the presence of pseudo halides (OCN, SCN and N3). The complexes were characterized with the use of elemental analyses, IR spectroscopy, and thermal analyses. The molecular structure of one of the complexes was obtained by single‐crystal X‐ray diffraction. The obtained complexes are mononuclear, and a pseudo halide molecule is attached. One of the oxygen atoms of the ligand is in phenolate and the other was in phenol form. According to the thermogravimetry results, it was thought that the pseudo halide thermally detaches from the structure as hydropseudo halide. In azide‐containing complexes an endothermic reaction was observed although the azide group usually decomposes with an exothermic reaction.  相似文献   

10.
A novel Prussian blue (PB)‐Fe3O4 composite has been prepared for the first time by self‐template method using PB as the precursor. According to this method, Fe3O4 nanoparticles distributed uniformly on the surface of PB cube. The feed ratio of sodium acetate to PB has been proved to be a key factor for magnetic properties and electro‐catalysis properties of the composite. Under the experimental conditions, the saturation magnetization value (Ms) of PB‐Fe3O4–2 composite was 22 emug?1, while the Ms value of other samples reduced. The composites also showed a good peroxidase‐like activity for the oxidation of substrate 3,3,5,5‐tetramethylbenzidine (TMB) in the presence of H2O2. The catalytic reduction of hydrogen peroxide capacity was PB‐Fe3O4–1> PB‐Fe3O4–2> PB‐Fe3O4–3> PB‐Fe3O4–0, which confirmed the Fe(II) centres in PB surface and Fe3O4 nanoparticles had synergistic effect on catalytic reduction of hydrogen peroxide.  相似文献   

11.
Blue diode‐based pulse amplitude modulation (PAM) technology can be used to measure the photosynthetic electron transport rate (ETR) in a purple nonsulfur anoxygenic photobacterium, Afifella (Rhodopseudomonas) marina. Rhodopseudomonads have a reaction center light harvesting antenna complex containing an RC‐2 type bacteriochlorophyll a protein (BChl a RC‐2‐LH1) which has a blue absorption peak and variable fluorescence similar to PSII. Absorptance of cells filtered onto glass fiber disks was measured using a blue–diode‐based absorptance meter (Blue‐RAT) so that absolute ETR could be calculated from PAM experiments. Maximum quantum yield (Y) was ≈0.6, decreasing exponentially as irradiance increased. ETR vs irradiance (P vs E) curves fitted the waiting‐in‐line model (ETR = (ETRmax × E/Eopt) × exp(1 ? E/Eopt)). Maximum ETR (ETRmax) was ≈1000–2000 μmol e? mg?1 BChl a h?1. Fe2+, bisulfite and thiosulfate act as photosynthetic electron donors. Optimum irradiance was ≈100 μmol m?2 s?1 PPFD even in Afifella grown in sunlight. Quantum efficiencies (α) were ≈0.3–0.4 mol e? mol hλ?1; or ≈11.8 ± 2.9 mol e? mol hλ?1 m2 μg?1 BChl a). An underlying layer of Afifella in a constructed algal/photosynthetic bacterial mat has little effect on the measured ETR of the overlying oxyphotoautotroph (Chlorella).  相似文献   

12.
The kinetics of the oxidation of promazine (PMZ) by hydrogen peroxide was studied in the presence of a large excess of H2O2 in acidic chloride media using UV–vis spectroscopy. The reaction proceeds via two consecutive steps. In the first step, oxidation leads to formation of a promazine radical. In the second step, the promazine radical is oxidized to promazine 5‐oxide. Electron paramagnetic resonance spectroscopy (EPR) results provide clear evidence for the formation of an intermediate promazine radical. Linear dependences of the pseudo‐first‐order rate constants (k1 and k2) on [H2O2] with a nonzero intercept were established for the first and the second process, respectively. The rate of the first stage of the reaction increased slightly with increasing concentration of O2, indicating the role of the OH? radicals on the redox process, which are transformed into the Cl radicals. The mechanism of the overall reaction is discussed on the basis of all these kinetic measurements. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 1–9, 2010  相似文献   

13.
The efficacy of UV and vacuum-UV (VUV) disinfection of Bacillus subtilis spores in aqueous suspensions at wavelengths of 172, 222 and 254 nm was evaluated. A Xe2* excilamp, a KrCl* excilamp and a low-pressure mercury lamp were used as almost monochromatic light sources at these three wavelengths. The first-order inactivation rate constants at 172, 222 and 254 nm were 0.0023, 0.122 and 0.069 cm2 mJ−1, respectively. Therefore, a 2 log reduction of B .  subtilis spores was reached with fluences (UV doses) of 870, 21.6 and 40.4 mJ cm−2 at these individual wavelengths. Consequently, for the inactivation of B .  subtilis spores, VUV exposure at 172 nm is much less efficient than exposure at the other two wavelengths, while exposure at 222 nm is more efficient than that at 254 nm, which is probably because triplet energy transfer from DPA to thymine bases at 222 nm is higher than that at 254 nm. This research indicated quantitatively that VUV light is not practicable for microorganism disinfection in water and wastewater treatment. However, in comparison with other advanced oxidation processes ( e.g. UV/TiO2, UV/H2O2 or O3/H2O2) the VUV-initiated photolysis of water is likely more efficient in generating hydroxyl radicals and more effective for the inactivation of microorganisms.  相似文献   

14.
Two new coordination polymers (CPs) formed from 5‐iodobenzene‐1,3‐dicarboxylic acid (H2iip) in the presence of the flexible 1,4‐bis(1H‐imidazol‐1‐yl)butane (bimb) auxiliary ligand, namely poly[[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′](μ3‐5‐iodobenzene‐1,3‐dicarboxylato‐κ4O1,O1′:O3:O3′)cobalt(II)], [Co(C8H3IO4)(C10H14N4)]n or [Co(iip)(bimb)]n, (1), and poly[[[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′](μ2‐5‐iodobenzene‐1,3‐dicarboxylato‐κ2O1:O3)zinc(II)] trihydrate], {[Zn(C8H3IO4)(C10H14N4)]·3H2O}n or {[Zn(iip)(bimb)]·3H2O}n, (2), were synthesized and characterized by FT–IR spectroscopy, thermogravimetric analysis (TGA), solid‐state UV–Vis spectroscopy, single‐crystal X‐ray diffraction analysis and powder X‐ray diffraction analysis (PXRD). The iip2− ligand in (1) adopts the (κ11‐μ2)(κ1, κ1‐μ1)‐μ3 coordination mode, linking adjacent secondary building units into a ladder‐like chain. These chains are further connected by the flexible bimb ligand in a transtranstrans conformation. As a result, a twofold three‐dimensional interpenetrating α‐Po network is formed. Complex (2) exhibits a two‐dimensional (4,4) topological network architecture in which the iip2− ligand shows the (κ1)(κ1)‐μ2 coordination mode. The solid‐state UV–Vis spectra of (1) and (2) were investigated, together with the fluorescence properties of (2) in the solid state.  相似文献   

15.
Reaction of N,N′‐(cyclohexane‐1,2‐diylidene)bis(4‐fluorobenzohydrazide), C20H18F2N4O2, ( LF ), with zinc chloride and mercury(II) chloride produced different types and shapes of neutral coordination complexes, namely, dichlorido[N,N′‐(cyclohexane‐1,2‐diylidene)bis(4‐fluorobenzohydrazide)‐κ2N,O]zinc(II), [ZnCl2(C20H18F2N4O2)], ( 1 ), and dichlorido[N,N′‐(cyclohexane‐1,2‐diylidene)bis(4‐fluorobenzohydrazide)‐κ4O,N,N′,O′]mercury(II), [HgCl2(C20H18F2N4O2)], ( 2 ). The organic ligand and its metal complexes are characterized using various techniques: IR, UV–Vis and nuclear magnetic resonance (NMR) spectroscopies, in addition to powder X‐ray diffraction (PXRD), single‐crystal X‐ray crystallography and microelemental analysis. Depending upon the data from these analyses and measurements, a typical tetrahedral geometry was confirmed for zinc complex ( 1 ), in which the ZnII atom is located outside the bis(benzhydrazone) core. The HgII atom in ( 2 ) is found within the core and has a common octahedral structure. The in vitro antibacterial activities of the prepared compounds were evaluated against two different bacterial strains, i.e. gram positive Bacillus subtilis and gram negative Pseudomonas aeruginosa bacteria. The prepared compounds exhibited differentiated growth‐inhibitory activities against these two bacterial strains based on the difference in their lipophilic nature and structural features.  相似文献   

16.
A new Schiff base ligand (HL) was prepared via a condensation reaction of quinoline‐2‐carboxaldhyde with 2‐aminophenol in a molar ratio of 1:1. Its transition metal mixed ligand complexes with 1,10‐phenanthroline (1,10‐phen) as co‐ligand were also synthesized in a 1:1:1 ratio. HL and its mixed ligand complexes were characterized using elemental analysis, infrared, 1H NMR, mass and UV–visible spectroscopies, molar conductance, magnetic measurements, solid reflectance, thermal analysis, electron spin resonance and X‐ray diffraction. Molar conductance measurements showed that all complexes have an electrolytic nature, except Cd(II) complex. From elemental and spectral data, the formulae [M(L)(1,10‐phen)(H2O)]Clx?nH2O (where M = Cr(III) (x = n = 2), Mn(II) and Ni(II) (x = 1, n = 2), Fe(III) (x = n = 2), Co(II), Cu(II) and Zn(II) (x = 1, n = 2)) and [Cd(L)(1,10‐phen)Cl]?3H2O for the metal complexes have been proposed. The geometric structures of complexes were found to be octahedral. Powder X‐ray diffraction reflected the crystalline nature of the complexes; however, the Schiff base is amorphous. HL and its mixed ligand complexes were screened against Gram‐positive bacteria (Streptococcus pneumoniae and Bacillus subtilis) and Gram‐negative bacteria (Pseudomonas aeruginosa and Escherichia coli). Antifungal activity was determined against Aspergillus fumigatus and Candida albicans, the data showing that most complexes had activity less than that of the Schiff base while Mn(II), Fe(III) and Ni(II) complexes showed no significant antifungal activity. The anticancer activity of HL and its metal complexes was also studied against breast and colon cell lines. The metal complexes showed IC50 higher than that of HL, especially the Cu(II) complex which showed the highest IC50 against breast cell line.  相似文献   

17.
Ultraviolet‐B radiation (280–320 nm) has long been associated with the inactivation of microorganisms in the natural environment. Determination of the environmental inactivation kinetics of specific indicator organisms [used as tools in the field of microbial source tracking (MST)] is fundamental to their successful deployment, particularly in geographic regions subject to high levels of solar radiation. Phage infecting Bacteroides fragilis host strain GB124 (B124 phage) have been demonstrated to be highly specific indicators of human fecal contamination, but to date, little is known about their susceptibility to UV‐B radiation. Therefore, B124 phage (= 7) isolated from municipal wastewater effluent, were irradiated in a controlled laboratory environment using UV‐B collimated beam experiments. All B124 phage suspensions possessed highly similar first order log‐linear inactivation profiles and the mean fluence required to inactivate phage by 4 ? log10 was 320 mJ cm?2. These findings suggest that phage infecting GB124 are likely to be inactivated when exposed to the levels of UV‐B solar radiation experienced in a variety of environmental settings. As such, this may limit the utility of such methods for determining more remote inputs of fecal contamination in areas subject to high levels of solar radiation.  相似文献   

18.
In the salt trimethoprimium ferrocenecarboxylate [systematic name: 2,4‐diamino‐5‐(3,4,5‐trimethoxybenzyl)pyrimidin‐1‐ium ferrocene‐1‐carboxylate], (C14H19N4O3)[Fe(C5H5)(C6H4O2)], (I), of the antibacterial compound trimethoprim, the carboxylate group interacts with the protonated aminopyrimidine group of trimethoprim via two N—H…O hydrogen bonds, generating a robust R 22(8) ring motif (heterosynthon). However, in the cocrystal 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–ferrocene‐1‐carboxylic acid (1/1), [Fe(C5H5)(C6H5O2)]·C6H8ClN3, (II), the carboxyl–aminopyrimidine interaction [R 22(8) motif] is absent. The carboxyl group interacts with the pyrimidine ring via a single O—H…N hydrogen bond. The pyrimidine rings, however, form base pairs via a pair of N—H…N hydrogen bonds, generating an R 22(8) supramolecular homosynthon. In salt (I), the unsubstituted cyclopentadienyl ring is disordered over two positions, with a refined site‐occupation ratio of 0.573 (10):0.427 (10). In this study, the two five‐membered cyclopentadienyl (Cp) rings of ferrocene are in a staggered conformation, as is evident from the C…Cg Cg …C pseudo‐torsion angles, which are in the range 36.13–37.53° for (I) and 22.58–23.46° for (II). Regarding the Cp ring of the minor component in salt (I), the geometry of the ferrocene ring is in an eclipsed conformation, as is evident from the C…Cg Cg …C pseudo‐torsion angles, which are in the range 79.26–80.94°. Both crystal structures are further stabilized by weak π–π interactions.  相似文献   

19.
Samples of natural groundwater (with low turbidity, neutral pH and 0.3 mg L?1 iron concentration) inoculated with Escherichia coli K‐12 were exposed to simulated solar light both in the presence and in the absence 10 mg L?1 of H2O2. Results demonstrated that the viability of E. coli (by DVC–FISH) was grounded to zero after 360 min of irradiation. This abatement could be caused by the oxidative stress induced by radicals or another photo‐induced reactive oxygen species. Two 23 factorial experimental designs enabled the evaluation of the effects of chemical factors on the inactivation of E. coli. The first experimental design considered the pH, iron and H2O2, while the second evaluated the ions fluoride, carbonate and phosphate found in groundwater. pH was found to play a key role in the inactivation of E. coli. The best reduction in viability was obtained at the lower pH (6.75), while a nonsignificant effect was observed when iron or H2O2 concentrations were raised. At higher concentrations, anions, such as carbonate and phosphate, negatively affected the E. coli abatement. However, a higher concentration of fluoride accelerated it. In all experiments, the pH was observed to rise to values higher than 8.0 units after 360 min of treatment.  相似文献   

20.
A magnetized nano‐photocatalyst based on TiO2/magnetic graphene was developed for efficient photodegradation of crystal violet (CV). Scanning electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy and elemental mapping were used to characterize the prepared magnetic nano‐photocatalyst. The photocatalytic activity of the synthesized magnetic nano‐photocatalyst was evaluated using the decomposition of CV as a model organic pollutant under UV light irradiation. The obtained results showed that TiO2/magnetic graphene exhibited much higher photocatalytic performance than bare TiO2. Incorporation of graphene enhanced the activity of the prepared magnetic nano‐photocatalyst. TiO2/magnetic graphene can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, magnetized nano‐photocatalyst dosage, UV light irradiation time, H2O2 amount and initial concentration of dye on the photodegradation efficiency were evaluated and optimized. Efficient photodegradation (>98%) of the selected dye under optimized conditions using the synthesized nano‐photocatalyst under UV light irradiation was achieved in 25 min. The prepared magnetic nano‐photocatalyst can be used in a wide pH range (4–10) for degradation of CV. The effects of scavengers, namely methanol (OH? scavenger), p‐benzoquinone (O2?? scavenger) and disodium ethylenediaminetetraacetate (hole scavenger), on CV photodegradation were investigated.  相似文献   

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