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1.
Background and Purpose
Microcystin-LR (MC-LR), a common toxic species in contaminated aquatic systems, persists for long periods because of its cyclic structure. Ag3PO4 is an environment-friendly photocatalyst with relatively good degradation capacity for hazardous organic pollutants. This study aimed to investigate the degradation capacity of Ag3PO4 for MC-LR under visible light.Methods
An Ag3PO4 photocatalyst was synthesized by the ion-exchange method and characterized by X-ray diffraction, field-emission scanning electron microscope, and UV-Vis spectrophotometer. MC-LR was quantified in each sample through high-performance liquid chromatograph. The degradation efficiency of MC-LR was affected by initial pH, initial Ag3PO4 concentration, initial MC-LR concentration, and recycle experiments. The degradation intermediates of MC-LR were examined by liquid chromatography-mass spectrometry (LC/MS).Results
The degradation process can be well fitted with the pseudo-first-order kinetic model. The maximum MC-LR degradation rate of 99.98% can be obtained within 5 h under the following optimum conditions: pH of 5.01, Ag3PO4 concentration of 26.67 g/L, and MC-LR concentration of 9.06 mg/L. Nine intermediates were detected and analyzed by LC/MS. Three main degradation pathways were proposed based on the molecular weight of the intermediates and the reaction mechanism: (1) hydroxylation on the aromatic ring of Adda, (2) hydroxylation on the diene bonds of Adda, and (3) internal interactions on the cyclic structure of MC-LR.Conclusion
Ag3PO4 is a highly efficient catalyst for MC-LR degradation in aqueous solutions. 相似文献2.
1. The effect of phosphate on the oxidation of glyceric aldehyde by methylene blue, 1-naphthol 2-sulfonate indophenol, and phenol-indophenol has been studied. 2. At pH 4.77 in a phthalate-buffered medium phosphate does not catalyze the reaction. 3. At pH 7.9 in solutions buffered with borate, carbonate, or phenylalanine marked catalysis by phosphate is observed. The effect is most pronounced in borate. 4. Phosphate catalysis, within the limits studied, is strictly a linear function of the phosphate concentration. 5. The high concentration of HPO4
= and the low concentration of PO4
≡ relative to that of the substrate virtually demand the conclusion that the PO4
≡ ion is the active catalytic species. 相似文献
3.
Kamala Mitra Abhisek Brata Ghosh Arpita Sarkar Namrata Saha Amit Kumar Dutta 《Biochemical and biophysical research communications》2014
This article reports simple, green and efficient synthesis of γ-Fe2O3 nanoparticles (NPs) (maghemite) through single-source precursor approach for colorimetric estimation of human glucose level. The γ-Fe2O3 NPs, having cubic morphology with an average particle size of 30 nm, exhibited effective peroxidase-like activity through the catalytic oxidation of peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 producing a blue-colored solution. On the basis of this colored-reaction, we have developed a simple, cheap, highly sensitive and selective colorimetric method for estimation of glucose using γ-Fe2O3/TMB/glucose–glucose oxidase (GOx) system in the linear range from 1 to 80 μM with detection limit of 0.21 μM. The proposed glucose sensor displays faster response, good stability, reproducibility and anti-interference ability. Based on this simple reaction process, human blood and urine glucose level can be monitored conveniently. 相似文献
4.
Jun Sumaoka Kenichiro Furuki Yuki Kojima Masahiko Shibata Kimihiko Hirao Naoya Takeda 《Nucleosides, nucleotides & nucleic acids》2013,32(4-6):523-538
The hydrolysis of cyclic adenosine 3′,5′-monophosphate and 2′-deoxythymidylyl(3′-5′)2′-deoxythymidine by Ce(NH4)2(NO3)6 was kinetically studied. The rate of hydrolysis was fairly proportional to the concentration of [Ce IV 2 (OH)4]4+, showing that this is the catalytically active species. According to quantum-chemical calculation, the two Ce(IV) ions in this [CeIV 2(OH)4]4+ cluster are bridged by two OH residues. Upon the complex formation with H2 PO4 ? (a model compound for the phosphodiesters), these two Ce(IV) ions bind the two oxygen atoms of the substrate and enhance the electrophilicity of the phosphorus atom. The catalytic mechanism of Ce(IV)-induced hydrolysis of phosphodiesters has been proposed on the basis these results. 相似文献
5.
The acid-catalysed, aqueous phase dehydration of xylose (a monosaccharide obtainable from hemicelluloses, e.g., xylan) to furfural was investigated using vanadium phosphates (VPO) as catalysts: the precursors, VOPO4·2H2O, VOHPO4·0.5H2O and VO(H2PO4)2, and the materials prepared by calcination of these precursors, that is, γ-VOPO4, (VO)2P2O7 and VO(PO3)2, respectively. The VPO precursors were completely soluble in the reaction medium. In contrast, the orthorhombic vanadyl pyrophosphate (VO)2P2O7, prepared by calcination of VOHPO4·0.5H2O at 550 °C/2 h, could be recycled by simply separating the solid acid from the reaction mixture by centrifugation, and no drop in catalytic activity and furfural yields was observed in consecutive 4 h-batch runs (ca. 53% furfural yield, at 170 °C). However, detailed catalytic/characterisation studies revealed that the vanadyl pyrophosphate acts as a source of active water-soluble species in this reaction. For a concentration of (VO)2P2O7 as low as 5 mM, the catalytic reaction of xylose (ca. 0.67 M xylose in water, and toluene as solvent for the in situ extraction of furfural) gave ca. 56% furfural yield, at 170 °C/6 h reaction. 相似文献
6.
Polyoxometalates (H(3)PW(12)O(40), H(4)SiW(12)O(40) and H(3)PMo(12)O(40)) have been proven to possess intrinsic peroxidase-like activity for the first time, which can catalyze oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) by H(2)O(2) to form a blue color in aqueous solution. Among them, H(3)PW(12)O(40) (PW(12)) exhibits higher catalytic activity to TMB than natural enzyme HRP and other two POMs. In addition, H(3)PW(12)O(40)/graphene exhibited higher activity than H(3)PW(12)O(40) in this catalytic oxidation reaction due to the effect of graphene in promoting the electron transfer between the substrate and catalyst. POMs/H(2)O(2)/TMB system provides a simple, accurate approach to colorimetric detection for H(2)O(2) or glucose. The colorimetric method based on POMs showed good response toward H(2)O(2) and glucose detection with a linear range from 1.34×10(-7) to 6.7×10(-5) mol/L and 1×10(-7) to 1×10(-4) mol/L, respectively. The results showed that it is a simple, cheap, more convenient, highly selective, sensitive, and easy handling colorimetric assay. 相似文献
7.
Joel L. Asenjo Heide C. Ludwig Cristian A. Droppelmann Juan G. Cárcamo Ilona I. Concha Alejandro J. Yáñez María L. Cárdenas Athel Cornish-Bowden Juan C. Slebe 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014
Background
Fructose-1,6-bisphosphatase, a major enzyme of gluconeogenesis, is inhibited by AMP, Fru-2,6-P2 and by high concentrations of its substrate Fru-1,6-P2. The mechanism that produces substrate inhibition continues to be obscure.Methods
Four types of experiments were used to shed light on this: (1) kinetic measurements over a very wide range of substrate concentrations, subjected to detailed statistical analysis; (2) fluorescence studies of mutants in which phenylalanine residues were replaced by tryptophan; (3) effect of Fru-2,6-P2 and Fru-1,6-P2 on the exchange of subunits between wild-type and Glu-tagged oligomers; and (4) kinetic studies of hybrid forms of the enzyme containing subunits mutated at the active site residue tyrosine-244.Results
The kinetic experiments with the wild-type enzyme indicate that the binding of Fru-1,6-P2 induces the appearance of catalytic sites with lower affinity for substrate and lower catalytic activity. Binding of substrate to the high-affinity sites, but not to the low-affinity sites, enhances the fluorescence emission of the Phe219Trp mutant; the inhibitor, Fru-2,6-P2, competes with the substrate for the high-affinity sites. Binding of substrate to the low-affinity sites acts as a “stapler” that prevents dissociation of the tetramer and hence exchange of subunits, and results in substrate inhibition.Conclusions
Binding of the first substrate molecule, in one dimer of the enzyme, produces a conformational change at the other dimer, reducing the substrate affinity and catalytic activity of its subunits.General significance
Mimics of the substrate inhibition of fructose-1,6-bisphosphatase may provide a future option for combatting both postprandial and fasting hyperglycemia. 相似文献8.
Grochala W 《Journal of molecular modeling》2011,17(9):2237-2248
The DFT calculations performed within local density approximation disclose conceivable existence of two novel mixed–valence
Ag(I)/Ag(II) fluorides, Ag2F3, i.e., Ag(I)Ag(II)F3 and Ag3F4, i.e., Ag(I)2Ag(II)F4. Ag2F3 is predicted to crystallize in three equally stable NaCuF3–, KAgF3–, or CuTeO3–type structures, while Ag3F4 should be isostructural to Na2CuF4. The calculated vibration-corrected energies of formation at 0 K of Ag2F3 and Ag3F4 (in their most stable polytypes) from binary fluorides are negative but small (respectively, –0.09 eV and –0.21 eV per formula
unit). Formation of Ag3F5 (which, in fact, is a mixed valence Ag(I)/Ag(III) salt) from binary fluorides is much less likely, since the energy of formation
is quite positive of about a quarter eV. The predicted volumes per formula unit for all forms of Ag2F3 are larger and that for K2CuF4–type Ag3F4 is smaller than the sum of volumes of the corresponding binary fluorides; Ag2F3 should not form at high pressure conditions due to a decomposition to the binary constituents. Ag2F3 and Ag3F4 should exhibit genuine mixed– and not intermediate–valence with quite different coordination spheres of Ag(I) and Ag(II).
Nevertheless, they should not be electric insulators. Ag2F3 is predicted to be a metallic ferrimagnet with a magnetic superexchange coupling constant, J, of –2 meV while Ag3F4 should be a metallic ferromagnet with J of +52 meV. Since Ag2F3 and Ag3F4 are at the verge of thermodynamic stability, a handful of exothermic reactions have been proposed which could yield these
as yet unknown compounds. 相似文献
9.
A Ros Barceló 《Journal of plant research》1999,112(4):383-390
Zinnia elegans stems with 3,3′, 5, 5′-tetramethylbenzidine (TMB) in the presence and in the absence of catalase reveals the presence of
xylem oxidase activities in the H2O2-producing lignifying xylem cells. This staining of lignifying xylem cells with TMB is the result of two independent mechanisms:
one is the catalase-sensitive (H2O2-dependent) peroxidase-mediated oxidation of TMB, and the other the catalase-insensitive (H2O2-independent) oxidation of TMB, probably due to the oxidase activity of xylem peroxidases. The response of this TMB-oxidase
activity of xylem peroxidases to different exogenous H2O2 concentrations was studied, and the results showed that H2O2 at high concentrations (100–1,000 mM) clearly acted as an inactivator of this xylem TMB-oxidase activity, although some inhibitory
effect could still be appreciated at 10 mM H2O2. This xylem TMB-oxidase activity resided in a strongly basic cell wall-bound peroxidase (pl about 10.5). Given such a scenario,
it may be concluded that this TMB-oxidase activity of peroxidase is located in tissues capable of sustaining H2O2 production, and that the in situ oxidase activity shown by this enzyme is inactivated by high H2O2 concentrations.
Received 20 April 1999/ Accepted in revised form 16 August 1999 相似文献
10.
《Bioscience, biotechnology, and biochemistry》2013,77(4):928-934
We examined whether a difference in potassium dihydrogenphosphate (KH2PO4) and potassium tripolyphosphate (K5P3O10) as dietary phosphorus sources could differentially effect the nephrocalcinosis and proximal tubular function in female rats. Rats were fed on a diet containing KH2PO4 or K5P3O10, at the normal phosphorus level (normal phosphorus diet) or at a high phosphorus level (high-phosphorus diet) for 21 d. Nephrocalcinosis, as confirmed by a histological examination, was apparent in all rats fed on the high-phosphorus diet, and this condition was more severe in those rats fed on K5P3O10 than in those fed on KH2PO4. As indicators of the proximal tubular function, the N-acetyl-β-D-glucosaminidase activity in urine and the urinary β2-microglobulin excretion were significantly increased in those rats fed on the high-phosphorus diet containing K5P3O10. These results indicate that the intake of a high-phosphorus diet, more strongly influenced the nephrocalcinosis and proximal tubular function when K5P3O10 rather than KH2PO4 was used as the dietary phosphorus source. 相似文献
11.
S. Manara B. Palazzo E. Foresti S. Sabbatini G. Altankov 《Inorganica chimica acta》2008,361(6):1634-1645
A biomimetic bone-like composite, made of self-assembled collagen fibrils and carbonate hydroxyapatite nanocrystals, has been performed by an electrochemically-assisted deposition on titanium plate. The electrolytic processes have been carried out using a single type I collagen molecules suspension in a diluted Ca(NO3)2 and NH4H2PO4 solution at room temperature and applying a constant current for different periods of time. Using the same electrochemical conditions, carbonate hydroxyapatite nanocrystals or reconstituted collagen fibrils coatings were obtained. The reconstituted collagen fibrils, hydroxyapatite nanocrystals and collagen fibrils/apatite nanocrystals coatings have been characterized chemically, structurally and morphologically, as well as for their ability to bind fibronectin (FN). Fourier Transform Infrared microscopy has been used to map the topographic distribution of the coating components at different times of electrochemical deposition, allowing to single out the individual deposition steps. Moreover, roughness of Ti plate has been found to affect appreciably the nucleation region of the inorganic nanocrystals. Laser scanning confocal microscopy has been used to characterize the FN adsorption pattern on a synthetic biomimetic apatitic phase, which exhibits a higher affinity when it is inter-grown with the collagen fibrils. The results offer auspicious applications in the preparation of medical devices such as biomimetic bone-like composite-coated metallic implants. 相似文献
12.
Amal Hammami Ahmed Bayoudh Bilel Hadrich Ola Abdelhedi Mourad Jridi Moncef Nasri 《Biotechnology progress》2020,36(3):e2965
This work deals with the optimization of the culture conditions of Bacillus invictae AH1 in order to increase the production level of the proteolytic activity. Response-surface methodology (RSM) was applied for the most significant fermentation parameters (concentration of wheat bran and K2HPO4/KH2PO4) that were earlier identified by Plackett–Burman Design from seven possible factors. A central composite design was used and the quadratic regression model of producing active protease was built. A maximum protease activity was reached and validated experimentally, using a maximum wheat bran concentration (50 g/L) with increased K2HPO4/KH2PO4 concentration (2.275 g/L). Protease production obtained experimentally coincident with the predicted value and the model was proven to be adequate. Interestingly, the use of RSM increased the protease production by four times (7,000 U/mL) using a low-cost substrate and a culture time of 40 hr, as compared to the standard culture conditions. In the second part of this study, a H2O2-tolerant alkaline protease produced from B. invictae AH1 with a molecular mass of about 41 kDa, noted P3, was purified by successive steps of ultrafiltration, gel filtration and ion exchange chromatography. The K m and Vmax values of the purified protease using casein, as substrate, were about 4 mg/mL and 27 μM/min, respectively. The highest enzyme activity was found at pH 9.0 and a temperature of 60°C. In addition, the enzyme showed a quasi-total stability against H2O2 (5% for 1 hr) and against most of the tested solid and liquid detergents, suggesting its eventual use in bio-detergent formulations. 相似文献
13.
Rajan Singh Mohit Manhas Ankush Kumar Bedyal Fahim Durani Hendrick C. Swart Vinay Kumar 《Luminescence》2024,39(2):e4665
The present study investigates the impact of the ligand environment on the luminescence and thermometric behavior of Sm3+ doped A3(PO4)2 (A = Sr, Ca) phosphors prepared by combustion synthesis. The structural and luminescent properties of Sm3+ ions in the phosphate lattices were investigated using powder X-ray diffraction (PXRD) and photoluminescence (PL) techniques. PXRD results of the synthesized phosphors exhibit the expected phases that are in agreement with their respective standards. Fourier-transform infrared (FTIR) spectroscopy confirms the presence of PO4 vibrational bands. Upon excitation with near ultraviolet light, the PL studies indicated that Sr3(PO4)2:Sm3+ phosphors exhibit a yellow light emission, whereas Ca3(PO4)2:Sm3+ phosphors exhibit an emission of orange light. The PL emission results are in accordance with the CIE coordinates, with the Sr3(PO4)2:Sm3+ phosphors showing coordinates of (0.56, 0.44), and the Ca3(PO4)2:Sm3+ phosphors displaying coordinates of (0.60, 0.40). Thermal analysis shows improved stability of Ca3(PO4)2:Sm3+ based on lower weight reduction in thermogravimetric analysis. The effect of temperature on the luminescence properties of the phosphor has been examined upon a 405 nm excitation. By using the fluorescence intensity ratio (FIR) method, the temperature responses of the emission ratios from the Sm3+: the 4F3/2 → 6H5/2 transition to the 4G5/2 → 6H7/2 and 4F3/2 → 6H5/2 transition to the 4G5/2 → 6H9/2 emissions are characterized. The Ca3(PO4)2:Sm3+ phosphors are more sensitive as compared with the Sr3(PO4)2:Sm3+ phosphors. The earlier research findings strongly indicate that these phosphors hold great promise as ideal candidates for applications in non-invasive optical thermometry and solid-state lighting devices. 相似文献
14.
The bioprocess employing acyl transferase activity of intracellular amidase of Geobacillus pallidus BTP-5x MTCC 9225 was harnessed for the synthesis of pharmaceutically important acetohydroxamic acid. G. pallidus BTP-5x exhibited highest acyl transferase activity with acetamide: hydroxylamine in ratio of 1:5 in 0.1 M NaH2PO4/Na2HPO4 buffer (pH 7.5) at 65°C. In one liter fed-batch reaction containing 1:5 ratio of two substrates total of eight feedings of
0.05 M/20 min of acetamide were made and it was found that maximum acetohydroxamic production was achieved at 3:5 ratios of
substrate and cosubstrate. In 1 l bench scale batch reaction containing 0.3 M acetamide, 0.5 M hydroxylamine in 0.1 M NaH2PO4/Na2HPO4 buffer (pH 7.5, 50°C, 400 rpm) and 0.5 mg/ml (dry cell weight) of whole cells of G. pallidus BTP-5x (as biocatalyst) resulted in an yield of 0.28 M of acetohydroxamic acid after 20 min reaction time at 50°C. The acetamide
bioconversion rate was 90–95% (mol mol−1) and 51 g powder containing 40% (w/w) acetohydroxamic acid was recovered after lyophilization. 相似文献
15.
The development of fuel cells as clean-energy technologies is largely limited by the prohibitive cost of the noble-metal catalysts needed for catalyzing the oxygen reduction reaction (ORR) in fuel cells. A fundamental understanding of catalyst design principle that links material structures to the catalytic activity can accelerate the search for highly active and abundant bimetallic catalysts to replace platinum. Here, we present a first-principles study of ORR on Ag12Cu cluster in alkaline environment. The adsorptions of O2, OOH, and OH on Cu-doped Ag13 are stronger than on Ag13. The d-band centers of adsorption sites show the Cu-doping makes d-electrons transferred to higher energy state, and improves O2 dissociation. ORR processes on Ag12Cu and Ag13 indicate Cu-doping can strongly promote ORR, and ORR process can be better preformed on Ag12Cu than on Ag13. For four-electron transfer, the effective reversible potential is 0.401 V/RHE on Ag12Cu in alkaline medium. 相似文献
16.
Qing-Xiang Liu Hui-Long Li Xiao-Jun Zhao Shu-Sheng Ge Meng-Chao Shi Gang Shen Yan Zang Xiu-Guang Wang 《Inorganica chimica acta》2011,376(1):437-445
A series of NHC silver(I), mercury(II) and palladium(II) complexes, [(1,3-diethylbimy)6Ag4I3]I (2), [(1-benzyl-3-picolylbimy)Ag2Br2]n (3), [(1-benzyl-3-picolylbimy)HgI(CH2CN)]2 (4), {[(1-picolyl-3-npropylbimy)2Hg][Hg2I6]}n (5) and [(1,3-dipicolylbimy)PdCl]Cl (6), as well as one anionic complex [1,3-diethylbimidazolium]2[HgI4] (1) (bimy = benzimidazol-2-ylidene), have been prepared and characterized. Interestingly, a wind wheel-like Ag4I3 arrangement in 2 is formed, 1D polymeric chain containing 12-membered macrometallocycles and quadrangle Ag2Br2 units in 3 is generated, and the α-carbon atom of deprotonated acetonitrile ([CH2CN]−) in 4 participates in coordination with mercury(II) atom. In the crystal packings of complexes 1-6, 2D supramolecular layers or 3D supramolecular architectures are formed via intermolecular weak interactions, including π-π interactions, hydrogen bonds, C-H···π contacts, weak Hg···I bonds and I···I bonds. Additionally, the catalytic activity of the NHC palladium(II) complex 6 in Suzuki-Miyaura cross-coupling reaction was studied. 相似文献
17.
Extracellular alkaline phosphatase enzyme activity (APA) is important for algal phosphorus (P) acquisition in P‐limited freshwater ecosystems and is often used as an indicator of P deficiency. APA allows access to organic P (monophosphate esters), but the regulation of APA in response to availability of both PO43− and organic P is poorly characterized. This study aimed to examine the regulation of APA in freshwater Cladophora‐epiphyte assemblages in response to PO43− and a hydrolyzable organic P source, and for the first time to apply enzyme linked fluorescence (ELF) to localize APA within freshwater macroalgal‐epiphyte assemblages. In response to elevated PO43− concentrations, a component of net APA was suppressed, but there was also a constitutive APA, which was maintained even after prolonged exposure to nearly 1,000 μM PO43− and saturation of internal P pools. When supplied with organic glycerol P as the sole P source, the algae maintained APA in excess of needs for supplying PO43− for uptake, resulting in PO43− release into the medium. Constitutive APA may be adaptive to growth under chronic P limitation in oligotrophic freshwater habitats. Excess APA and release of PO43− could benefit different algal and bacterial partners within assemblages. APA in both Cladophora sp. and epiphytic algae was localized with ELF only when ethanol fixation was omitted. In algal subsamples exposed to different P treatments, there was no correlation between bulk APA (using 4‐methylumbelliferyl phosphate [MUP] substrate) and % cell labeling with ELF, suggesting that ELF labeling of APA was at best semiquantitative in the algal assemblages. 相似文献
18.
Enzyme preparations from pig heart and Escherichia coli have been found to catalyze a NAD+- and CoASH-dependent oxidation of 2-keto-4-hydroxyglutarate. Several independent lines of evidence indicate that 2-keto-4-hydroxyglutarate is a substrate for the well-known α-ketoglutarate dehydrogenase complex of the citric acid cycle. The evidence includes (a) a constant ratio of specific activity values for the two substrates throughout purification, (b) identical elution profiles from a Ca3(PO4)2 gel-cellulose column, (c) the same sucrose density sedimentation patterns, (d) similar responses in controlled heat inactivation studies, and (e) identical pH-activity curves. 相似文献
19.
The hydrothermal reactions of V2O5, a copper(II) source, 1,4-carboxy-phenylphosphonic acid, a bidentate organonitrogen ligand and HF provided a series of bimetallic organic-inorganic hybrid materials. [Cu(bpy)VO2(O2CC6H4PO3)] (1) is one-dimensional, while [Cu(bpa)VO(OH)(O2CC6H4PO3)] (2) and [Cu(phen)V2O4F(O2CC6H4PO3)] (3) are two-dimensional. In the absence of V2O5, a number of copper-organophosphonates were isolated. Compound 4 [Cu(phen)(H2O)(O2CC6H4PO3H)] is one-dimensional while [Cu3(bpy)2(O2CC6H4PO3)2] (5) is two-dimensional. Molecular structures were observed for [CuF(bpy)(H2O)(HO2CC6H4PO3H)] (6) and [Cu(bpa)(O2CC6H4PO3H)]·3H2O (7·3H2O). 相似文献
20.
Ce3+/Eu2+ co‐doped Na3Ca6(PO4)5 phosphors were prepared using a combustion‐assisted synthesis method. X‐Ray powder diffraction (XRD) analysis confirmed the formation of a Na3Ca6(PO4)5 crystal phase. Na3Ca6(PO4)5:Eu2+ phosphors have an efficient bluish‐green emission band that peaks at 489 nm, whereas Ce3+‐doped Na3Ca6(PO4)5 showed a bright emission band at 391 nm. Analysis of the experimental results suggests that enhancement of the Eu2+ emission intensity in co‐doped Na3Ca6(PO4)5:Eu2+,Ce3+ phosphors is due to a resonance‐type energy transfer from Ce3+ to Eu2+ ions, which is predominantly governed by an exchange interaction mechanism. These results indicate that Ce3+/Eu2+ co‐doped Na3Ca6(PO4)5 is potentially useful as a highly efficient, bluish‐green emitting, UV‐convertible phosphor for white‐light‐emitting diodes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献