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At least 1,783 records · Page 99
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Magnetic adsorbent constructed from the loading of amino functionalized Fe{sub 3}O{sub 4} on coordination complex modified polyoxometalates nanoparticle and its tetracycline adsorption removal property study

A magnetic polyoxometalates based adsorbent has been synthesized successfully through the loading of amino functionalized Fe{sub 3}O{sub 4} (NH{sub 2}-Fe{sub 3}O{sub 4}) on nanoparticle of a coordination complex modified polyoxometalates (CC/POMNP). FTIR illustrate there exist intense hydrogen bonds between NH{sub 2}-Fe{sub 3}O{sub 4} and CC/POMNP, which keep the stability of this adsorbent. At room temperature, this adsorbent exhibits ferromagnetic character with saturation magnetization of 8.19 emu g{sup −1}, which provides prerequisite for fast magnetic separation. Water treatment experiment illustrates this POM based magnetic adsorbent exhibits high adsorption capacity on tetracycline. The adsorption process can be described well with Temkin model, which illustrates the interaction between adsorbent and tetracycline plays the dominated role in tetracycline removal. The rapid, high efficient tetracycline adsorption ability suggests this POM based magnetic adsorbent exhibits promising prospect in medical and agriculture waste water purification. A magnetic polyoxometalates based adsorbent, which exhibits excellent tetracycline adsorption removal property has been synthesized through the loading of NH{sub 2}-Fe{sub 3}O{sub 4} on coordination complex modified polyoxometalates - Graphical abstract: A magnetic polyoxometalates based adsorbent, which exhibits excellent tetracycline adsorption removal property has been synthesized through the loading of NH{sub 2}-Fe{sub 3}O{sub 4} on coordination complex modified polyoxometalate. Display Omitted - Highlights: • A POM based magnetic adsorbent was fabricated through the loading of NH{sub 2}-Fe{sub 3}O{sub 4} on POM nanoparticle. • This adsorbent possesses excellent tetracycline adsorption property. • Saturation magnetization value of this adsorbent is 8.19 emug−1, which is enough for magnetic separation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Utilization of mixed ligands to construct diverse Ni(II)-coordination polymers based on terphenyl-2,2′,4,4′-tetracarboxylic acid and varied N-donor co-ligands

Three new coordination polymers, namely, {[Ni(H_2L)(bix)(H_2O)_2]·2h_2O}{sub n} (1), {[Ni(HL)(Hdpa)(H_2O)_2]·H_2O}{sub n} (2), {[Ni(L)_0_._5(bpp)(H_2O)]·H_2O}{sub n} (3) (H{sub 4}L=terphenyl-2,2′,4,4′-tetracarboxylic acid; bix=1,4-bis(imidazol-1-ylmethyl)benzene; dpa =4,4′-dipyridylamine; bpp=1,3-bis(4-pyridyl)propane), based on rigid H{sub 4}L ligand and different N-donor co-ligands, have been synthesized under hydrothermal conditions. Compound 1 features a 3D 4-connected 6{sup 6}-dia-type framework with H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two symmetry-related carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 0} monodentate mode. Compound 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, in which the H{sub 4}L ligand adopts a μ{sub 2}-bridging mode with two carboxylate groups in μ{sub 1}-η{sup 1}:η{sup 1} and μ{sub 1}-η{sup 1}:η{sup 0} monodentate modes, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology, with H{sub 4}L ligand displays a μ{sub 4}-bridging coordination mode. The H{sub 4}L ligand displays not only different deprotonated forms but also diverse coordination modes and conformations. The structural diversities among 1–3 have been carefully discussed, and the roles of N-donor co-ligands in the self-assembly of coordination polymers have been well documented. - Graphical abstract: Three nickel coordination polymers with different architectures based on mixed ligand system were synthesized and structurally characterized. Topology analyses indicate that 1 shows the 4-connected 6{sup 6}-dia net, 1D ribbon chains for 2 and 3D (4,4)-connected bbf network for 3. Display Omitted - Highlights: • Three Ni-based coordination polymers with distinct features have been prepared. • Compound 1 features a 3D 4-connected 66-dia-type framework, 2 displays a 1D [Ni(HL)(Hdpa)]{sub n} ribbon chains motif, while 3 possesses a (4,4)-connected 3D frameworks with bbf topology. • The “mixed ligand assembled” strategy is significant potential for network design.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Constructing MnO{sub 2}/single crystalline ZnO nanorod hybrids with enhanced photocatalytic and antibacterial activity

In order to improve the photocatalytic and antibacterial activity of ZnO nanorods, ZnO nanorods decorated with MnO{sub 2} nanoparticles (MnO{sub 2}/ZnO nanorod hybrids) were prepared by using microwave assisted coprecipitation method under the influence of hydrogen peroxide, and the structure, photocatalytic activity and antibacterial property of the products were studied. Experimental results indicated that MnO{sub 2} nanoparticles are decorated on the surface of single crystalline ZnO nanorods. Moreover, the resultant MnO{sub 2}/ZnO nanorod hybrids have been proven to possess good photocatalytic and antibacterial activity, which their degradated efficiency for Rhodamin B (RhB) is twice as the pure ZnO nanorods. Enhancement for photocatalytic and antibacterial activity is mainly attributed to the low band gap energy and excellent electrochemical properties of MnO{sub 2} nanoparticles. - Graphical abstract: The MnO{sub 2}/single crystalline ZnO nanorods hybrids, which MnO{sub 2} nanoparticles are loaded on the surface of ZnO nanorods, were prepared by the step-by-step precipitation method under the assistance of ammonia and hydrogen peroxide. Display Omitted - Highlights: • MnO{sub 2}/ZnO nanorod hybrids were prepared by the step-by-step assembly method. • Single crystalline ZnO nanorods can be decorated by MnO{sub 2} nanoparticles. • MnO{sub 2}/ZnO nanorod hybrids possess good photocatalytic and antibacterial activity. • MnO{sub 2} can improve the photocatalytic activity of ZnO nanorods under visible light.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Construction of three lanthanide metal-organic frameworks: Synthesis, structure, magnetic properties and highly selective sensing of metal ions

Three lanthanide metal-organic frameworks (Ln-MOFs), [Ln(TZI)(H{sub 2}O){sub 4}]·3H{sub 2}O (Ln=Gd (1) and Tb (2) and Dy (3), H{sub 3}TZI=5-(1H-tetrazol-5-yl)isophthalic acid), have been synthesized under hydrothermal conditions. Single crystal X-ray diffraction reveals that 1–3 are isostructural and display a 1D double chain based on dinuclear motifs with (μ-COO){sub 2} double bridges. Magnetic studies indicate antiferromagnetic interactions in 1, ferromagnetic interactions in 2 and 3. Furthermore, compound 3 displays a slow relaxation behavior. Compound 2 exhibits intense characteristic green emission of Tb(III) ions in the solid state, which can be observed by the naked eye under UV light. Interestingly, 2 can selectively sense Pb{sup 2+} and Fe{sup 3+} ions through luminescence enhancement and quenching, respectively. The luminescence quenching mechanisms have been investigated in detail. The study on luminescence Ln-MOFs as a probe for sensing Pb{sup 2+} and Fe{sup 3+} ions is exceedingly rare example. - Graphical abstract: Three Ln-MOFs were successfully synthesized using a 5-(1H-tetrazol-5-yl)isophthalic acid ligand. They displays different magnetic behavior. Especially, the Dy(III) compound slow relaxation behavior. Interestingly, the Tb(III) compound can selectively sense Pb{sup 2+} and Fe{sup 3+} ions through luminescence enhancement and quenching, respectively. - Highlights: • Three Ln-MOFs with tetrazolate dicarboxylate ligand. • Dy(III) compound displays slow relaxation behavior. • The Tb(III) compound shows highly selective luminescence sensing of the Fe{sup 3+} and Pb{sup 2+} ions.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Coordination Architectures of energetic Cd (II) coordination polymers constructed by the bifunctional substituted-tetrazole-carboxylate ligands

Three different tetrazole-carboxylate ligands, monotetrazole-carboxylate H{sub 2}tza (H{sub 2}tza=1,5-tetrazole-diacetic acid), Hpztza (Hpztza=5-(2-pyrazinyl)tetrazole-2(1-methyl)acetic acid), ditetrazole-carboxylate H{sub 2}tzpha (H{sub 2}tzpha=1,3-di(tetrazole-5-yl)benzene-N2,N2′-diacetic acid) have been chosen to react with CdCl{sub 2}·6H{sub 2}O, resulting in the formation of three new compounds [Cd{sub 2}(tza){sub 2}] (1), [Cd(pztza){sub 2}] (2) and [Cd(tzpha)(CH{sub 3}OH){sub 2}] (3). The coordinate sites of the three ligands are major influenced by the different substituted group of tetrazole ring. These compounds have been characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 displays a complex 3D structure; compound 2 shows a 3D network and compound 3 features a 2D layer network. Furthermore, the luminescence properties investigated at room temperature in the solid state showed excellent ligand-centered luminescence. The obvious enhancement in luminescence makes these compounds potential materials for optical use. The differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG) analyses were applied to evaluate the thermal decomposition behavior of such compounds, showing that compounds 2 and 3 can be used as potential energetic materials. The relevant thermodynamic parameters ΔH, ΔS and ΔG were calculated as well. - Graphical abstract: H{sub 2}tza, Hpztza and H{sub 2}tzpha have been prepared. Three novel Cd (II)compounds were synthesized by reactions of CdCl{sub 2}·6H{sub 2}O, namely three dimensional [Cd{sub 2}(tza){sub 2}] (1), three dimensional [Cd(pztza){sub 2}] (2), and two dimensional [Cd(tzpha)(CH{sub 3}O){sub 2}] (3). The luminescences were investigated. Furthermore, the DSC show compounds 1 and 3 can be used as potential explosive materials.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Copper coordination polymers constructed from thiazole-5-carboxylic acid: Synthesis, crystal structures, and structural transformation

We have successfully prepared crystals of thiazole-5-carboxylic acid (5-Htza) (L) and three new thiazole-5-carboxylate-based Cu{sup 2+} coordination polymers with different dimensionality, namely, 1D [Cu{sub 2}(5-tza){sub 2}(1,10-phenanthroline){sub 2}(NO{sub 3}){sub 2}] (1), 2D [Cu(5-tza){sub 2}(MeOH){sub 2}] (2), and 3D [Cu(5-tza){sub 2}]·H{sub 2}O (3). These have been characterized by single crystal X-ray diffraction and thermogravimetry. Interestingly, the 2D network structure of 2 can directly transform into the 3D framework of 3 upon removal of methanol molecules at room temperature. 2 can also undergo structural transformation to produce the same 2D network present in the known [Cu(5-tza){sub 2}]·1.5H{sub 2}O upon heat treatment for 2 h. This 2D network can adsorb water and convert to 3 upon exposure to air. - Highlights: • Rare examples of coordination polymers of thiazole-5-carboxylic acid were prepared. • Non-covalent interactions play a key role on the assembly of the complexes in solid state. • Structural transformation of a 2D framework to a 3D upon removal of methanol is observed.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Design and construction of diverse structures of coordination polymers: Photocatalytic properties

The reaction of Cu(NO{sub 3}){sub 2}·3H{sub 2}O/Ni(NO{sub 3}){sub 2}·6H{sub 2}O with 4′-(4-(3,5-dicarboxylphenoxy)phenyl)-4,2′:6′,4′′-terpyridine (H{sub 2}dbp) gave [Cu{sub 0.5}(Hdbp)]{sub n} (1) and [Ni(dbp)(H{sub 2}O)]{sub n} (2), while the reactions of Co(NO{sub 3}){sub 2}·6H{sub 2}O with H{sub 2}dbp in the presence of 4,4′-bipy and 2,2′-bpy generated [Co(dbp)(4,4′-bipy)]{sub n} (3) and ([Co(dbp)(2,2′-bipy)]{sub n}·H{sub 2}O) (4), respectively (4,4′-bipy=4.4′-pyridine and 2,2′-bipy=2,2′-bipyridine). X-Ray single-crystal analyses reveal that 1 contains a 1D double chain. 2 possesses a 3D architecture with (4.6{sup 2}0.8{sup 3}){sub 2} topology that is interpenetrated with each other to form a 2-fold network. In 3, the 2D [Co(dbp)]n sheets are pillared by 4,4′-bpy to form a 3D framework with 1D open channel. Compound 4 consists of a 1D ladder-like chain. The results showed that the structural diversity of the coordination polymers resulted from the different geometries of metal ions and effect of assistant ligands. Furthermore, the photocatalytic properties of 1–4 for degradation of the methyl violet (MV) have been examined. - Graphical abstract: The photocatalytic activity and selectivity of complexes 1–4 prove that they may be good and stable photocatalysts for degradation of organic dyes.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Construction of hierarchical porous NiCo{sub 2}O{sub 4} films composed of nanowalls as cathode materials for high-performance supercapacitor

Graphical abstract: Hydrothermal-synthesized NiCo{sub 2}O{sub 4} mesowall films exhibit porous structure and high capacity as well as good cycling life for supercapacitor application. - Highlights: • Hierarchical porous NiCo{sub 2}O{sub 4} nanowall films are prepared by a hydrothermal method. • NiCo{sub 2}O{sub 4} nanowall films show excellent electrochemical performance. • Hierarchical porous film structure is favorable for fast ion/electron transfer. - Abstract: Hierarchical porous NiCo{sub 2}O{sub 4} films composed of nanowalls on nickel foam are synthesized via a facile hydrothermal method. Besides the mesoporous walls, the NiCo{sub 2}O{sub 4} nanowalls are interconnected with each other to form hierarchical porous structure. These unique porous structured films possess a high specific surface area. The supercapacitor performance of the hierarchical porous NiCo{sub 2}O{sub 4} film is fully characterized. A high capacity of 130 mA h g{sup −1} is achieved at 2 A g{sup −1} with 97% capacity maintained after 2,000 cycles. Importantly, 75.6% of capacity is retained when the current density changes from 3 A g{sup −1} to 36 A g{sup −1}. The superior electrochemical performance is mainly due to the unique hierarchical porous structure with large surface area as well as shorter diffusion length for ion and charge transport.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Construction of CQDs-Bi{sub 20}TiO{sub 32}/PAN electrospun fiber membranes and their photocatalytic activity for isoproturon degradation under visible light

Highlights: • The flexible fiber membranes were prepared by coaxial electrospinning technique. • CQDs-Bi{sub 20}TiO{sub 32} photocatalyst was uniformly fixed on the surfaces of PAN fibers. • The fiber membranes had high photocatalytic activity for degradation of isoproturon. • The composite fiber membranes exhibited good recyclability. - Abstract: The CQDs-Bi{sub 20}TiO{sub 32} photocatalysts exhibited high visible-light responsive photocatalytic activity. To achieve the cyclic utilization of CQDs-Bi{sub 20}TiO{sub 32}, the novel flexible CQDs-Bi{sub 20}TiO{sub 32}/PAN fiber membranes were prepared by a simple coaxial electrospinning technique. It was found that the CQDs-Bi{sub 20}TiO{sub 32} photocatalyst could be firmly and uniformly fixed on the surfaces of electrospun fibers and the composite fiber membranes possessed the hierarchical macro- and mesoporous structure. The loaded CQDs-Bi{sub 20}TiO{sub 32} endowed the composite fiber with an obvious photocatalytic activity for the degradation of the herbicide isoproturon under visible light irradiation. Among these samples, S3 at photocatalyst dosage 15 w/v% had the highest degradation efficiency for isoproturon. Meanwhile, the core-shell structured inorganic-organic hybrid fiber membranes have a significant advantage in the recyclability for photocatalyts. The flexible CQDs-Bi{sub 20}TiO{sub 32}/PAN electrospun fiber membranes would have potential applications in efficient removal of organic contaminants.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Remarkable enhancement of photocatalytic performance via constructing a novel Z-scheme KNbO{sub 3}/Bi{sub 2}O{sub 3} hybrid material

Highlights: • A series of KNbO{sub 3}/Bi{sub 2}O{sub 3} composite materials with different percentage of KNbO{sub 3} have been prepared by simple methods using Bismuth oxide, niobium pentoxide and potassium hydroxide as precursors. • The rate constants of the best photocatalyst (30 wt.% KNbO{sub 3}/Bi{sub 2}O{sub 3}) for the RhB and MO degradation are about 3.7 times and 4.1 times faster than those of pure Bi{sub 2}O{sub 3} and approximately 6.9 times and 7.1 times faster than those of pure KNbO{sub 3}, respectively. • The composite photocatalyst exhibits a good physical and chemical stability during the photocatalytic reaction process. • Results demonstrat that the migration of photogenerated carriers adopts a direct Z-scheme mechanism and ·O{sup 2−}, ·OH, and h{sup +} are the main reactive species in the photocatalytic process. - Abstract: KNbO{sub 3}/Bi{sub 2}O{sub 3} composite materials with different percentage of KNbO{sub 3} have been prepared by simple methods The structural and optical properties of the resulting samples are thoroughly characterized by XRD, UV–vis DRS, SEM, TEM, and N{sub 2}-sorption analysis. The photocatalytic activities of the as-prepared materials for the degradation of rhodamine B (RhB) and methyl orange (MO) are evaluated under UV-light irradiation. The results indicate that the optimal loading amount of KNbO{sub 3} is 30 wt.% (i. e., 30 wt.% KNbO{sub 3}/Bi{sub 2}O{sub 3}), The rate constants of which for the RhB and MO degradation are about 3.7 times and 4.1 times faster than those of pure Bi{sub 2}O{sub 3} and approximately 6.9 times and 7.1 times faster than those of pure KNbO{sub 3}, respectively. Based on a series of characterizations, it can be concluded that the migration of photogenerated carriers adopts a direct Z-scheme mechanism and ·O{sup 2−}, ·OH, and h{sup +} are the main reactive species in the photocatalytic reactions.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Construction of hybrid Ag2CO3/AgVO3 nanowires with enhanced visible light photocatalytic activity

Highlights: • Hybrid Ag{sub 2}CO{sub 3}/AgVO{sub 3} nanowires were successfully synthesized. • The as-prepared sample displayed highly enhanced photocatalytic activity. • Possible photocatalytic mechanism for RhB degradation was proposed. - Abstract: Visible light driven pollutant degradation by photocatalyst was one of most efficient and economical strategies for environmental application. The focus and challenge was to fabricate efficient artificial photocatalysts. In this work, hybrid Ag{sub 2}CO{sub 3}/AgVO{sub 3} nanowires were first reported to be successfully synthesized by the facile ion-exchange method. The as-prepared Ag{sub 2}CO{sub 3}/AgVO{sub 3} nanowires showed highly improved visible light photocatalytic activity for RhB degradation, and the optimized Ag{sub 2}CO{sub 3}/AgVO{sub 3}-40% photocatalyst exhibited the best photocatalytic activity, which is 3.6 times of pure Ag{sub 2}CO{sub 3} and 13.3 times of pure AgVO{sub 3} catalysts, mainly due to the formation of Ag nanoparticles and Ag{sub 2}CO{sub 3}/AgVO{sub 3} heterojunction for charge separation. The degradation of RhB solution was mainly attributed to direct hole oxidation, which was also confirmed by the active species trapping experiments. Finally, the possible visible light photocatalytic mechanism of Ag/Ag{sub 2}CO{sub 3}/AgVO{sub 3} composites for RhB degradation was proposed.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2018

A construction of Ag-modified raspberry-like AgCl/Ag2WO4 with excellent visible-light photocatalytic property and stability

Highlights: • The Ag-modified raspberry-like AgCl/Ag{sub 2}WO{sub 4} photocatalysts were prepared by a facile solvent-free method. • Ag and AgCl were easily deposited on the Ag{sub 2}WO{sub 4} by one-step solid-sate reaction between Ag{sub 2}WO{sub 4} and HONH{sub 3}Cl. • The morphology of raspberry-like can facilitate the contact of dye molecules and composite photocatalysts. • The photocatalysts exhibit an effective separation of the photoinduced electron-hole pairs. • The photocatalysts show excellent photocatalytic activity and photo-stability under visible light irradiation. - Abstract: A novel multiphase photocatalyst of Ag-modified raspberry-like AgCl/Ag{sub 2}WO{sub 4} composite was successfully fabricated via a facile solvent-free reaction technique, in which the Ag and AgCl were subtlely generated from the one-step reaction between Ag{sub 2}WO{sub 4} particles and HONH{sub 3}Cl as reductant and chlorine source at room temperature. The as-obtained ternary Ag-modified raspberry-like AgCl/Ag{sub 2}WO{sub 4} composites can facilitate the contact of dye molecules and photocatalysts, exhibiting superior photocatalytic property and good recycling ability towards the decomposition of organic dye under the visible-light irradiation. The reductant addition amounts greatly affect the performance of Ag{sub 2}WO{sub 4} photocatalyst. The optimum composite ratio of Ag-modified AgCl/Ag{sub 2}WO{sub 4} samples show significant enhancement of visible-light photocatalytic activities and the degradation rate constant is about 16 times greater than that of pure Ag{sub 2}WO{sub 4}. The highly improved performance of Ag-modified raspberry-like AgCl/Ag{sub 2}WO{sub 4} structure can be ascribed to the surface plasma resonance (SPR) effects of metal Ag and the synergistic effect among composites, accordingly effectively promote the separation of photoinduced electron-hole pairs, widen the absorbance range in the visible light and increase surface area. The h{sup +} and ·OH degraded mechanism for the improved photocatalytic activity of Ag-modified AgCl/Ag{sub 2}WO{sub 4} is proposed based on radical-trapping experiments and ESR spectra records.

36 MATERIALS SCIENCE↗
DOE OSTI2018

In situ construction of conjugated polymer P3HT coupled hierarchical ZnO composite with Z-scheme enhanced visible-light photocatalytic activity

Highlights: • P3HT@H-ZnO photocatalysts were fabricated via a two-step solution method. • The P3HT@H-ZnO composite. exhibited high photodegredation of RhB under visible-light. • Enhanced photocatalytic activity attributed to the closely contacted interface between P3HT and H-ZnO and the matched band gap structure. • The fabricated P3HT@H-ZnO composite follow a Z-scheme mechanism rather than type II heterojunction. - Abstract: Conjugated polymer P3HT coupled with hierarchical ZnO (H-ZnO) photocatalysts were fabricated by a two-step solution method with assembling P3HT nanoparticles on the surface of H-ZnO micro-flowers. Optical properties revealed that the fabricated H-ZnO micro-flowers were rich in defects. The as-prepared P3HT@H-ZnO composite exhibited higher photocatalytic activity than H-ZnO for photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The enhanced photocatalytic activity was attributed to the strengthened visible light absorption and the closely contacted interface between P3HT and H-ZnO. Based on the reactive species trapping experiments and band gap structure analysis, it can be identified that the effective separation and transfer of the photo-induced electron-hole pairs within the P3HT@H-ZnO composite follow a Z-scheme mechanism rather than type II heterojunction. The present work will provide a new insight to design Z-scheme photocatalysts with enhanced photocatalytic performance via metal-free polymers modification.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

Construction of Eu2+ doped H3Sr6(PO4)5·2H2O with novel cruciate multilayer microarchitectures: facile hydrothermal synthesis, growth mechanism, and luminescence properties

Highlights: • H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:Eu{sup 2+} phosphors were synthesized via a simple hydrothermal method. • H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:Eu{sup 2+} showed novel cruciate multilayer microarchitectures. • Phase and morphology were depended on the optimization of the reaction conditions. • H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:Eu{sup 2+} exhibited intense characteristic blue emission of Eu{sup 2+}. - Abstract: A series of monodisperse cruciate multilayer H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:Eu{sup 2+} microarchitectures assembled by crossed nanorods have been successfully synthesized via a facile surfactant-assisted hydrothermal route. XRD and FT-IR confirmed the existence of crystalline water in the phosphor. The FE-SEM images revealed that the phase and morphology of resulting samples were strongly depended on the optimization of the reaction conditions, especially the pH value and the molar ratio of citric acid (CA)/Cations. Furthermore, the possible growth mechanism of H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:Eu{sup 2+} microarchitectures was proposed in detail. Under near-ultraviolet excitation of 365 nm, the as-obtained H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:0.05Eu{sup 2+} sample exhibited intense wide characteristic blue emission of Eu{sup 2+}, which could be decomposed by Gaussian fitting into two peaks corresponding to different Eu{sup 2+} luminous centers. The present results demonstrated that the morphology-tunable H{sub 3}Sr{sub 6}(PO{sub 4}){sub 5}·2H{sub 2}O:Eu{sup 2+} microarchitecture could be used as a potential candidate for future optoelectronic device applications.

77 NANOSCIENCE AND NANOTECHNOLOGY↗