scholarly journals Eu-Doped Zeolitic Imidazolate Framework-8 Modified Mixed-Crystal TiO2 for Efficient Removal of Basic Fuchsin from Effluent

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7265
Author(s):  
Wanqi Zhang ◽  
Hui Liu ◽  
Zhechen Liu ◽  
Yuhong An ◽  
Yuan Zhong ◽  
...  

Zeolitic imidazolate framework-8 (ZIF-8) was doped with a rare-earth metal, Eu, using a solvent synthesis method evenly on the surface of a mixed-crystal TiO2(Mc-TiO2) structure in order to produce a core–shell structure composite ZIF-8(Eu)@Mc-TiO2 adsorption photocatalyst with good adsorption and photocatalytic properties. The characterisation of ZIF-8(Eu)@Mc-TiO2 was performed via X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller analysis (BET) and ultraviolet–visible light differential reflectance spectroscopy (UV-DRs). The results indicated that Eu-doped ZIF-8 was formed evenly on the Mc-TiO2 surface, a core–shell structure formed and the light-response range was enhanced greatly. The ZIF-8(Eu)@Mc-TiO2 for basic fuchsin was investigated to validate its photocatalytic performance. The effect of the Eu doping amount, basic fuchsin concentration and photocatalyst dosage on the photocatalytic efficiency were investigated. The results revealed that, when 5%-Eu-doped ZIF-8(Eu)@Mc-TiO2 (20 mg) was combined with 30 mg/L basic fuchsin (100 mL) under UV irradiation for 1 h, the photocatalytic efficiency could reach 99%. Further, it exhibited a good recycling performance. Thus, it shows certain advantages in its degradation rate and repeatability compared with previously reported materials. All of these factors suggested that, in an aqueous medium, ZIF-8(Eu)@Mc-TiO2 is an eco-friendly, sustainable and efficient material for the photocatalytic degradation of basic fuchsin.

2013 ◽  
Vol 652-654 ◽  
pp. 683-686
Author(s):  
An Dong Yuan ◽  
Yue Lu Zhang ◽  
Wei Guang Yang ◽  
Ji Rong Li ◽  
Yang Liao ◽  
...  

ZnO@ZnS nano-array core-shell structure was synthesized through a solution method using a thioacetamide (TAA) solution in deionized water. The as-synthesized ZnO nano-array and TAA solution were employed to supply zinc and sulfur ions to form the ZnO@ZnS core-shell structures. The properties of the structure were characterized by X-ray diffraction (XRD), Raman spectrum, scanning electron microscopy (SEM) and UV-Vis spectra. The results indicate that ZnO nano-array was coated with ZnS particles. The concentration of TAA solution can affect the diameter, surface roughness and optical properties of the ZnO@ZnS nano-array core-shell structures.


2013 ◽  
Vol 320 ◽  
pp. 92-98 ◽  
Author(s):  
Dan Zhang ◽  
Guan Hua Gao ◽  
Wei Ma ◽  
Jian Yu Zhu ◽  
Guan Zhou Qiu ◽  
...  

Solvothermal synthesized monodisperse Fe3O4nanoparticles have been encapsulated with zinc sulfide shell through a simple ultrasonic-assisted aqueous-phase method under ambient environment. The monodisperse magnetic cores with average diameter of 180 nm were coated with zinc sulfide shelles (20~60 nm), in order to achieve a core-shell structure with both magnetic and luminescent properties. Structure, morphology and size of products were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The results display that the Fe3O4cores have been coated with ZnS shells Magnetic and optical properties of the nanocomposites were measured with vibrating sample magnetometer (VSM) and photoluminescence (PL) spectroscopy. Magnetic study reveals reduction of the saturation magnetization (Ms) for Fe3O4@ZnS nanocomposites compared with uncoated Fe3O4nanoparticles. Room temperature PL spectrum of the Fe3O4@ZnS samples shows two emission bands occurred at 389 and 292 nm, respectively. The bifunctional magentic-Optical materials can be used in biomedicine. Keywords: Fe3O4; ZnS; core-shell structure; nanocomposites


CrystEngComm ◽  
2020 ◽  
Vol 22 (30) ◽  
pp. 5031-5039
Author(s):  
Armin Hoell ◽  
Vikram Singh Raghuwanshi ◽  
Christian Bocker ◽  
Andreas Herrmann ◽  
Christian Rüssel ◽  
...  

Glasses with the mol% compositions 1.88 Na2O·15.04 K2O·7.52 Al2O3·69.56 SiO2·6.00 BaF2 and 1.88 Na2O·15.03 K2O·7.52 Al2O3·69.52 SiO2·6.00 BaF2·0.05 SmF3 were studied using X-ray diffraction, transmission electron microscopy, and anomalous small-angle X-ray scattering.


Author(s):  
Yaya Yuan ◽  
Yaqun Wang ◽  
Gui-lin Zhuang ◽  
Fenglei Yang ◽  
Qiu-Yan Li ◽  
...  

Improving the separation efficiency of photogenerated carriers and exposing more active sites are two important factors to improve photocatalytic efficiency of photocatalyst. Designing appropriate materials with special structure and composition...


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Chaoxia Zhao ◽  
Jie Yang ◽  
Yihan Wang ◽  
Bo Jiang

Well-dispersed nanoscale zero-valent iron (NZVI) supported inside the pores of macroporous silica foams (MOSF) composites (Mx-NZVI) has been prepared as the Cr(VI) adsorbent by simply impregnating the MOSF matrix with ferric chloride, followed by the chemical reduction with NaHB4 in aqueous solution at ambient atmosphere. Through the support of MOSF, the reactivity and stability of NZVI are greatly improved. Transmission electron microscopy (TEM) results show that NZVI particles are spatially well-dispersed with a typical core-shell structure and supported inside MOSF matrix. The N2 adsorption-desorption isotherms demonstrate that the Mx-NZVI composites can maintain the macroporous structure of MOSF and exhibit a considerable high surface area (503 m2·g−1). X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD) measurements confirm the core-shell structure of iron nanoparticles composed of a metallic Fe0 core and an Fe(II)/Fe(III) species shell. Batch experiments reveal that the removal efficiency of Cr(VI) can reach 100% when the solution contains 15.0 mg·L−1 of Cr(VI) at room temperature. In addition, the solution pH and the composites dosage can affect the removal efficiency of Cr(VI). The Langmuir isotherm is applicable to describe the removal process. The kinetic studies demonstrate that the removal of Cr(VI) is consistent with pseudo-second-order kinetic model.


2009 ◽  
Vol 79-82 ◽  
pp. 1643-1646 ◽  
Author(s):  
Qing Lin ◽  
Yan Bao Li ◽  
Xiang Hui Lan ◽  
Chun Hua Lu ◽  
Zhong Zi Xu

The amorphous calcium phosphate (ACP)/tricalcium silicate (Ca3SiO5, C3S) composite powders were synthesized in this paper. The exothermal behavior of C3S determined by isothermal conduction calorimetry indicated that the ACP could be synthesis by chemical precipitation method during the induction period (stage II) of C3S. The composite powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results indicated that nanosized ACP particles deposited on the surface of C3S particles to form core-shell structure at pH=10.5, and the nCa/nP of ACP could be controlled between 1.0 and 1.5. The core-shell structure is stable after sintered at 500 oC for 3 h to remove the β-cyclodextrin (β-CD). As compared with the irregular C3S particles (1~5 μm), the composite powders particles are spherical with a diameter of 40~150 μm. Therefore, to obtain the smaller size of composite powders, it is expected to avoid the aggregate of C3S particles in the aqueous solution by addition of dispersant. As compared with C3S, the composite powders may contribute better injectability, strength and biocompatibility.


2013 ◽  
Vol 834-836 ◽  
pp. 559-562 ◽  
Author(s):  
Juntima Pradid ◽  
Wirunya Keawwattana ◽  
Siree Tangbunsuk

An ultrasound field was applied to obtain Polylactic acid (PLA)/Hydroxyapatite (HAp) biocomposite microspheres with the specific core-shell structure to be applied as a carrier of a drug. The hydroxyapatite was obtained from crocodile bone by thermal process. Sample characterization was achieved by powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) Scanning electron microscopy (SEM) and High Performance Liquid Chromatography (HPLC). As the result, the PLA/HAp loading clindamycin with different polymer-to-ceramic part wt.% ratio (100:0, 90:10, 80:20, and 70:30) showed the agglomeration of sphere-like particles. In addition, the loading efficiency of clindamycin increased with increasing HAp content up to 20%.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Laura Angélica Ardila Rodriguez ◽  
Dilermando Nagle Travessa

The production of metal matrix composites with elevated mechanical properties depends largely on the reinforcing phase properties. Due to the poor oxidation resistance of multiwalled carbon nanotubes (MWCNTs) as well as their high reactivity with molten metal, the processing conditions for the production of MWCNT-reinforced metal matrix composites may be an obstacle to their successful use as reinforcement. Coating MWCNTs with a ceramic material that acts as a thermal protection would be an alternative to improve oxidation stability. In this work, MWCNTs previously functionalized were coated with titanium dioxide (TiO2) layers of different thicknesses, producing a core-shell structure. Heat treatments at three different temperatures (500°C, 750°C, and 1000°C) were performed on coated nanotubes in order to form a stable metal oxide structure. The MWCNT/TiO2 hybrids produced were evaluated in terms of thermal stability. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), and X-ray photoelectron spectroscopy (XPS) were performed in order to investigate TiO2-coated MWCNT structure and thermal stability under oxidative atmosphere. It was found that the thermal stability of the TiO2-coated MWCNTs was dependent of the TiO2 layer morphology that in turn depends on the heat treatment temperature.


2013 ◽  
Vol 750-752 ◽  
pp. 820-823
Author(s):  
Zhen Yu Liu ◽  
Yu Zhu Xiong ◽  
Wen Jie Mei ◽  
Li Wang

(POE-g-MAH/OMMT) and (POE-g-MAH/SiO2) toughening particles of core-shell structure were prepared by ball grinding method and were used to modify toughness of PA6.The morphology of PA6 modified by these core-shell particles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM),and were detected by mechanical performance test. The results show that both toughening particles could improved notch impact strength of PA6,and with toughening particle exceed 10%, composites notch impact strength is rapid increase.(POE-g-MAH/OMMT) particle of PA6 toughening effect is better than (POE-g-MAH/SiO2).When material under impact, OMMT produced slip effect in core-shell structure and SiO2 produced rolling effect.


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