Controlling the Wall Thickness and Pore Size of SBA-15 by Using PPG and PEG as Additives

Ordered mesoporous silica SBA-15 with controlled pore size and wall thickness was synthesized using polypropylene glycol (PPG) and polyethylene glycol (PEG) as different additives. The final samples were characterized by low-angle X-ray diffraction, N2 adsorption-desorption and transmission electron microscopy. The SBA-15 used PPG or PEG as additive all could maintain the two-dimensional hexagonal structure. The addition of PPG could expand the pore size and decrease the wall thickness and the addition of PEG could reduce the pore size and increase the wall thickness of SBA-15.

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Immobilization of hemoglobin on stable mesoporous multilamellar silica vesicles and their activity and stability

Journal of Materials Research ◽

10.1557/jmr.2005.0360 ◽

2005 ◽

Vol 20 (10) ◽

pp. 2682-2690 ◽

Cited By ~ 15

Author(s):

Yufang Zhu ◽

Weihua Shen ◽

Xiaoping Dong ◽

Jianlin Shi

Keyword(s):

Thermal Stability ◽

Pore Size ◽

X Ray Diffraction ◽

X Ray ◽

Practical Applications ◽

Silica Material ◽

Transmission Electron ◽

Mesoporous Support ◽

Adsorption Desorption ◽

Thermal Stability Of

A stable mesoporous multilamellar silica vesicle (MSV) was developed with a gallery pore size of about 14.0 nm. A simulative enzyme, hemoglobin (Hb), was immobilized on this newly developed MSV and a conventional mesoporous silica material SBA-15. The structures and the immobilization of Hb on the mesoporous supports were characterized with x-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier transform infrared, ultraviolet-visible spectroscopy, and so forth. MSV is a promising support for immobilizing Hb due to its large pore size and high Hb immobilization capacity (up to 522 mg/g) compared to SBA-15 (236 mg/g). Less than 5% Hb was leached from Hb/MSV at pH 6.0. The activity study indicated that the immobilized Hb retained most peroxidase activity compared to free Hb. Thermal stability of the immobilized Hb was improved by the proctetive environment of MSV and SBA-15. Such an Hb-mesoporous support with high Hb immobilization capacity, high activity, and enhanced thermal stability will be attractive for practical applications.

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Ordered Mesoporous SBA-15 for Controlled Release of Water-Insolube Drug

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.1873 ◽

2011 ◽

Vol 236-238 ◽

pp. 1873-1876 ◽

Cited By ~ 4

Author(s):

Jun Jie Tao ◽

Yun Qiang Xu ◽

Guo Wei Zhou ◽

Cui Cui Wu ◽

Hong Bin Song ◽

...

Keyword(s):

Electron Microscopy ◽

Controlled Release ◽

Hydrothermal Process ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Mesoscopic Structure ◽

Ordered Mesoporous ◽

Adsorption Desorption ◽

Phosphate Buffered Saline

Ordered mesoporous SBA-15 was synthesized through hydrothermal process under acidic condition. The material was characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), small-angle X-ray diffraction (SAXRD), and N2 adsorption-desorption. The results indicated that SBA-15 has 2-dimensional hexagonal p6mm mesoscopic structure and well-ordered parallel mesochannel. The as-obtained mesoporous silica was used for controlled release of water-insolube drug emodin. The loading capacity could achieve 6.64 mg/g, and the release profiles that studied in phosphate buffered saline (PBS, pH = 7.4) showed that released amount of emodin was 95.8 % after 48 h.

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Positron Annihilation Study of Porous ZnO Synthesized with Soft Template

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.373.299 ◽

2017 ◽

Vol 373 ◽

pp. 299-302

Author(s):

Bo Zhou ◽

Chong Yang Li ◽

Ning Qi ◽

Zhi Quan Chen

Keyword(s):

Pore Size ◽

Positron Lifetime ◽

Nitrogen Adsorption ◽

Soft Template ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Long Lifetime ◽

Positron Annihilation Study ◽

Adsorption Desorption

Porous ZnO were synthesized with soft template method using zinc acetate Zn (CH3COO)2·2H2O as precursor and block copolymer F127 as the surfactant. Nitrogen adsorption-desorption measurements indicate that the ZnO sample contains large pores with mean diameter of about 30 nm. However, both small-angle X-ray diffraction and transmission electron microscope measurements indicate that the pore ordering is missing. Positron lifetime measurements reveal two long lifetime components in the porous ZnO. The longest lifetime τ4 (75 ns) corresponds to ortho-positronium (o-Ps) annihilation in large pores. The pore size estimated from τ4 is about 10.6 nm. This is much smaller than that estimated from Nitrogen adsorption-desorption measurements. In addition, the intensity I4 is only about 2.2%. This is probably due to the chemical quenching and/or inhibition of positronium formation induced by ZnO, which reduces o-Ps lifetime and intensity, and leads to under estimation of the pore size.

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Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.1511 ◽

2012 ◽

Vol 512-515 ◽

pp. 1511-1515

Author(s):

Chun Lin Zhao ◽

Li Xing ◽

Xiao Hong Liang ◽

Jun Hui Xiang ◽

Fu Shi Zhang ◽

...

Keyword(s):

Room Temperature ◽

Hexagonal Structure ◽

Diffraction Measurement ◽

X Ray Diffraction ◽

Visible Absorption ◽

X Ray ◽

Cds Nanocrystals ◽

Morphological Studies ◽

Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

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Behaviours of direct yellow 12 adsorption on mesoporous carbons with different pore geometries

Water Science & Technology ◽

10.2166/wst.2018.104 ◽

2018 ◽

Vol 2017 (1) ◽

pp. 219-228

Author(s):

Fengling Liu ◽

Ziyan Guo ◽

Hui Qiu ◽

Xia Lu ◽

Hua Fang ◽

...

Keyword(s):

Mesoporous Carbons ◽

X Ray Diffraction ◽

Pore Characteristics ◽

X Ray ◽

Transmission Electron ◽

Cylindrical Pores ◽

Pseudo Second Order ◽

Hexagonally Ordered ◽

Adsorption Desorption ◽

Interconnected Pore

Abstract Four kinds of mesoporous carbons, C1-h-w, C2-h-h, C3-s-w, and C4-s-h, with different pore geometries were prepared and characterised, and their adsorption behaviours with aqueous direct yellow 12 (DY-12) were investigated. The results of X-ray diffraction and transmission electron microscopy show that C1-h-w and C3-s-w have wormlike pore characteristics, whereas C2-h-h and C4-s-h have 2-D hexagonally arranged pores. According to the N2 adsorption/desorption results, the specific surface area of C1-h-w (1,378 m2/g) is the largest among the four carbons. The adsorption isotherms could be effectively fitted using the Langmuir model. The maximum adsorption amounts of C1-h-w, C2-h-h, C3-s-w and C4-s-h are 0.968 mmol/g, 0.726 mmol/g, 0.161 mmol/g and 0.156 mmol/g, respectively. The pseudo-second-order rate constants of C1-h-w (39.8 g/(mmol·min)) and C2-h-h (7.28 g/(mmol·min)) are substantially larger than those of C3-s-w (0.0046 g/(mmol·min)) and C4-s-h (0.014 g/(mmol·min)), indicating that an open and interconnected pore geometry is favourable for DY-12 adsorption. Furthermore, DY-12 diffusion in 2-D hexagonally ordered cylindrical pores is superior to that in wormlike pores due to the smoothness of the channels in the former. External mass transfer and intraparticle diffusion both play roles in the adsorption process.

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Formation and Thermal Stability of Nd0.32Y0.68Si1.7 Layers Formed by Channeled Ion Beam Synthesis

MRS Proceedings ◽

10.1557/proc-514-191 ◽

1998 ◽

Vol 514 ◽

Cited By ~ 1

Author(s):

M. F. Wu ◽

A. Vantomne ◽

S. Hogg ◽

H. Pattyn ◽

G. Langouche ◽

...

Keyword(s):

Thermal Stability ◽

Ion Beam ◽

Hexagonal Structure ◽

Orthorhombic Structure ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Good Crystalline Quality ◽

Ion Beam Synthesis ◽

Thermal Stability Of

ABSTRACTThe Nd-disilicide, which exists only in a tetragonal or an orthorhombic structure, cannot be grown epitaxially on a Si(111) substrate. However, by adding Y and using channeled ion beam synthesis, hexagonal Nd0.32Y0.68Si1.7 epilayers with lattice constant of aepi = 0.3915 nm and cepi = 0.4152 nm and with good crystalline quality (χmin of Nd and Y is 3.5% and 4.3 % respectively) are formed in a Si(111) substrate. This shows that the addition of Y to the Nd-Si system forces the latter into a hexagonal structure. The epilayer is stable up to 950 °C; annealing at 1000 °C results in partial transformation into other phases. The formation, the structure and the thermal stability of this ternary silicide have been studied using Rutherford backscattering/channeling, x-ray diffraction and transmission electron microscopy.

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FeYO3@rGO nanocomposites: Synthesis, characterization and application in photooxidative degradation of atrazine under visible light

Materials Express ◽

10.1166/mex.2021.1957 ◽

2021 ◽

Vol 11 (5) ◽

pp. 706-716

Author(s):

Nada D. Al-Khthami ◽

Tariq Altalhi ◽

Mohammed Alsawat ◽

Mohamed S. Amin ◽

Yousef G. Alghamdi ◽

...

Keyword(s):

Visible Light ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Bandgap Energy ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Reduced Graphene ◽

Structural Surface ◽

Adsorption Desorption

Different organic pollutants have been remediated photo catalytically by applying perovskite photocatalysts. Atrazine (ATR) is a pesticide commonly detected as a pollutant in drinking, surface and ground water. Herein, FeYO3@rGO heterojunction was synthesized and applied for photooxidation decomposition of ATR. First, FeYO 3nanoparticles (NPs) were prepared via routine sol-gel. After that, FeYO3 NPs were successfully incorporated with different percentages (5, 10, 15 and 20 wt.%) of reduced graphene oxide (rGO) in the synthesis of novel FeYO3@rGO photocatalyst. Morphological, structural, surface, optoelectrical and optical characteristics of constructed materials were identified via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), adsorption/desorption isotherms, diffusive reflectance (DR) spectra, and photoluminescence response (PL). Furthermore, photocatalytic achievement of the constructed materials was evaluated via photooxidative degradation of ATR. Various investigations affirmed the usefulness of rGO incorporation on the advancement of formed photocatalysts. Actually, novel nanocomposite containing rGO (15 wt.%) possessed diminished bandgap energy, as well as magnified visible light absorption. Furthermore, such nanocomposite presented exceptional photocatalytic achievement when exposed to visible light as ATR was perfectly photooxidized over finite amount (1.6 g · L-1) from the optimized photocatalyst when illuminated for 30 min. The advanced photocatalytic performance of constructed heterojunctions could be accredited mainly to depressed recombination amid induced charges. The constructed FeYO3@rGO nanocomposite is labelled as efficient photocatalyst for remediation of herbicides from aquatic environments.

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Preparation, Characterization, and Performance Analysis of S-Doped Bi2MoO6 Nanosheets

Nanomaterials ◽

10.3390/nano9091341 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1341 ◽

Cited By ~ 1

Author(s):

Ruiqi Wang ◽

Duanyang Li ◽

Hailong Wang ◽

Chenglun Liu ◽

Longjun Xu

Keyword(s):

Photoelectron Spectroscopy ◽

Degradation Rate ◽

X Ray Diffraction ◽

Photo Degradation ◽

X Ray ◽

Transmission Electron ◽

Ft Ir ◽

And Performance ◽

Adsorption Desorption ◽

Excellent Stability

S-doped Bi2MoO6 nanosheets were successfully synthesized by a simple hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), elemental mapping spectroscopy, photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and UV-visible diffused reflectance spectra (UV-vis DRS). The photo-electrochemical performance of the samples was investigated via an electrochemical workstation. The S-doped Bi2MoO6 nanosheets exhibited enhanced photocatalytic activity under visible light irradiation. The photo-degradation rate of Rhodamine B (RhB) by S-doped Bi2MoO6 (1 wt%) reached 97% after 60 min, which was higher than that of the pure Bi2MoO6 and other S-doped products. The degradation rate of the recovered S-doped Bi2MoO6 (1 wt%) was still nearly 90% in the third cycle, indicating an excellent stability of the catalyst. The radical-capture experiments confirmed that superoxide radicals (·O2−) and holes (h+) were the main active substances in the photocatalytic degradation of RhB by S-doped Bi2MoO6.

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ZnFe2O4-TiO2Nanoparticles within Mesoporous MCM-41

The Scientific World JOURNAL ◽

10.1100/2012/480527 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Aidong Tang ◽

Yuehua Deng ◽

Jiao Jin ◽

Huaming Yang

Keyword(s):

Sol Gel ◽

Rutile Phase ◽

Band Gap Energy ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Agglomeration Of Nanoparticles ◽

Adsorption Desorption ◽

Mcm 41

A novel nanocomposite ZnFe2O4-TiO2/MCM-41 (ZTM) was synthesized by a sol-gel method and characterized through X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), N2adsorption-desorption, Raman spectroscopy, and ultraviolet visible (UV-vis) spectrophotometry. The results confirmed the incorporation of ZnFe2O4-TiO2nanoparticles inside the pores of the mesoporous MCM-41 host without destroying its integrity. ZnFe2O4nanoparticles can inhibit the transformation of anatase into rutile phase of TiO2. Incorporation of ZnFe2O4-TiO2within MCM-41 avoided the agglomeration of nanoparticles and reduced the band gap energy of TiO2to enhance its visible light photocatalytic activity. UV-vis absorption edges of ZTM nanocomposites redshifted with the increase of Zn/Ti molar ratio. The nanocomposite approach could be a potential choice for enhancing the photoactivity of TiO2, indicating an interesting application in the photodegradation and photoelectric fields.

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