Structural investigations on inorganic Al2O3–ZnO composites

El-Damrawi, G.; Salaheldin, Hosam I; Abd‐Elghany, Mohamed

doi:10.1007/s00339-020-04268-w

Cited by 5 publications

(4 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been reported that the binding energy of Al will shift to a lower value when Al forms doping in ZnO. , Solid–state 27 Al nuclear magnetic resonance (NMR) spectroscopy was then performed to investigate the coordination states of Al (Figure b). The three peaks shown in PEO/Al 2 O 3 corresponded to AlO 6 , AlO 5 , and AlO 4 coordinated in VPI-Al 2 O 3 , which was consistent with our previous report . The AlO 4 peak increased dramatically at the expense of AlO 6 and AlO 5 in PEO/AZO, demonstrating that most of the Al in PEO/AZO was doped into ZnO.…”

Section: Resultssupporting

confidence: 92%

Incorporating Binary Metal Oxides in Poly(ethylene oxide)-Based Solid Electrolytes by Vapor Phase Infiltration

Bao

Zhang

Shang

et al. 2023

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Vapor phase infiltration (VPI) derived from atomic layer deposition (ALD) enables inorganic materials to nucleate and grow within the free volume of polymers, which has shown promising prospects in the field of composite solid polymer electrolytes (CSPEs). However, there are only a few types of metal oxides that can be incorporated into the polymer matrix by VPI, let alone binary metal oxides, due to the limited knowledge of the VPI synthesis process. To combine the merits of different metal oxides, we investigate the VPI method to prepare ZnO-Al2O3 composites in poly(ethylene oxide) (PEO). When the introducing order is Al2O3/ZnO (AZO), due to the extremely high reactivity of trimethyl aluminum (TMA) with PEO, VPI-Al2O3 will accumulate near the surface of PEO. The surface Al2O3 layer inhibits the further diffusion of the diethyl zinc (DEZ) into the PEO matrix, leading to weak polymer–filler interactions and limited improvement of the Li+ conduction. In the incorporation order of ZnO/Al2O3 (ZAO), the moderate reactivity of DEZ renders the uniform distribution of VPI-ZnO within PEO, and the following TMA can both react with PEO and VPI-ZnO particles near the surface of PEO, which not only preserves the interactions between VPI-ZnO and PEO but also better inhibits the growth of lithium dendrites. The incorporation order plays a crucial role in the morphology and composition of binary metal oxides synthesized by VPI.

show abstract

Section: Resultssupporting

confidence: 92%

Incorporating Binary Metal Oxides in Poly(ethylene oxide)-Based Solid Electrolytes by Vapor Phase Infiltration

Bao

Zhang

Shang

et al. 2023

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…The 27 Al NMR spectroscopy is widely used to clarify the local aluminum environment in various materials. In aluminate, the Al atom usually existed in four-fold coordination, five-fold coordination, and six-fold coordination. , As shown in Figure c, the [AlO 4 ], [AlO 5 ], and [AlO 6 ] are revealed to exist in phosphors corresponding to three kinds of 27 Al chemical shift of 77–82, 25–35, and 10–15 ppm, respectively. , The phosphors clearly show main resonances assigned to [AlO 4 ] (higher chemical shift) since the aluminum mainly exists as [AlO 4 ] in the two crystal structures of Ba 2 ScAlO 5 . The appearance of [AlO 5 ] and [AlO 6 ] may be due to the structural defects caused by the doping of Eu 3+ and the formation of small impurity phases, such as EuCaAl 3 O 7 and Ba 5 Sc 4 AlO 12.5 .…”

Section: Resultsmentioning

confidence: 94%

Synthesis of the Red-Emitting (Ba, Ca)₂ScAlO₅:Eu³⁺ Phosphors with Photoluminescence Properties

et al. 2022

View full text Add to dashboard Cite

The light-emitting diodes (LED) are regarded as one of the most promising devices for inexpensive and widely used illumination; in particular, they are highly dependent on the development of red-emitting phosphors. Herein, we developed two types of red-emitting (Ba, Ca) 2 ScAlO 5 :Eu 3+ multiple excitations phosphors (λ ex = 255−465 nm) via freeze-drying followed by calcination. Powder X-ray diffraction and NMR results point out that they have hexagonal space group P6 3 /mmc (194), and the structural framework is composed of multi-coordinated Al 3+ −O 2− polyhedron and Sc 3+ −O 2− polyhedron. In addition, the valence state of europium (Eu 3+ ) is confirmed by X-ray photoelectron spectroscopy characterization. Investigation on the photoluminescence properties showed that the photoluminescence process of (Ba, Ca) 2 ScAlO 5 :Eu 3+ is attributable to the charge transfer band of Eu−O and abundant spectral terms of Eu 3+ . The α-(Ba, Ca) 2 ScAlO 5 :Eu 3+ and β-(Ba, Ca) 2 ScAlO 5 :Eu 3+ exhibited red emission under 465 and 395 nm excitation, respectively. The PL spectra and decay curves explain the intrinsic photoluminescence mechanism. The strongest emission peaks of the red-emitting α-(Ba, Ca) 2 ScAlO 5 :Eu 3+ and β-(Ba, Ca) 2 ScAlO 5 :Eu 3+ phosphors are at 615 and 619 nm, respectively, exhibiting a high fluorescence of 64 and 67% under the temperature of 423 K (150 °C). Further exploration of the red-emitting phosphors would provide a variety of choices for the design of red LEDs and white LEDs for the solid-state lighting system.

show abstract

“…While the first study by 27 Al NMR on ZnO:Al was published in 1997, [19] it is questionable if the study really was conducted on ZnO:Al or rather on a mixture of ZnO and ZnAl2O4 spinel, [20][21][22] because of the chosen synthesis conditions. Meanwhile ZnO:Al has been synthesized via different low temperature synthesis routes for example sol-gel synthesis [23] , chemical vapour deposition [24] , physical vapor deposition [25] or the calcination of hydroxycarbonate precursor materials, which corresponds to the synthesis method of industrial methanol synthesis catalysts. [26] Depending on the synthesis conditions used, different ZnO particle morphologies such as films [27] , rods [28] or nanoparticles [29] can be obtained.…”

Section: Introductionmentioning

confidence: 99%

A method for surface characterization using solid-state nuclear magnetic resonance spectroscopy demonstrated on nano-crystalline ZnO:Al

Konrad Wied,

Mockenhaupt,

Schürmann

et al. 2024

Preprint

View full text Add to dashboard Cite

Nano-scale zinc-oxide doped with aluminium ZnO:Al is studied by different techniques targeting surface changes induced by the conditions at which ZnO:Al is used as support material in the catalysis of methanol. While it is well established, that a variety of 1H and 27Al resonances can be found by solid-state NMR for this material, it was not clear yet which signals are related to species located close to the surface of the material and which to species located in the bulk. To this end, a method is suggested which makes use of a paramagnetically impregnated material to suppress NMR signals close to particle surface in the blind-sphere around the paramagnetic metal atoms. It is shown that it is important to use conditions which guarantee a stable reference system relative to which it can be established whether the coating procedure is conserving the original structure or not. This method, called Paramagnetically Assisted Surface Peak Assignment (PASPA), helped to assign the 1H and 27Al NMR peaks to the bulk and the surface layer defined by the blind- sphere of the paramagnetic atoms. The assignment results are further corroborated by the results from heteronuclear 27Al{1H} dipolar dephasing experiments, which indicate the hydrogen atoms are preferentially located in the surface layer and not in the particle core.

show abstract

Structural investigations on inorganic Al2O3–ZnO composites

Cited by 5 publications

References 19 publications

Incorporating Binary Metal Oxides in Poly(ethylene oxide)-Based Solid Electrolytes by Vapor Phase Infiltration

Incorporating Binary Metal Oxides in Poly(ethylene oxide)-Based Solid Electrolytes by Vapor Phase Infiltration

Synthesis of the Red-Emitting (Ba, Ca)₂ScAlO₅:Eu³⁺ Phosphors with Photoluminescence Properties

A method for surface characterization using solid-state nuclear magnetic resonance spectroscopy demonstrated on nano-crystalline ZnO:Al

Contact Info

Product

Resources

About

Structural investigations on inorganic Al2O3–ZnO composites

Cited by 5 publications

References 19 publications

Incorporating Binary Metal Oxides in Poly(ethylene oxide)-Based Solid Electrolytes by Vapor Phase Infiltration

Incorporating Binary Metal Oxides in Poly(ethylene oxide)-Based Solid Electrolytes by Vapor Phase Infiltration

Synthesis of the Red-Emitting (Ba, Ca)2ScAlO5:Eu3+ Phosphors with Photoluminescence Properties

A method for surface characterization using solid-state nuclear magnetic resonance spectroscopy demonstrated on nano-crystalline ZnO:Al

Contact Info

Product

Resources

About

Synthesis of the Red-Emitting (Ba, Ca)₂ScAlO₅:Eu³⁺ Phosphors with Photoluminescence Properties