Effect of particle size and local disorder on specific surface area of layered double hydroxides upon calcination-reconstruction

Gwak, Gyeong‐Hyeon; Okada, Tomohiko; Oh, Jae‐Min

doi:10.1016/j.jssc.2018.03.041

Cited by 50 publications

(36 citation statements)

References 29 publications

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“…Also, the calcination process at 750 o C let to the increasing of the surface area. This behavior is consistent with similar results from the literature [23,24]. The XRF analysis was used to determine the samples elemental composition in the nearby of the surface (Table 5).…”

Section: Theta Degreesupporting

confidence: 89%

On tuning architectonics of nanoscaled assemblies of Zn-Ga-Al -based oxides obtained from layered double hydroxides precursors

Ignat¹,

Cârjă²,

Romila³

et al. 2019

Preprint

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Nanoscaled self-assemblies with engineered architectonics are important for obtaining advanced materials with specific applications in nanotechnology. We investigated here the morphology features at the nanoscale of the assemblies of the mixed oxides obtained through the thermal transformation of Zn2+Me3+ (Me=Al/Ga) layered double hydroxides (LDHs), as their “as-synthesized” form or after they were reconstructed in the aqueous solution of Ga2(SO4)3. The characteristics of ZnMe LDHs and the derived assemblies of mixed oxides were assessed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM/EDX), N2 adsorption at −196°C and thermal analyses (TG/DTG/DSC). The results revealed the formation nanoscaled assemblies of ZnO/ZnAl2O4/ZnGa2O4 and ZnO/Ga2O3/ZnGa2O4 starting from ZnMe(Me=Al/Ga) as precursors. Results point out that both the composition of the LDHs and the calcination temperatures can be used as parameters for tuning the nanomorphology features of the studied mixed oxides.

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Section: Theta Degreesupporting

confidence: 89%

On tuning architectonics of nanoscaled assemblies of Zn-Ga-Al -based oxides obtained from layered double hydroxides precursors

Ignat¹,

Cârjă²,

Romila³

et al. 2019

Preprint

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“…. As reported by Kim et al[22] a partial crystal deformation of double-layered hydroxides occurs upon calcination, in which octahedral Al(OH) 6 migrates to tetrahedral AlO 4 resulting in the enhancement of S BET . In our case, the increase in specific surface area can be linked with the creation of narrower pores in Y-modified materials.…”

mentioning

confidence: 63%

“…Interlayer anions, e.g. water molecules and/or carbonates, compensate the positive charge and they may also be exchanged for catalytically active components [3,14,[18][19][20][21][22]. Moreover, acid-base properties can be tailored, as reported e.g.…”

Section: Introductionmentioning

confidence: 99%

Yttrium promoted Ni-based double-layered hydroxides for dry methane reforming

Świrk

Gálvez

Motak

et al. 2018

Journal of CO2 Utilization

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Yttrium modified Ni-based double-layered hydroxides were tested as novel catalysts in dry methane reforming. The catalysts were characterized by XRF, BET analysis, XRD, TPR-H 2 , TPD-CO 2 , TGA/DSC-MS, H 2 chemisorption and TEM. Co-precipitation with yttrium (III) nitrate hexahydrate resulted in increased specific surface area, smaller Ni crystallite size, enhanced reducibility, and higher distribution of weak and medium basic sites as compared to Y-free material. The DRM catalytic tests, carried out in the temperature range of 850-600 ºC, led to a significant improvement of activity, with the 1.5 wt % Y-promoted catalyst being the most efficient in converting both CH 4 and CO 2. Moreover, the 10 h test at 700 ºC further confirmed enhanced stability for this HTNi-Y1.5 catalyst. Higher CO 2 conversion than CH 4 conversion and less CO compared to H 2 proves that side reactions are occurring simultaneously.

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“…The final LDHMF catalytic precursor is recovered thanks to the memory effect, a property characteristic of the laminar double hydroxide materials [50][51][52]. Said precursor can be reactivated for a second cycle as a catalyst for the degradation of 2,4,6-trichlorophenol.…”

Section: Ldhmf-400 °Cmentioning

confidence: 99%

Photocatalytic Degradation of 2,4,6-Trichlorophenol by MgO–MgFe2O4 Derived from Layered Double Hydroxide Structures

et al. 2019

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In recent years, the search for solutions for the treatment of water pollution by toxic compounds such as phenols and chlorophenols has been increasing. Phenols and their derivatives are widely used in the manufacture of pesticides, insecticides, paper, and wood preservers, among other things. Chlorophenols are partially biodegradable but not directly photodegradable by sunlight and are extremely toxic—especially 2,4,6-trichlorophenol, which is considered to be potentially carcinogenic. As a viable proposal to be applied in the treatment of water contaminated with 2,4,6-trichlorophenol, this paper presents an application study of the thermally activated Mg/Fe layered double hydroxides as photocatalysts for the mineralization of this contaminant. Activated Mg/Fe layered double hydroxides were characterized by X-ray diffraction, thermal analysis, N2 physisorption, and scanning electron microscopy with X-ray dispersive energy. The results of the photocatalytic degradation of 2,4,6-trichlorophenol in aqueous solution showed good photocatalytic activity, with an efficiency of degradation of up to 93% and mineralization of 82%; degradation values which are higher than that of TiO2-P25, which only reached 18% degradation. The degradation capacity is attributed to the structure of the MgO–MgFe2O4 oxides derived from double laminate hydroxide Mg/Fe. A path of degradation based on a mechanism of superoxide and hollow radicals is proposed.

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Effect of particle size and local disorder on specific surface area of layered double hydroxides upon calcination-reconstruction

Cited by 50 publications

References 29 publications

On tuning architectonics of nanoscaled assemblies of Zn-Ga-Al -based oxides obtained from layered double hydroxides precursors

On tuning architectonics of nanoscaled assemblies of Zn-Ga-Al -based oxides obtained from layered double hydroxides precursors

Yttrium promoted Ni-based double-layered hydroxides for dry methane reforming

Photocatalytic Degradation of 2,4,6-Trichlorophenol by MgO–MgFe2O4 Derived from Layered Double Hydroxide Structures

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