Layered Double Hydroxides as Bifunctional Catalysts for the Aryl Borylation under Ligand-Free Conditions

Silva, Lorenna C. L. L. F.; Neves, Vinícius A.; Ramos, Vitor Santos; Silva, Raphael S. F.; Campos, José Brant de; Silva, Alexsandro A. da; Malta, Luiz Fernando B.; Senra, Jaqueline D.

doi:10.3390/catal9040302

Cited by 10 publications

(5 citation statements)

References 26 publications

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“…A similar increase in pH of water leachate from concrete bricks was reported by Nguyen et al (2020b). An increase of leachate pH and the presence of Ca in concrete and added lime would have resulted in the formation of Ca-As precipitates (calcium arsenate, calcium arsenite, calcium hydrogen arsenate hydrate, and calcium hydrogen arsenate), and this might have reduced the concentration of As in the leachate (Jing et al, 2005;Silva et al, 2019).…”

Section: As Leaching From Concrete Brickssupporting

confidence: 65%

Low-cost laterite-laden household filters for removing arsenic from groundwater in Vietnam and waste management

Nguyen

Loganathan

et al. 2021

Process Safety and Environmental Protection

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This study evaluated the performance of a low-cost natural laterite from Thach That (NLTT), Vietnam, for its arsenic (As) removal capacity in a household filter with contaminated groundwater. The NLTT was initially tested in a laboratory column trial lasting 800 h. The breakthrough curves were found to fit the Thomas model very satisfactorily with adsorption capacities of 0.06 and 0.20 mg/g at a flow velocity of 0.85 m/h for the influent As(V) concentrations of 0.1 and 0.5 mg/L, respectively. In household filters at four sites, the median As concentration in groundwaters (0.04-0.19 mg/L) dropped to 0.026-0.054 mg/L after traditional sand filtration. However, after the subsequent NLTT filtration through columns (14 cm inner diameter, 65 cm height) at 0.65 m/h flow velocity, it fell to below the Vietnam and WHO drinking water standard (0.01 mg/L) during seven months of continuous operation.Portland cement and lime were tested as binding agents for the exhausted NLTT waste in a solidification/stabilization process at different ratios. The best ratio of exhausted NLTT: Portland cement: lime for restraining mobility of As from this waste was 3: 1: 0.5. The concrete brick products revealed a suitable compressive strength for using it as building materials in construction work.

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Section: As Leaching From Concrete Brickssupporting

confidence: 65%

Low-cost laterite-laden household filters for removing arsenic from groundwater in Vietnam and waste management

Nguyen

Loganathan

et al. 2021

Process Safety and Environmental Protection

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“…The Zaccagnaite phase was obtained as the majority phase with most intense peaks at 11.65° (003) and 23.51° (006) whereas the Zincite phase shows reflections at 31.84° (101), 34.85° (009) and 36.36° (104). Zaccagnaite mineral is a Zn‐Al hydrotalcite prototype confirming the ratio of Zn and Al as 2:1 35 . The observed phases also reveal the hexagonal (P‐63 m c) with trigonal crystal (R‐3 m) structure and rhombohedral lattice system of the Zn‐Al LDH 36 …”

Section: Resultsmentioning

confidence: 65%

“…The average crystallite size of the LDH nanosheets was calculated to be ⁓20 nm along (003) plane. 35 The observed phases also reveal the hexagonal (P-63 m c) with trigonal crystal (R-3 m) structure and rhombohedral lattice system of the Zn-Al LDH. 36 The XRD patterns of pristine PVA and ZnAl LDH nanocomposite are measured and the degree of crystallinity (X d %) of the PVA nanocomposite was also calculated using Hermans-Weidinger approach as:…”

Section: Structural Analysis Of Znal Ldh and Nanocomposite Samplesmentioning

confidence: 84%

Remarkable tailoring of thermal and dielectric properties of poly(vinyl alcohol) nanocomposite via hydrothermal grown ZnAl layer di hydroxide nanostructures and graphene fillers

Ritu,

Patel,

Gupta

2023

Vinyl Additive Technology

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In this work, we have synthesized the zinc‐aluminum layered double hydroxide (ZnAl LDH) nanostructures using cost‐effective hydrothermal technique. The ZnAl LDH and graphene‐based poly(vinyl alcohol) (PVA) nanocomposites are fabricated. The crystal structure, morphology, thermal, and dielectric properties of pristine PVA and ZnAl LDH and graphene‐based PVA nanocomposites films were investigated using X‐ray diffraction, HR‐transmission electron microscopy, thermo gravimetric analysis, and impedance analyzer. HRTEM analysis reveals the hexagonal nanoplates shape‐like morphology of Zn‐Al layered double hydroxides with an average thickness of 40–50 nm and size of 400–600 nm. High thermal stability was observed from ZnAl LDH and graphene‐reinforced nanocomposite. Enhanced thermal stability of 250°C and low weight loss was observed from ZnAl LDH reinforced PVA‐based nanocomposites compared to pristine PVA. Zn‐Al LDH nanoplates‐graphene‐PVA based nanocomposites showed ultra‐high dielectric constant (ɛ′) of 794 as compared to the ZnAl LDH‐PVA nanocomposites (ɛ′ ~ 334) and pristine PVA sample (ɛ′ ~ 35). Low dielectric loss of 0.27, 0.18, 0.38 was observed for pristine PVA, ZnAl‐LDH‐PVA and ZnAl‐LDH‐graphene‐PVA nanocomposites. The large enhancement of the dielectric constant and thermal stability were discussed in terms of improved crystallinity, interfacial polarization and formation of nanodipoles in the matrix. This study reveals a significant role of LDH‐graphene‐based hybrid nanocomposites in optoelectronics, energy storage, sensors, energy conversion and thermally stable devices.Highlights Growth of highly crystalline zinc‐aluminum layered double hydroxide nanostructures. Improved thermal stability for Zn‐Al LDH‐graphene‐PVA nanocomposites. High thermal stability from ZnAl LDH‐based PVA nanocomposites. Ultra‐high dielectric constant of 794 is observed from Zn‐Al LDH nanoplates‐graphene‐nanocomposites.

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“…Layered double hydroxides (LDHs) have attracted increasing attention based on their large interlayer surface area and potential applications, including as adsorbents, catalysts, and catalyst supports [24][25][26][27][28][29]. The general structural formula of hydrotalcite-like samples (HTLs) can be written as [M 2] x+ [A n− x/n] x− •zH2O, where M 2+ (such as Mg 2+ , Ca 2+ , Zn 2+ ) and M 3+ (Al 3+ , Fe 3+ , etc.)…”

Section: Introductionmentioning

confidence: 99%

HCl Removal Using Calcined Ca–Mg–Al Layered Double Hydroxide in the Presence of CO2 at Medium–High Temperature

Wang

et al. 2019

Catalysts

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This present work aimed to investigate the influence of CO2 on HCl removal using calcined Ca–Mg–Al layered double hydroxides (CaMgAl-LDHs) at medium–high temperature (400–800 °C) in a fixed-bed reactor. It was revealed that a moderate CO2 concentration (~6%) in the flue gas of the municipal solid-waste incinerators could reduce the HCl capacity of the CaMgAl-layered double oxides (CaMgAl-LDOs). The highest capacity for HCl removal was observed over the CaMgAl-LDOs at 600 °C. However, sintering was also detected when the reaction temperature was below the calcination temperature (600 °C). Moreover, the decreasing HCl adsorption capacity of CaMgAl-LDOs was attributed to the existence of CO2 in the flue gas, which could efficiently inhibit the decomposition of carbonates as well as the conversion into metal chloride during the HCl removal process.

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Layered Double Hydroxides as Bifunctional Catalysts for the Aryl Borylation under Ligand-Free Conditions

Cited by 10 publications

References 26 publications

Low-cost laterite-laden household filters for removing arsenic from groundwater in Vietnam and waste management

Low-cost laterite-laden household filters for removing arsenic from groundwater in Vietnam and waste management

Remarkable tailoring of thermal and dielectric properties of poly(vinyl alcohol) nanocomposite via hydrothermal grown ZnAl layer di hydroxide nanostructures and graphene fillers

HCl Removal Using Calcined Ca–Mg–Al Layered Double Hydroxide in the Presence of CO2 at Medium–High Temperature

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