Rice Husk Reuse in the Preparation of SnO2/SiO2Nanocomposite

Ferreira, Chayanne Silva; Santos, Pãmyla L. dos; Bonacin, Juliano Alves; Passos, Raimundo R.; Pocrifka, Leandro A.

doi:10.1590/1516-1439.009015

Cited by 89 publications

(21 citation statements)

References 40 publications

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“…The Raman spectrum of SnO 2 thin films is characterized by the classical vibrational bands observed at 474 (E g ), 632 (A 1g ) and 780 (B 2g ) cm −1 assigned to SnO 2 rutile structure (cassiterite) [13]. Ferreira et al [14] attributed the vibrational hump localized at 130 cm −1 to non degenerated B 1g mode of SnO 2 which is assigned to rotation of the oxygen atoms at tetragonal unit cell of rutile. Besides, we also observed other Raman peaks of 250 and 302 cm −1 which can be assigned to optical phonon modes of SnO 2 (Eu (LO) and Eu (TO)) [14,15].…”

Section: Raman Analysismentioning

confidence: 99%

“…Ferreira et al [14] attributed the vibrational hump localized at 130 cm −1 to non degenerated B 1g mode of SnO 2 which is assigned to rotation of the oxygen atoms at tetragonal unit cell of rutile. Besides, we also observed other Raman peaks of 250 and 302 cm −1 which can be assigned to optical phonon modes of SnO 2 (Eu (LO) and Eu (TO)) [14,15]. The peak localized at 558 cm −1 is assigned to SnO surface vibrations as suggested by Yang et al [16].…”

Section: Raman Analysismentioning

confidence: 99%

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Study of TiO₂, SnO₂ and nanocomposites TiO₂:SnO₂ thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Medjaldi

Bouabellou

Bouachiba

et al. 2020

Mater. Res. Express

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In this research TiO 2 , SnO 2 and TiO 2 :SnO 2 nanocomposite thin films were fabricated by the sol-gel dip coating technique. The mixture was prepared by varying the molar ratio of SnO 2 to TiO 2 , i.e. TiO 2 :SnO 2 (9:1), TiO 2 :SnO 2 (8:2) and TiO 2 :SnO 2 (6:4)). The obtained samples were characterized by means of the Raman microscopy, Scanning Electron Microscopy (SEM), UV-Vis spectrophotometry and m-lines spectroscopy (Prism coupler). Raman analysis shows that pure TiO 2 and SnO 2 thin films are characterized by the vibrational modes of anatase and rutile cassiterite, respectively. Furthermore, the Raman spectra of the TiO 2 :SnO 2 nanocomposites show the presence of a mixture of anatase and rutile TiO 2 phases. The SEM images reveal that the morphology is clearly modified with SnO 2 content. The ripples in the transmittance spectra decreased with increasing SnO 2 content. Also, the evolution of the optical band gap seems to be consistent with the Raman analysis. A great attention has been paid to the refractive index measurements by the prism coupler technique. In this way, variable-refractive index systems have been successfully obtained using TiO 2 :SnO 2 nanocomposite thin films.

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Section: Raman Analysismentioning

confidence: 99%

Section: Raman Analysismentioning

confidence: 99%

Study of TiO₂, SnO₂ and nanocomposites TiO₂:SnO₂ thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Medjaldi

Bouabellou

Bouachiba

et al. 2020

Mater. Res. Express

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“…The translational E g mode is due to the oxygen anions motion along the c-axis [36,37]. The band at 137 cm −1 is associated with B 1g mode and appears only in the spectra of nanocrystalline SnO 2 in the range of 100-184 cm −1 [38,39]. The second wide band at 563 cm −1 is associated with in-plane oxygen vacancies of the nanocrystalline SnO 2 [40][41][42].…”

Section: Characteristics Of Nanocrystalline Semiconductor Oxidesmentioning

confidence: 99%

Organic-Inorganic Hybrid Materials for Room Temperature Light-Activated Sub-ppm NO Detection

et al. 2019

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Nitric oxide (NO) is one of the main environmental pollutants and one of the biomarkers noninvasive diagnosis of respiratory diseases. Organic-inorganic hybrids based on heterocyclic Ru (II) complex and nanocrystalline semiconductor oxides SnO 2 and In 2 O 3 were studied as sensitive materials for NO detection at room temperature under periodic blue light (λ max = 470 nm) illumination. The semiconductor matrixes were obtained by chemical precipitation with subsequent thermal annealing and characterized by XRD, Raman spectroscopy, and single-point BET methods. The heterocyclic Ru (II) complex was synthesized for the first time and characterized by 1 H NMR, 13 C NMR, MALDI-TOF mass spectrometry and elemental analysis. The HOMO and LUMO energies of the Ru (II) complex are calculated from cyclic voltammetry data. The thermal stability of hybrids was investigated by thermogravimetric analysis (TGA)-MS analysis. The optical properties of Ru (II) complex, nanocrystalline oxides and hybrids were studied by UV-Vis spectroscopy in transmission and diffuse reflectance modes. DRIFT spectroscopy was performed to investigate the interaction between NO and the surface of the synthesized materials. Sensor measurements demonstrate that hybrid materials are able to detect NO at room temperature in the concentration range of 0.25-4.0 ppm with the detection limit of 69-88 ppb.Nanomaterials 2020, 10, 70 2 of 22 in noninvasive diagnosis of respiratory diseases [7][8][9]. In this case, the limitation of the quantitative determination of NO in exhaled air is due to the low level of its concentration (20-200 ppb) among a wide range of interfering gases [10].Direct determination of nitrogen monoxide in the gas phase is possible using conductometric gas sensors based on various semiconductor metal oxides [7,[10][11][12][13][14][15][16][17][18][19][20][21][22]. To increase selectivity of such analysis along with lower power consumption, complete or partial replacement of thermal heating with photoactivation is a promising approach. Activation of the sensor response under illumination occurs through various mechanisms depending on the nature of the target gas. For oxidizing gases (NO 2 , O 3 ), which compete with oxygen for the same adsorption sites, photogeneration of electron-hole pairs plays a major role in the photodesorption process. On the contrary, for the detection of reducing gases (CO, NH 3 , H 2 S), the presence of chemisorbed oxygen on the surface of the semiconductor oxide is necessary. In this case, the increase in the sensor response under illumination is due to the unpinning of Fermi level of the semiconductor. In most works NO is detected as oxidizing gas. The similar routes of NO and NO 2 sensing was recently evidenced by in situ DRIFT spectroscopy [23]. Our previous works show that highly selective NO 2 detection is possible using visible light photoactivation [24][25][26][27]. To shift the optical sensitivity of semiconductor oxides into the visible range, it is necessary to create defects in the semiconductor matrix or i...

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“…The peaks~16 • , 22 • , and 35 • are attributed to cellulose [43,44], which exhibits the crystalline structure due to hydrogen bonding interactions and Van der Waals forces between adjacent molecules [45,46]. The RHA shows a broad peak~22 • (2θ) for amorphous silica and cellulose [44,47,48]. The major crystalline phase in slag corresponds to CaCO 3 [49].…”

Section: X-ray Diffraction (Xrd)mentioning

confidence: 99%

Development of Green Geopolymer Using Agricultural and Industrial Waste Materials with High Water Absorbency

et al. 2017

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Abstract:Geopolymer is a promising porous material that can be used for evaporative cooling applications. Developing a greener geopolymer using agricultural and industrial wastes is a promising research area. In this study, we utilize rice husk (RH), rice husk ash (RHA), metakaolin (MK), ground granulated blast furnace slag (GGBS), and palm oil fuel ash (POFA) to prepare geopolymer pastes, with alkali liquid as an activator. Many geopolymer samples have been prepared as per the Design of Experimental software (DOE), and its corresponding response surface mode and central composite design and later they were characterized. The samples were cured in an oven for 2 h at 80 • C, and thereafter stored at room temperature (~25-30 • C) prior to being tested for its water absorption and compressive strength. The effect of the different composition of precursors on water absorption, density, porosity, and the compressive strength of the prepared geopolymers have been investigated. The results showed that the compressive strength of geopolymers is directly proportional to the ratio of the alkali liquid. Post-optimization, the best geopolymer paste mixture was confirmed to contain 10% of RH, 15% RHA, 35% MK, 10% POFA and 30% of GGBS, with 72% desirability for maximum water absorption (~38%) and compressive strength (4.9 MPa). The results confirmed its applicability for evaporative cooling.

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Rice Husk Reuse in the Preparation of SnO2/SiO2Nanocomposite

Cited by 89 publications

References 40 publications

Study of TiO₂, SnO₂ and nanocomposites TiO₂:SnO₂ thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Study of TiO₂, SnO₂ and nanocomposites TiO₂:SnO₂ thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Organic-Inorganic Hybrid Materials for Room Temperature Light-Activated Sub-ppm NO Detection

Development of Green Geopolymer Using Agricultural and Industrial Waste Materials with High Water Absorbency

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Rice Husk Reuse in the Preparation of SnO2/SiO2Nanocomposite

Cited by 89 publications

References 40 publications

Study of TiO2, SnO2 and nanocomposites TiO2:SnO2 thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Study of TiO2, SnO2 and nanocomposites TiO2:SnO2 thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Organic-Inorganic Hybrid Materials for Room Temperature Light-Activated Sub-ppm NO Detection

Development of Green Geopolymer Using Agricultural and Industrial Waste Materials with High Water Absorbency

Contact Info

Product

Resources

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Study of TiO₂, SnO₂ and nanocomposites TiO₂:SnO₂ thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems

Study of TiO₂, SnO₂ and nanocomposites TiO₂:SnO₂ thin films prepared by sol-gel method: Successful elaboration of variable–refractive index systems