Influence of concentration in phosphoric acid treatment of titanium oxide and their powder properties

Onoda, Hiroaki; Matsukura, Aki

doi:10.1016/j.jascer.2014.10.003

Cited by 7 publications

(5 citation statements)

References 11 publications

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“…The other peak at 54° of the pure rutile TiO2 is absent in the diffractograms of PO4-TiO2 and SO4-TiO2. The PO4-TiO2 diffractogram shows characteristic peaks at 25°, 26°, 38°, 48°, 54° and 55° [22], whereas the characteristic peak of SO4-TiO2 clearly appears at 23° [31]. It can be observed from Table 1 that the mass content values of S in SO4-TiO2 and P in PO4-TiO2 measured by energy-dispersive X-ray spectroscopy (EDX) and inductively coupled plasma-atomic emission spectrophotometry (ICP-AES) are close.…”

Section: Characterization Of Po 4 -Tio 2 and So 4 -Tio 2 Doping Agentsmentioning

confidence: 82%

“…The diffractograms reveal that the PO 4 -TiO 2 and SO 4 -TiO 2 have different structures when compared to the original TiO 2 rutile phase, although they were submitted to the same temperature of calcination; this may be related to the different synthesis methods. The intensity of the peak of rutile TiO 2 at 28 • is reduced in the SO 4 [22], whereas the characteristic peak of SO 4 -TiO 2 clearly appears at 23 • [31]. It can be observed from Table 1 that the mass content values of S in SO 4 -TiO 2 and P in PO 4 -TiO 2 measured by energy-dispersive X-ray spectroscopy (EDX) and inductively coupled plasma-atomic emission spectrophotometry (ICP-AES) are close.…”

Section: Characterization Of Po 4 -Tio 2 and So 4 -Tio 2 Doping Agentsmentioning

confidence: 99%

“…The functionalization of TiO 2 either with the PO 4 3− anion or SO 4 2− anion was done by an impregnation-calcination method according to the literature [22][23][24] and is explained briefly herein. The PO 4 -TiO 2 powder was obtained as follows: TiO 2 powder was mixed with 0.1 M H 3 PO 4 in a 1:1 molar ratio and the solution was shaken in a water bath (80 • C).…”

Section: Synthesis Of Po 4 -Tio 2 and So 4 -Tio 2 Nanotubes Doping Agmentioning

confidence: 99%

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Synthesis and Characterization of Novel Green Hybrid Nanocomposites for Application as Proton Exchange Membranes in Direct Borohydride Fuel Cells

2020

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Organic–inorganic nanocomposite membranes for potential application in direct borohydride fuel cells (DBFCs) are formulated from sulfonated poly(vinyl alcohol) (SPVA) with the incorporation of (PO4-TiO2) and (SO4-TiO2) nanotubes as doping agents. The functionalization of PVA to SPVA was done by using a 4-sulfophthalic acid as an ionic crosslinker and sulfonating agent. Morphological and structural characterization by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) confirmed the successful synthesis of the doping agents and their incorporation into the polymer. The influence of PO4-TiO2 and SO4-TiO2 doping and their content on the physicochemical properties of the nanocomposite membranes was evaluated. Swelling degree and water uptake gradually reduced to 7% and 13%, respectively, with increasing doping agent concentration. Ion exchange capacity and ionic conductivity of the membrane with 3 wt.% doping agents were raised 5 and 7 times, respectively, compared to the undoped one. The thermal and oxidative stability and tensile strength also increased with the doping content. Furthermore, lower borohydride permeability (0.32 × 10−6 cm2 s−1) was measured for the membranes with higher amount of inorganic doping agents when compared to the undoped membrane (0.71 × 10−5 cm2 s−1) and Nafion®117 (0.40 × 10−6 cm2 s−1). These results pave the way for a green, simple and low-cost approach for the development of composite membranes for practical DBFCs.

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Section: Characterization Of Po 4 -Tio 2 and So 4 -Tio 2 Doping Agentsmentioning

confidence: 82%

Section: Characterization Of Po 4 -Tio 2 and So 4 -Tio 2 Doping Agentsmentioning

confidence: 99%

Section: Synthesis Of Po 4 -Tio 2 and So 4 -Tio 2 Nanotubes Doping Agmentioning

confidence: 99%

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Synthesis and Characterization of Novel Green Hybrid Nanocomposites for Application as Proton Exchange Membranes in Direct Borohydride Fuel Cells

2020

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“…As can be observed, the samples Nb/SiO 2 -TiO 2 and those treated with 0.20 M or less H 3 PO 4 did not exhibit any peaks in the X-ray di ractograms, strongly suggesting that they were amorphous. An H 3 PO 4 treatment has been claimed to facilitate well dispersion of Nb on catalyst supports (Onoda and Matsukura, 2015) . The amorphous nature of the samples could be also due to the small amount of both TiO 2 and Nb in the samples.…”

Section: Properties Of Materialsmentioning

confidence: 99%

Properties and Bifunctional Catalytic Activity of Niobium-Doped Silica-Titania: Effect of Phosphoric Acid Treatment

Lee

Ekhsan

Ling

2022

Sci. Technol. Indones

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The effect of phosphoric acid treatment on the physical-chemical properties and catalytic activity of the niobium-doped silica-titania bifunctional catalyst was investigated. As part of the synthesis procedure to produce xPO4−/Nb/TiO2-SiO2, different concentrations of phosphoric acid (H3PO4) were used (x= 0, 0.05, 0.10, 0.15, 0.20, 0.25 M). As shown by XRD analysis, the samples synthesized using 0–0.20 M H3PO4 were in amorphous form, as featureless diffractograms were obtained, indicating the PO4− groups were dispersed homogeneously on the surface of Nb doped SiO2-TiO2. Due to the increased concentration of acid, other compounds were formed in the samples by reactions between PO4− and Nb and/or Ti. Additionally, UV-Vis DRS results indicated that the presence of the PO4− group accelerated the transformation of hydrated tetrahedral Ti species into isolated tetrahedral Ti species. An experimental investigation of the catalytic performance of the catalyst was conducted using 1,2-epoxyoctane as an oxidant for the epoxidation of 1-octene to 1,2-octanediol. It has been demonstrated that H3PO4 treatment was essential for oxidative and acidity active site formation. The current research findings strongly suggested that Nb-doped TiO2-SiO2 treated with 0.2 M H3PO4 was the most effective bifunctional catalyst in generating 1,2-octanediol.

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“…Iron titanium phosphates have been used as the electrode materials for hydrogen production [10]. Among them, titanium phosphate (TiP) materials have attracted widespread attention for their applications on electrode [11,12], cosmetics [13], and adsorbents [14]. But there are very limited studies on the photocatalytic properties of TiP materials.…”

Section: Introductionmentioning

confidence: 99%

Hierarchical flower-like titanium phosphate derived from H-titanate nanotubes for photocatalysis

et al. 2015

J Mater Sci

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Nanosheet-assembled hierarchical flower-like titanium phosphate (TiP) is synthesized via hydrothermal treatment of H-titanate nanotubes (Ti-NT) at the optimized conditions of 0.1 M of H 3 PO 4 and hydrothermal temperature of 130°C. A possible formation mechanism for the TiP flowers, involving the disintegration of Ti-NT and the growth and assembling of TiP nanosheets, is proposed. The main compositions of the uncalcined TiP flowers are titanium hydrogen phosphate hydrates (Ti(HPO 4 ) 2 ÁxH 2 O), which can be transformed to titanium phosphate (TiP 2 O 7 ) after high temperature calcination. The photocatalytic activity of the prepared TiP flowers is increased with the increased calcination temperature, which may be attributed to the better photocatalytic activity of TiP 2 O 7 than Ti(HPO 4 ) 2 ÁxH 2 O and the increased crystallization of TiP 2 O 7 .

show abstract

Influence of concentration in phosphoric acid treatment of titanium oxide and their powder properties

Cited by 7 publications

References 11 publications

Synthesis and Characterization of Novel Green Hybrid Nanocomposites for Application as Proton Exchange Membranes in Direct Borohydride Fuel Cells

Synthesis and Characterization of Novel Green Hybrid Nanocomposites for Application as Proton Exchange Membranes in Direct Borohydride Fuel Cells

Properties and Bifunctional Catalytic Activity of Niobium-Doped Silica-Titania: Effect of Phosphoric Acid Treatment

Hierarchical flower-like titanium phosphate derived from H-titanate nanotubes for photocatalysis

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