TiO2-loaded Nafion membranes: An electron microscope investigation

Albu‐Yaron, Ana; Arcan, Lelia; Heitner-Wirguin, C.

doi:10.1016/0040-6090(90)90017-8

Cited by 17 publications

(13 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, the bands appearing at 970–983 cm –1 are attributed to C–O–C stretching vibrations; the band at ∼1066 cm –1 can be related to the symmetric stretching of −SO 3 –. In the range between 1400 and 1100 cm –1 the asymmetric stretching bands of −SO 3 – should be found, but they are covered from the more intense bands of −CF 2 stretching, visible in the spectra . Moreover, interactions between the Nafion matrix and the loaded C 3 N 4 occur as already reported in the literature by Wu et al The C 3 N 4 nanosheets consist of a two-dimensional material that through amine groups establish cross-linking interactions with the hydrophilic −SO 3 – groups present in the Nafion matrix.…”

Section: Resultssupporting

confidence: 51%

“…In the range between 1400 and 1100 cm −1 the asymmetric stretching bands of −SO 3 − should be found, but they are covered from the more intense bands of −CF 2 stretching, visible in the spectra. 40 Moreover, interactions between the Nafion matrix and the loaded C 3 N 4 occur as already reported in the literature by Wu et al 41 The C 3 N 4 nanosheets consist of a two-dimensional material that through amine groups establish cross-linking interactions with the hydrophilic −SO 3 − groups present in the Nafion matrix. FT-IR/ATR analysis of C 3 N 4 Nafion membrane shows, with respect to Nafion membrane, a blue shift of SO 3 -characteristic asymmetric vibration from 1054 to 1063 cm −1 (Figure 5a, inset).…”

Section: ■ Materials and Methodssupporting

confidence: 60%

See 1 more Smart Citation

CO₂ to Liquid Fuels: Photocatalytic Conversion in a Continuous Membrane Reactor

Pomilla

Brunetti

Marcı̀

et al. 2018

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

The photocatalytic reduction of CO2 into value-added chemicals using sunlight is a promising approach to promote energy-bearing products, mitigating the adverse effects of anthropogenic CO2 emissions. In this work, exfoliated C3N4 was incorporated into Nafion matrix and used in a continuous photocatalytic reactor for converting CO2 into liquid fuels. Comprehensive structural and morphological diffuse reflectance spectroscopy (DRS), FT-IR, ATR-IR, and SEM measurements were performed for C3N4-loaded Nafion membrane and then compared with those of a Nafion membrane without any catalyst. The synergic effect of C3N4 organic catalyst embedded in a Nafion dense matrix and a continuous operating mode of the photoreactor was successfully accomplished for the first time, as yet absent in the literature, analyzing the reactor performance as a function of key parameters such as contact time and H2O/CO2 feed molar ratio. The reactor performance was analyzed under UV–vis light in terms of productivity, selectivity, and converted carbon. Alcohol (MeOH + EtOH) production was 32.8 μmol gcatalyst –1 h–1 corresponding to 47.6 μmol gcatalyst –1 h–1 of total converted carbon per gram of catalyst at the best operating conditions. So far, this value results as higher than most of the literature values reported up to date. Moreover, the membrane reactor converted at least 10 times more carbon than the batch system, as a result of the catalyst embedding in a Nafion matrix.

show abstract

Section: Resultssupporting

confidence: 51%

Section: ■ Materials and Methodssupporting

confidence: 60%

CO₂ to Liquid Fuels: Photocatalytic Conversion in a Continuous Membrane Reactor

Pomilla

Brunetti

Marcı̀

et al. 2018

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…Nafion is the most widely studied perfluorinated ionomer membrane . Thin films of Nafion membrane have been used as templates for the synthesis of nanoscale semiconductor and metal particles, including TiO 2 nanoparticles. − In fact, the study of the nanoparticle formation in Nafion membrane carries dual purposes. On one hand, a combination of the superior material properties of Nafion membrane with the high catalytic activities of nanocrystalline TiO 2 provides a unique platform for the development of supported photocatalysts. − On the other hand, crystalline TiO 2 nanoparticles may serve as nanoscale probes in an understanding of the Nafion membrane structure as related to its templating effects on the formation of nanoparticles .…”

Section: Introductionmentioning

confidence: 99%

Formation of Nanocrystalline Titanium Dioxide in Perfluorinated Ionomer Membrane

et al. 2002

View full text Add to dashboard Cite

The formation of crystalline titanium dioxide (TiO2) nanoparticles in Nafion membrane structure was investigated. The X-ray powder diffraction and high-resolution transmission electron microscopy (TEM) results show that these nanoparticles are pure anatase TiO 2. The TEM results also show that the crystalline TiO2 nanoparticles are ellipse in shape, with an estimated average aspect ratio (long axis/short axis) of 1.4. The average size of the TiO2 nanoparticles, which is independent of the loading of titanium, is similar to the estimated dimensions of the hydrophilic cavities in Nafion membrane in terms of the ion cluster model. However, there is no evidence for any TiO 2 nanoparticles in the proposed channels that connect the hydrophilic cavities. The fact that the TiO2 nanoparticles are distributed homogeneously throughout the Nafion membrane structure suggests that the nanoparticles-embedded membrane still maintains a certain degree of porosity. The properties and potential applications of the Nafion-supported crystalline TiO 2 nanoparticles are discussed.

show abstract

“…The perfluorosulfonic ionomer Nafion from DuPont is well suited for applications such as this due to its microstructure of 40 A ˚inverted micelles that can take up water and in which the sulfonate groups (terminating the long pendant ether sidechains of the polymer) can act as ion-exchange sites. 1,2 Several studies of oxides incorporated into the Nafion membrane have been made over the last fifteen years, for example, Fe-oxide, [3][4][5][6][7][8] Pb-oxide, 9 Ruoxide, [10][11][12] Ti-oxide, 8,[13][14][15][16][17][18] U-oxide 12 and W-oxide. 19 Many different oxides have thus been incorporated into Nafion, but so far none of the layered cathode materials used in state of the art rechargeable lithium ion and lithium polymer batteries have been tried.…”

Section: Introductionmentioning

confidence: 99%