TiO2‐SiO2/Ph‐POSS Functional Hybrids: Preparation and Characterisation

Nowacka, Magdalena; Ambrożewicz, Damian; Jesionowski, Teofil

doi:10.1155/2013/680821

Cited by 10 publications

(5 citation statements)

References 32 publications

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“…The SiO 2 (17.2%)/TiO 2 _400 sample showed the lowest zeta potential (+14.6 mV). Our observations agree with those of Nowacka et al [51], who found that the zeta potential decreases with increasing pH value, confirming that the zeta potential value strongly depends on pH.…”

Section: Characterization Of the Photocatalystssupporting

confidence: 93%

Synthesis and Characterization of SiO2/TiO2 as Photocatalyst on Methylene Blue Degradation

et al. 2022

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The paper presents a modification of titanium dioxide with fumed silica. The SiO2/TiO2 photocatalysts were obtained by the sol-gel method and then were calcined under an argon atmosphere. Various SiO2 weights (2–17.2 wt.%) were used in the materials’ preparation stage. The obtained samples were characterized using advanced analytical methods, such as FT-IR/DRS infrared spectroscopy, X-ray diffraction, SEM scanning electron microscopy, and UV-Vis/DRS spectroscopy. The BET specific surface area and zeta potential of samples were also measured. Based on the obtained results, it was observed that the modification of titanium dioxide with SiO2 effectively inhibited the increase in crystallite size of anatase and brookite during calcination and the decrease in specific surface area values. Moreover, the presence of SiO2 in the nanomaterials contributed to the increase in the size of specific surface area and the change in band gap energy values. The photocatalytic activity was determined based on the decomposition of methylene blue under UV irradiation. Thermal modification in an inert gas atmosphere significantly increased the dye removal rate. It should be noted that all the obtained SiO2/TiO2 photocatalysts showed higher activity compared to the starting TiO2. It was also found that the photocatalytic activity increased along with the increase in SiO2 content in the sample (up to 14.3 wt% of SiO2). The highest activity was recorded for SiO2(11.1%)/TiO2_400 and SiO2(14.3%)/TiO2_400 samples.

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Section: Characterization Of the Photocatalystssupporting

confidence: 93%

Synthesis and Characterization of SiO2/TiO2 as Photocatalyst on Methylene Blue Degradation

et al. 2022

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“…The following characteristic IR signals were observed for the two silicate-surface-modified catalysts: 670 cm -1 , Ti-O-Ti asymmetric stretching; 1060 cm -1 , Si-O-Si symmetric stretching; 960 cm -1 Si-O-Ti stretching; 3750 cm -1 , SiO-H extending and a broadband 3700-3500 cm -1 corresponding to water adsorbed on catalysts. These signals have also been identified in SiO2-TiO2 hybrid spheres and sol-gel TiO2-SiO2 films [39,40]. FT IR spectrum of am-P25, am-P25-SiO2, am-TiO2, and am-TiO2-SiO2 are shown in Figure S3.…”

Section: Catalysts Characterizationmentioning

confidence: 72%

In Water High Yield and Selectivity of CH4 and H2 Production Using UVC Light and a SiO2-surface-modified TiO2 Photocatalysts

Núñez,

Fereidooni,

Márquez

et al. 2023

Catal Res

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To improve CH4 and H2 formation from CO2 photoreduction using non-organic, non-laborious, and inexpensive photocatalysts, we have prepared two surface-silicate-modified TiO2 catalysts: P25-SiO2 and AmTiO2-SiO2 (amorphous TiO2) to be tested in water and using UV light. The last catalyst produces more CH4 and H2 in water than P25 (3:1 TiO2 anatase: rutile) under UV light irradiation of HCO3- and CO2; am-TiO2-SiO2 at pH = 7, produces 8 times more CH4 and H2 than P25 with selectivity at the reactor headspace of 30% and 53%, respectively. Using CO2 (pH = 3), 80 times more CH4 than P25 under the same conditions is obtained with a yield of 71%. This corresponds to a production of 8.9 μmol gcat-1·h-1, one of the highest reported rates of CH4 production from CO2 using carbon-free semiconductors. H2 is also produced by water splitting using Am-TiO2-SiO2 and water at low pH. The enhanced reactivity compared to P25 is attributed to three main factors: a) Low catalyst PZC (4.1) that facilitates CO2 adsorption and proton availability at the active site to catalyze the e transfer from Ti at the TiO2-SiO2-carbonate adduct b) SiO2 acts as electron trap reducing carriers recombination (External intramolecular trapping (EIT) mechanism) and c) am-TiO2-SiO2, light collection efficiency, surface area and irregular atoms distribution. Catalysts were also tested for Methylene blue (MB) photooxidation. P25 is quite a better catalyst in oxidizing MB via OH radicals, probably due to the more positive valence band potentials in the SiO2-modified catalysts that avoid the OH radical formation from water; however, when bicarbonate is added to MB solution, am-TiO2-SiO2 catalysts reactivity increases as a consequence of its valence band down-bending.

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“…Table 1 presents the weight percentages of Ti and Si according to the quantities of TEOS used in the preparation. Figures 3, 4, and 5 show the SEM images, Tauc's equation using the DRS UV-vis spectra of the P25 powder and PET-1.0Si-P25, and the FT-IR spectra of PET, the P25-SiO2 powder, and PET-1.0Si-P25 with the corresponding assignment of signals, respectively [20,21]. The plot of (αhν) 2 versus the photoenergy (hν) of each catalyst shown the curve line using the Tauc's relation (Figure 4), which intercepted on the photoenergy as its bandgap energy.…”

Section: Film Preparation and Characterizationmentioning

confidence: 99%

Photooxidation and Virus Inactivation using TiO2(P25)–SiO2 Coated PET Film

Autthanit

Jadsadajerm

Núñez

et al. 2022

Bull. Chem. React. Eng. Catal.

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This study chemically modified PET film surface with P25 using silicate as a binder. Different P25–binder ratios were optimized for the catalyst performance. The modified samples were analyzed by scanning electron microscopy-energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Diffuse reflectance UV-vis spectra revealed significant reductions in the band gaps of the P25 solid precursor (3.20 eV) and the surface-modified PET–1.0Si–P25 (2.77 eV) with visible light. Accordingly, under visible light conditions, catalyst activity on the film will occur. Additionally, the film’s performance was evaluated using methylene blue (MB) degradation. Pseudo-first-order-rate constants (min−1), conversion percentages, and rates (µg.mL−1.gcat−1.h−1) were determined. The coated films were evaluated for viral Phi–X 174 inactivation and tested with fluorescence and UV-C light illumination, then log (N/N0) versus t plots (N = [virus] in plaque-forming units [PFUs]/mL) were obtained. The presence of nanosilica in PET showed a high adsorption ability in both MB and Phi–X 174, whereas the best performances with fluorescent light were obtained from PET–1.0Si–P25 and PET–P25–1.0Si–SiO2 equally. A 0.2-log virus reduction was obtained after 3 h at a rate of 4×106 PFU.mL−1.gcat−1.min−1. Additionally, the use of this film for preventing transmission by direct contact with surfaces and via indoor air was considered. Using UV light, the PET–1.0Si–P25 and PET–1.0Si–P25–SiO2 samples produced a 2.5-log inactivation after 6.5 min at a rate of 9.6×106 and 8.9×106 PFU.mL−1.gcat−1.min−1, respectively. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

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TiO₂‐SiO₂/Ph‐POSS Functional Hybrids: Preparation and Characterisation

Cited by 10 publications

References 32 publications

Synthesis and Characterization of SiO2/TiO2 as Photocatalyst on Methylene Blue Degradation

Synthesis and Characterization of SiO2/TiO2 as Photocatalyst on Methylene Blue Degradation

In Water High Yield and Selectivity of CH<sub>4</sub> and H<sub>2</sub> Production Using UVC Light and a SiO<sub>2</sub>-surface-modified TiO<sub>2</sub> Photocatalysts

Photooxidation and Virus Inactivation using TiO2(P25)–SiO2 Coated PET Film

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