Cosolvent-Induced Gelation and the Hydrothermal Enhancement of the Crystallinity of Titania−Silica Mixed Oxides for the Photocatalytic Remediation of Organic Pollutants

Kibombo, Harrison S.; Zhao, Dan; Gonshorowski, Andra; Budhi, Sridhar; Koppang, Miles D.; Koodali, Ranjit T.

doi:10.1021/jp110988j

Cited by 33 publications

(24 citation statements)

References 48 publications

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“…In method C, the formation of the titaniatropic mesophase is presumed to be relatively slower in comparison to method B. This is because pre-hydrolysis of titanium alkoxides in polar solvents such as ethanol promotes solvation as explained by us previously [42]. It seems that the titaniatropic mesophase undergoes reorganization through evaporation of the solvent as explained by us in a recent review [43].…”

Section: Physico-chemical Characterizationmentioning

confidence: 95%

Investigation of Room Temperature Synthesis of Titanium Dioxide Nanoclusters Dispersed on Cubic MCM-48 Mesoporous Materials

Budhi

Zhao

et al. 2015

Catalysts

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Titania containing cubic MCM-48 mesoporous materials were synthesized successfully at room temperature by a modified Stöber method. The integrity of the cubic mesoporous phase was retained even at relatively high loadings of titania. The TiO2-MCM-48 materials were extensively characterized by a variety of physico-chemical techniques. The physico-chemical characterization indicate that Ti 4+ ions can be substituted in framework tetrahedral positions. The relative amount of Ti 4+ ions in tetrahedral position was dependent on the order of addition of the precursor. Even at relatively high loadings of titania, no distinct bulk phase of titania could be observed indicating that the titania nanoclusters are well dispersed on the high surface area mesoporous material and probably exist as amorphous nanoclusters. The TiO2-MCM-48 materials were found to exhibit 100% selectivity in the cyclohexene oxidation at room temperature in the presence of tert-butylhydroperoxide (t-BHP) as the oxidant. The results suggest that room temperature synthesis is an attractive option for the preparation of TiO2-MCM-48 materials with interesting catalytic properties. OPEN ACCESSCatalysts 2015, 5 1604

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Section: Physico-chemical Characterizationmentioning

confidence: 95%

Investigation of Room Temperature Synthesis of Titanium Dioxide Nanoclusters Dispersed on Cubic MCM-48 Mesoporous Materials

Budhi

Zhao

et al. 2015

Catalysts

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“…The absorption peaks at about 1630 and 3430 cm −1 are attributed to the bending and stretching vibrations of surface water molecules. Finally, the bands at 470, 800, and 1096 cm −1 are associated with the Si-O-Si deformation pattern, and symmetric and asymmetric stretching vibration, respectively [13,18]. These bands are stronger in the R-TiO2/SiO2 sample than in the other two, indicating that the Si present in the aquatic plant leaves was introduced to the resulting TiO2/SiO2 composites.…”

Section: Components Structures and Morphologies Of Tio 2 /Sio 2 Phomentioning

confidence: 96%

“…These bands are stronger in the R-TiO 2 /SiO 2 sample than in the other two, indicating that the Si present in the aquatic plant leaves was introduced to the resulting TiO 2 /SiO 2 composites. In particular, a very weak band at 952 cm −1 due to Ti-O-Si linkage could be found in the R-TiO 2 /SiO 2 sample, further suggesting that the SiO 2 was bonded to the TiO 2 particles [13,19,20]. The peak intensity of Ti-O-Si and Si-O-Si becomes less pronounced in WH-TiO 2 /SiO 2 and D-TiO 2 /SiO 2 , probably because the low level of SiO 2 is difficult to detect using FTIR.…”

Section: Components Structures and Morphologies Of Tio 2 /Sio 2 Phomentioning

confidence: 97%

“…There are no diffraction peaks of silica or silicates in the XRD patterns, which indicates that the silica structure in the TiO 2 /SiO 2 composite, just as in the original plant leaves, is still amorphous. It has been reported that SiO 2 particles in TiO 2 grain boundaries are able to inhibit the formation of rutile by restricting the atomic rearrangement during the phase transformation [12,13,17]. Thus, the enhanced Table 1).…”

Section: Components Structures and Morphologies Of Tio 2 /Sio 2 Phomentioning

confidence: 99%

“…As known, the biomorphic mesoporous structure is believed to improve the specific surface area of TiO 2 . Besides, it is frequently reported that the introduction of SiO 2 is also capable of increasing the specific surface area of TiO 2 photocatalysts [12,13]. As a result, TiO 2 /SiO 2 photocatalysts could provide more adsorption and active sites, and quicken the diffusion and transition of reactants in the photocatalytic process, ultimately benefiting the increase of photocatalytic efficiency [6,7].…”

Section: Components Structures and Morphologies Of Tio 2 /Sio 2 Phomentioning

confidence: 99%

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Biotemplated Mesoporous TiO2/SiO2 Composite Derived from Aquatic Plant Leaves for Efficient Dye Degradation

Yan

Guo

et al. 2017

Catalysts

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Abstract:The biotemplating technique is an environmental-protective high-efficiency new technology by which the resulting TiO 2 may simultaneously attain the duplication of structure and self-doping elements from biotemplate materials, which is highly desirable for photocatalytic applications. In this paper, aquatic plant leaves-including reed, water hyacinth, and duckweed-were used as both templates and silicon precursors to successfully synthesize biomorphic TiO 2 /SiO 2 composite with mesoporous structures. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N 2 adsorption-desorption, and UV-visible diffuse reflectance spectra were applied to characterize the microstructures of the samples. The results show that all TiO 2 /SiO 2 composites are mainly composed of an anatase phase with mesoporous structure and possess high specific surface area. Compared with commercial Degussa P25 TiO 2 , all TiO 2 /SiO 2 samples display intensive light-harvesting efficiency, particularly in the visible light range. The activities were evaluated by using gentian violet as a target for photocatalytic degradation experiments under simulated solar irradiation. The TiO 2 /SiO 2 samples templated by reed and water hyacinth leaves exhibit high activity, while the TiO 2 /SiO 2 samples obtained from duckweed are inferior to P25 in the degradation of gentian violet. A synergistic effect of SiO 2 incorporation and structural construction through biotemplating is proposed to be beneficial to photocatalytic activity.

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Precise Size Control over Ultrafine Rutile Titania Nanocrystallites in Hierarchical Nanotubular Silica/Titania Hybrids with Efficient Photocatalytic Activity

Huang

2013

Chemistry A European J

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Hierarchical-structured nanotubular silica/titania hybrids incorporated with particle-size-controllable ultrafine rutile titania nanocrystallites were realized by deposition of ultrathin titania sandwiched silica gel films onto each nanofiber of natural cellulose substances (e.g., common commercial filter paper) and subsequent flame burning in air. The rapid flame burning transforms the initially amorphous titania into rutile phase titania, and the silica gel films suppress the crystallite growth of rutile titania, thereby achieving nano-precise size regulation of ultrafine rutile titania nanocrystallites densely embedded in the silica films of the nanotubes. The average diameters of these nanocrystallites are adjustable in a range of approximately 3.3-16.0 nm by a crystallite size increment rate of about 2.4 nm per titania deposition cycle. The silica films transfer the electrons activated by crystalline titania and generate catalytic reactive species at the outer surface. The size-tuned ultrafine rutile titania nanocrystallites distributed in the unique hierarchical networks significantly improve the photocatalytic performance of the rutile phase titania, thereby enabling a highly efficient photocatalytic degradation of the methylene blue dye under ultraviolet light irradiation, which is even superior to the pure anatase-titania-based materials. The facile stepwise size control of the rutile titania crystallites described here opens an effective pathway for the design and preparation of fine-nanostructured rutile phase titania materials to explore potential applications.

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Cosolvent-Induced Gelation and the Hydrothermal Enhancement of the Crystallinity of Titania−Silica Mixed Oxides for the Photocatalytic Remediation of Organic Pollutants

Cited by 33 publications

References 48 publications

Investigation of Room Temperature Synthesis of Titanium Dioxide Nanoclusters Dispersed on Cubic MCM-48 Mesoporous Materials

Investigation of Room Temperature Synthesis of Titanium Dioxide Nanoclusters Dispersed on Cubic MCM-48 Mesoporous Materials

Biotemplated Mesoporous TiO2/SiO2 Composite Derived from Aquatic Plant Leaves for Efficient Dye Degradation

Precise Size Control over Ultrafine Rutile Titania Nanocrystallites in Hierarchical Nanotubular Silica/Titania Hybrids with Efficient Photocatalytic Activity

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