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Article

In Situ Etching Synthesis of TiO2-SBA-15 Nanocomposite Enhancing Adsorption and Photocatalytic Degradation

1
College of Chemistry and Environmental Science, Qujing Normal University, Qujing 655400, China
2
Department of Chemistry, Shanghai Normal University, Shanghai 200234, China
3
School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huaian 223300, China
*
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Catalysts 2022, 12(11), 1334; https://doi.org/10.3390/catal12111334
Submission received: 28 September 2022 / Revised: 18 October 2022 / Accepted: 28 October 2022 / Published: 1 November 2022
(This article belongs to the Special Issue Recent Progress of Catalysis in “Dual Carbon Targets”)

Abstract

:
The adsorption-enhancing TiO2-SBA-15 photocatalyst has been synthesized by an in situ etching displacement method, which possesses unique regular hexagonal pores and large specific surface area. The as-prepared TiO2-SBA-15 can effectively adsorb and increase the concentration of pollutants in the photocatalyst and collision likelihood with the photogenerated radicals, thus improving the efficiency of photocatalytic organic degradation. The structure and morphology have been characterized by N2 adsorption isotherms, X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and scanning electron microscopy (SEM). These characterizations confirm that TiF4 alcohol solution prefers to react with the internal surface of SBA-15 because of the Siphon effect. Fourier transform infrared (FTIR) spectra demonstrate that a Ti-O-Si bond formed after the reaction of TiF4 with SBA-15, which reveals a wonderful combination of TiO2 and SiO2 even at low temperatures. Through this function, the nanocomposite TiO2-SBA-15 could obviously improve the efficiency of photocatalytical removal of toluene in the gas phase.

1. Introduction

Photocatalysis is driven by light irradiation of the catalyst to produce photogenerated electrons and holes, and later generate hydroxyl radicals [1,2]. It has the wonderful advantage of using rich free solar light, so it shows good application potential in environmental purification, hydrogen production, green organic synthesis, solar cells, etc. [3,4,5,6,7,8,9,10]. However, the photogenerated electrons, holes, and hydroxyl radicals are easily quenched in photocatalysis process, which limits its applications [11,12]. SBA-15 (mesoporous silica molecular sieve, Santa Barbara Amorphous of number 15) is the substrate expected to modify this restriction, due to its large specific surface area, two-dimensional hexagonal arrangement, and uniform channel [13,14,15]. TiO2-SBA-15 nanocomposite could be synthesized by several methods such as one-pot hydrothermal, modified implantation, or sol-gel deposition [16,17,18]. These studies reveal that such mesoporous silica can obviously increase the surface area of the catalyst and improve the activity [19]. However, these composites need complex synthesis processes and calcination under high temperatures. Furthermore, some activity sites of these composites are blocked or diluted by the SiO2 frame. TiF4, which has been studied extensively by researchers, should be one of the materials to solve the problem, due to its titanium source and release of HF [20,21]. HF can in situ etch SiO2 easily, at which point the Ti atom replaces the Si atom space to give out TiO2 under low temperature. So, TiO2 could cover the SiO2 substrate and expose the TiO2 face. More advanced, it has a high combination of the TiO2 and SBA-15.
In this paper, TiO2-SBA-15 is prepared by an in situ etching reaction of TiF4 and SBA-15. Then, TiO2 materials grow on the surface of the SBA-15 pores and take the place of the SiO2 crystal lattice space under low temperature. TiO2-SBA-15 keeps the morphology of two-dimensional hexagonal arrangement and uniform channel, and has large specific surface area, which increases the local pollutant concentration around the photocatalyst to promote free radicals colliding efficiently the pollutants, and catalytic activity. This in situ etching synthesis method also ensures more exposure of TiO2 catalytic sites.

2. Results and Discussion

The HR-TEM morphologies reveal that both the SBA-15 and the 20%-TiO2-SBA-15 samples display a two-dimensional hexagonal arrangement and uniform channel. As shown in Figure 1a,c, the latter is less regular than the former. Compared to the SBA-15 sample in Figure 1b, the HR-TEM morphologies of 20%-TiO2-SBA-15 in Figure 1d further confirm that the order mesoporous pore has been damaged partially and the SBA-15 wall thickness has become narrower, from 4.9 nm to 4.2 nm. This occurs because the TiF4 ethanol solution enters the mesoporous pore structure during the evaporation process (the Siphon effect), then the TiF4 reacts with SBA-15 channel to generate TiO2 materials. This is further uncovered by the small-angle X-ray scattering (SAXS) results and pore size distribution.
Figure 2a,b shows the SEM images of SBA-15 and 20%-TiO2-SBA-15. It shows that the SBA-15 and 20%-TiO2-SBA-15 materials have a rod shape. After the in situ etching reaction, the morphology of 20%-TiO2-SBA-15 is not obviously changed, except a little rough area on the surface. As Figure 2c,d show, both SBA-15 and 20%-TiO2-SBA-15 contain a large amount of Si and O elements. Comparing to SBA-15, the 20%-TiO2-SBA-15 also contains Ti and F elements. The atomic percentage of Si, F and Ti is 19.75%, 16.2% and 2.21%, respectively. The large percentage of F element should be due to the enhancing adsorption for SiF4 on the surface of 20%-TiO2-SBA-15. After deducting this part of Si and F atoms according to the measurement ratio of SiF4, titanium dioxide accounts for 15.8% of the total mass ratio. This numeric value is close to the theoretical value of 20%, which reveals that the 20%-TiO2-SBA-15 was successfully synthesized as intended.
The wide-angle XRD (Figure 3a) shows peaks at 2 θ values of 24.8, 37.3, 47.6, 53.5, 55.1 and 62.2° reflections of anatase, which match the pattern of JCPDS Card no. 21-1272 [8]. As TiO2 amounts increase, the intensity of the peak grows first quickly then slowly, which should be due to mesoporous pores that limit its growth. Both TiO2-SBA-15 samples with wide peaks further confirm the small nanoparticle size, and the average crystallite size is 0.36 nm (calculated by Scherrer’s equation in the JADE 5.0 software) [22]. Usually, small-angle X-ray scattering (SAXS) shows the presence of an ordered arrangement of pores with strong intensity of a peak at low angle [23]. Figure 3b reveals an ordered 2D-hexagonal meso-structure because of well resolved (100), (110) and (200) reflections [24]. With increasing TiO2 content, the gradually decreasing peak intensity suggests a decreasing long-range order. The gradually right deviation peaks also reveal the reducing pore size of the channel, which is further confirmed by the pore size information listed in Table 1.
These materials display similar nitrogen sorption isotherms with narrow pore-size distributions centered at about 3.12–6.62 nm (Figure 4), which is typical for surfactant-templated mesoporous materials [25]. Detailed pore structure information is listed in Table 1. The pore volume and surface area are decreasing with increasing TiO2 content, which is due to the in situ chemical etching reaction of SiO2 and TiF4 to create TiO2 nanoparticles in their pore channels.
As Figure 5a shows, the binding energy peak at 533.1 eV should belong to O 1s of SBA-15. Spectrum of 20%-TiO2-SBA-15 appears to have a broad shoulder peak at 530.3 eV, which should belong to the O 1s of TiO2 [26,27]. After TiF4 in situ etching with SBA-15, the Si 2p binding energy slightly shifts 0.3 eV negative, due to the low electro-negativity of Titanium comparing to that of Silicon [28]. This demonstrates that large amounts of Ti atoms are so close enough to Si atoms that Ti could change the binding energy of Si.
The FTIR spectra (Figure 6) shows a broad absorbance peak in the range 3100 to 3450 cm−1 and a strong absorbance peak around 1630 cm−1, which should be attributed to the vibrations of the surface-adsorbed H2O and Ti-OH or Si-OH bonds. The broad peak at 1080 cm−1 should be attributed to vibration of Si-O-Si flame work [29]. Two new peaks characteristic of Ti-O-Ti and Ti=O bonds are also observed around 754 and 861 cm−1 after the TiF4 etching reaction [30,31]. Furthermore, a peak of around 960 cm−1 is observed, which belongs to Ti-O-Si according to references [32]. This observation confirms that strong bonding forms between TiO2 and SBA-15 without calcination. Referring to the decreasing pore size revealed by SAXS and N2 adsorption-desorption isotherms, it was revealed that TiF4 alcohol solution prefers to react with internal surface of SBA-15 due to the Siphon effect. So, the aiming unique structure is synthesized successfully to realize the combined absorption and photocatalysis to improve the efficiency of photogenerated OH•. Based on the above results, it is concluded that the formation of these nanocomposites involves an in situ etching reaction between TiF4 and SBA-15 (Figure 7).
Figure 8 confirms these unique nanocomposites show significantly improved photocatalytic activity. As shown in Figure 8, the conversion of toluene oxidation takes place by the mesoporous nanocomposites with different TiO2 loadings. When the reactions are conducted under dark conditions, the adsorption balance is observed at 2.0 h. As the TiO2 amount increased, the adsorption of toluene decreased from 34.9% to 26.3% (from 274.0 to 310.1 ppm), which should be attributed to the smaller surface area and the smaller mesoporous pore size. Under light irradiation, the removal ratio of toluene increases from 34.9% to 59.4%, when the content of TiO2 is increased from 0 to 20%. A near-twice improvement in toluene decomposition is achieved when 20% of TiO2 is loaded, unambiguously suggesting a significantly improved photocatalytic activity by the unique structure. However, further increase in TiO2 content leads to a decreasing catalytic activity, which should be attributed to the presence of a large number of TiO2 particles in pore channels, slowing down mass transport and reaction rate. In order to prove the wonderful performance of enhancing-adsorption, a 20%-TiO2-SBA-15 sample has been treated by hydrothermal method to destroy the structure but maintain the component. As Figure 9a shows, the untreated sample performed better than the treated sample in the adsorption and removal ratio of toluene, suggesting that enhancing-adsorption improves the pollutant concentration in the channel of 20%-TiO2-SBA-15 and the collision likelihood between hydroxyl radicals and toluene, promoting the photocatalytic reaction rate. The similar photocatalytic rate suggests that the hydrothermal method treatment only affects the adsorption structure of SBA-15 but not the performance of TiO2. P25 is regarded as a highly efficient photocatalyst as a commercial titanium dioxide material. Figure 9b reveals that 20%-TiO2-SBA-15 and 20%-P25-SBA-15 have similar a photodegradation rate, which demonstrates that the photocatalyst performs very good activity. However, 20%-P25-SBA-15 showed less adsorption ability, which should be due to the blocking of the channel of SBA-15 by P25 particles [33].
According to these characterizations and photocatalytic performance, TiO2-SBA-15 enhances adsorption and photocatalytic performance, because the enhanced absorption improves the concentration, as well as the collision likelihood of hydroxyl radicals and pollutants. As Figure 10 shows, TiO2-SBA-15 adsorbs toluene and increases the molecule amount in the inner channel. The hydroxyl radicals are produced under UV light irradiation on TiO2-SBA-15, which collides efficiently with the toluene inside the pore, then releases the produced CO2 and H2O.

3. Materials and Methods

3.1. Materials

Titanium tetrafluoride, surfactant P123 was purchased from Merck Ltd. (Shanghai, China); tetraethyl orthosilicate (TEOS), HCl and alcohol were purchased from Aladdin Reagent Co., Ltd. (Shanghai, China).

3.2. Preparation of TiO2-SBA-15 Series Catalysts

3.2.1. Preparation of SBA-15

SBA-15 was synthesized by using condensation of TEOS through prehydrolysis of TEOS according to the following procedure: First, a certain amount of TEOS (98%) was introduced into an aqueous solution containing 600 mL of 2.0 M HCl,152 mL of H2O and 20 g of P123. Then the TEOS was allowed to be prehydrolyzed for 60 min under vigorous stirring at 313 K. After being aged at 383 K for 24 h, the resulting white precipitate was filtrated and dried in a vacuum overnight. Finally, the surfactants and other organic substances in the samples were extracted and washed away by refluxing in ethanol solution for 24 h. The initial molar ratio in the mother solution was Si:HCl:H2O = 0.041:0.24:6.67, where Si refers to the total silica source. As-prepared sample was dried in a vacuum overnight at 353 K.

3.2.2. Preparation of TiO2-SBA-15 Samples

The TiO2-SBA-15 catalyst was prepared through the in situ etching of SBA-15 support with TiF4. In a typical synthesis, 1.0 g of the above SBA-15 was added into 15 mL of alcohol solution containing 0.387 g of TiF4, then the mixture was stirred for 1 h and then dried at room temperature for 12 h. Then it was dried under 373 K for 10 h to obtain 20%-TiO2-SBA-15. Other TiO2-SBA-15 series catalyst samples were obtained by adjusting TiF4 amount (0.0969 g, 0.194 g and 0.581 g), which were labeled as 5%-TiO2-SBA-15, 10%-TiO2-SBA-15, and 30%-TiO2-SBA-15, respectively. Here, the number before TiO2-SBA-15 is calculated by mTiO2/(mTiO2 + mSBA-15).

3.3. Catalyst Characterization

The XRD experiments were carried out on a Rigaku D/Max-RB diffractometer with Cu KR radiation. The TiO2 crystallite size was calculated by Scherrer’s equation in the JADE 5.0 software. HR-TEM studies were performed on a JEOL JEM2010 electron microscope, operated at an acceleration voltage of 200 kV. N2 adsorption isotherms were measured at 77 K with a Quantachrome Nova 4000 analyzer. The samples were measured after being outgassed at 423 K overnight. Pore size distributions were calculated by using the BJH model. The Brunauer–Emmett–Teller (BET) method was utilized to calculate the specific surface areas (SBET). FTIR spectra were collected with a Nicolet NEXUS 470 spectrometer by using the KBr method.

3.4. Activity Test

The 50 mg TiO2-SBA-15 photocatalyst was evenly tiled in a glass Petri dish, placed in the reactor (As shown in Figure 11), then sealed, and injected with 4 μL of toluene through the injection port. Each sample was adsorbed for 2.5 h in the dark, sampling every 30 min. The collector was directly connected with the reactor and gas chromatography for sampling easily. The toluene concentration was determined by gas chromatography. The power supply of xenon lamp (300 W, the distance between the light source and the catalyst) was turned on for photocatalytic performance experiments, and sampled every 60 min to determine the toluene concentration in the reaction tank. Before the degradation toluene experiment, the standard curves of different concentrations of toluene were plotted on the reaction tank to obtain the correspondence between the peak area of gas chromatography and the concentration of toluene. As reference, commercial Degussa P25 was mixed with SBA-15 by the same method of 20%-TiO2-SBA-15 except the TiF4. The activity test was also the same as 20%-TiO2-SBA-15.

4. Conclusions

Mesoporous TiO2-SBA-15 nanocomposites have been synthesized by in situ etching method. The as-prepared photocatalyst has a high surface area, well-defined 2D-hexagonal meso-structure and uniform channel. The TiO2 nanoparticles prefer to appear in the inner channel of SBA-15 due to the Siphon effect. The pore size and surface area decrease with increasing TiO2 content. TiO2-SBA-15 enhances adsorption and photocatalytic performance, because the enhancing-absorption improves the concentration of pollutant and the collision likelihood of hydroxyl radicals and pollutant, thus improving photocatalytic activity.

Author Contributions

Conceptualization and methodology, Z.B., F.Z., F.L. and Y.M.; writing—original draft preparation, F.L. and Y.M.; writing—review and editing, F.L., Y.M., D.Y., B.M., F.Z. and Z.B.; investigation and test, F.L., Y.M., D.Y. and B.M. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by Surface project of Yunnan Province science and technology Department, grant number 20210 A070001-050.

Acknowledgments

This work was supported by the Scientific and Technological Innovation Team for Green Catalysis and Energy Materialien Yunnan Institutions of Higher Learning.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Jo, W.K.; Kumar, S.; Isaacs, M.A.; Lee, A.F.; Karthikeyan, S. Cobalt promoted TiO2/GO for the photocatalytic degradation of oxytetracycline and congo red. Appl. Catal. B Environ. 2017, 201, 159–168. [Google Scholar] [CrossRef] [Green Version]
  2. Ohtani, B. Titania photocatalysis beyond recombination: A critical review. Catalysts 2013, 3, 942–953. [Google Scholar] [CrossRef] [Green Version]
  3. Kou, J.; Lu, C.; Wang, J.; Chen, Y.; Xu, Z.; Varma, R.S. Selectivity enhancement in heterogeneous photocatalytic transformations. Chem. Rev. 2017, 117, 1445–1514. [Google Scholar] [CrossRef] [Green Version]
  4. Cheng, Q.; Yuan, Y.J.; Tang, R.; Liu, Q.Y.; Bao, L.; Wang, P.; Zhong, J.; Zhao, Z.; Yu, Z.T.; Zou, Z. Rapid hydroxyl radical generation on (001)-facet-exposed ultrathin anatase TiO2 nanosheets for enhanced photocatalytic lignocellulose-to-H2 conversion. ACS Catal. 2022, 12, 2118–2125. [Google Scholar] [CrossRef]
  5. Abid, H.N.; Al-keisy, A.; Ahmed, D.S.; Salih, A.T.; Khammas, A. pH dependent synthesis and characterization of bismuth molybdate nanostructure for photocatalysis degradation of organic pollutants. Environ. Sci. Pollut. Res. 2022, 29, 37633–37643. [Google Scholar] [CrossRef] [PubMed]
  6. Zhang, L.; Lv, F.; Zhang, W.; Li, R.; Zhong, H.; Zhao, Y.; Zhang, Y.; Wang, X. Photo degradation of methyl orange by attapulgite–SnO2–TiO2 nanocomposites. J. Hazard. Mater. 2009, 171, 294–300. [Google Scholar] [CrossRef]
  7. Malik, A.; Hameed, S.; Siddiqui, M.J.; Haque, M.M.; Umar, K.; Khan, A.; Muneer, M. Electrical and optical properties of nickel- and molybdenum-doped titanium dioxide nanoparticle: Improved performance in dye-sensitized solar cells. J. Mater. Eng. Perform. 2014, 23, 3184–3192. [Google Scholar] [CrossRef]
  8. Mohamed, I.M.A.; Dao, V.D.; Yasin, A.S.; Barakat, N.A.M.; Choi, H.-S. Design of an efficient photoanode for dye-sensitized solar cells using electro-spun one-dimensional GO/N-doped nanocomposite SnO2/TiO2. Appl. Surf. Sci. 2017, 400, 355–364. [Google Scholar] [CrossRef]
  9. Colón, G. Towards the hydrogen production by photocatalysis. Appl. Catal. A Gen. 2016, 518, 48–59. [Google Scholar] [CrossRef]
  10. Marzo, L.; Pagire, S.K.; Reiser, O.; König, B. Visible-light photocatalysis: Does it make a difference in organic synthesis? Angew. Chem. Int. Ed. 2018, 57, 10034–10072. [Google Scholar] [CrossRef] [PubMed]
  11. Fang, J.; Fan, H.; Ma, Y.; Wang, Z.; Chang, Q. Surface defects control for ZnO nanorods synthesized by quenching and their anti-recombination in photocatalysis. Appl. Surf. Sci. 2015, 332, 47–54. [Google Scholar] [CrossRef]
  12. Shukla, P.; Fatimah, I.; Wang, S.; Ang, H.M.; Tadé, M.O. Photocatalytic generation of sulphate and hydroxyl radicals using zinc oxide under low-power UV to oxidise phenolic contaminants in wastewater. Catal. Today 2010, 157, 410–414. [Google Scholar] [CrossRef]
  13. Verma, P.; Kuwahara, Y.; Mori, K.; Raja, R.; Yamashita, H. Functionalized mesoporous SBA-15 silica: Recent trends and catalytic applications. Nanoscale 2020, 12, 11333–11363. [Google Scholar] [CrossRef]
  14. Bai, L.; Wang, S.; Wang, Z.; Hong, E.; Wang, Y.; Xia, C.; Wang, B. Kinetics and mechanism of photocatalytic degradation of methyl orange in water by mesoporous Nd-TiO2-SBA-15 nanocatalyst. Environ. Pollut. 2019, 248, 516–525. [Google Scholar] [CrossRef] [PubMed]
  15. Filip, M.; Petcu, G.; Anghel, E.M.; Petrescu, S.; Trica, B.; Osiceanu, P.; Stanica, N.; Atkinson, I.; Munteanu, C.; Mureseanu, M.; et al. FeTi-SBA-15 magnetic nanocomposites with photocatalytic properties. Catal. Today 2021, 366, 10–19. [Google Scholar] [CrossRef]
  16. Wei, J.Q.; Chen, X.J.; Wang, P.F.; Han, Y.B.; Xu, J.C.; Hong, B.; Jin, H.X.; Jin, D.F.; Peng, X.L.; Li, J.; et al. High surface area TiO2/SBA-15 nanocomposites: Synthesis, microstructure and adsorption-enhanced photocatalysis. Chem. Phys. 2018, 510, 47–53. [Google Scholar] [CrossRef]
  17. Yang, L.; Jiang, Z.; Lai, S.; Jiang, C.; Zhong, H. Synthesis of titanium containing SBA-15 and its application for photocatalytic degradation of phenol. Int. J. Chem. Eng. 2014, 2014, 691562. [Google Scholar] [CrossRef] [Green Version]
  18. Qian, X.F.; Kamegawa, T.; Mori, K.; Li, H.X.; Yamashita, H. Calcium phosphate coatings incorporated in mesoporous TiO2/SBA-15 by a facile inner-pore sol–gel process toward enhanced adsorption-photocatalysis performances. J. Phys. Chem. C 2013, 117, 19544–19551. [Google Scholar] [CrossRef]
  19. Gul, A.; Ullah, R.; Sun, J.; Munir, T.; Bai, S. Synthesis of mesoporous TiO2/BMMs via hydrothermal method and its potential application toward adsorption and photocatalytic degradation of crystal violet from aqueous solution. Arab. J. Chem. 2022, 15, 103530. [Google Scholar] [CrossRef]
  20. Kochkar, H.; Figueras, F. Synthesis of hydrophobic TiO2–SiO2 mixed oxides for the epoxidation of cyclohexene. J. Catal. 1997, 171, 420–430. [Google Scholar] [CrossRef]
  21. Ernst, E.M.; Church, B.C.; Gaddis, C.S.; Snyder, R.L.; Sandhage, K.H. Enhanced hydrothermal conversion of surfactant-modified diatom microshells into barium titanate replicas. J. Mater. Res. 2007, 22, 1121–1127. [Google Scholar] [CrossRef]
  22. Gnanaprakasam, A.; Sivakumar, V.M.; Sivayogavalli, P.L.; Thirumarimurugan, M. Characterization of TiO2 and ZnO nanoparticles and their applications in photocatalytic degradation of azodyes. Ecotoxicol. Environ. Saf. 2015, 121, 121–125. [Google Scholar] [CrossRef]
  23. Li, H.; Bian, Z.; Zhu, J.; Huo, Y.; Li, H.; Lu, Y. Mesoporous Au/TiO2 nanocomposites with enhanced photocatalytic activity. J. Am. Chem. Soc. 2007, 129, 4538–4539. [Google Scholar] [CrossRef] [PubMed]
  24. Li, H.; Zhang, F.; Wan, Y.; Lu, Y. Homoallylic alcohol isomerization in water over an immobilized Ru(II) organometallic catalyst with mesoporous structure. J. Phys. Chem. B 2006, 110, 22942–22946. [Google Scholar] [CrossRef]
  25. Kruk, M.; Jaroniec, M.; Ko, C.H.; Ryoo, R. Characterization of the porous structure of SBA-15. Chem. Mater. 2000, 12, 1961–1968. [Google Scholar] [CrossRef]
  26. Thunyaratchatanon, C.; Luengnaruemitchai, A.; Chaisuwan, T.; Chollacoop, N.; Chen, S.Y.; Yoshimura, Y. Synthesis and characterization of Zr incorporation into highly ordered mesostructured SBA-15 material and its performance for CO2 adsorption. Microporous Mesoporous Mater. 2017, 253, 18–28. [Google Scholar] [CrossRef]
  27. Luan, Z.; Maes, E.M.; van der Heide, P.A.W.; Zhao, D.; Czernuszewicz, R.S.; Kevan, L. Incorporation of titanium into mesoporous silica molecular sieve SBA-15. Chem. Mater. 1999, 11, 3680–3686. [Google Scholar] [CrossRef]
  28. Tandon, H.; Labarca, M.; Chakraborty, T. A scale of atomic electronegativity based on floating spherical gaussian orbital approach. Chem. Sel. 2021, 6, 5622–5627. [Google Scholar] [CrossRef]
  29. Elumalai, V.; Ganesh, T.; Selvakumar, C.; Sangeetha, D. Phosphonate ionic liquid immobilised SBA-15/SPEEK composite membranes for high temperature proton exchange membrane fuel cells. Mater. Sci. Energy Technol. 2018, 1, 196–204. [Google Scholar] [CrossRef]
  30. Téllez-Jurado, L.; Rubio, J.; Rubio, F.; Morales, E.; Oteo, J. Synthesis of inorganic-organic hybrid materials from TEOS, TBT and PDMS. J. Mater. Sci. 2003, 38, 1773–1780. [Google Scholar] [CrossRef]
  31. Kundu, R.S.; Dult, M.; Punia, R.; Parmar, R.; Kishore, N. Titanium induced structural modifications in bismuth silicate glasses. J. Mol. Struct. 2014, 1063, 77–82. [Google Scholar] [CrossRef]
  32. Huo, Y.; Zhang, Y.; Xu, W.; Tang, K.; Lu, X.; Ma, R.; Fu, Y.; Zhu, W. Acid-modulated synthesis of Ti-MWW zeolites with rich framework ti species for efficient epoxidation. Ind. Eng. Chem. Res. 2020, 59, 19929–19937. [Google Scholar] [CrossRef]
  33. Perathoner, S.; Lanzafame, P.; Passalacqua, R.; Centi, G.; Schlögl, R.; Su, D.S. Use of mesoporous SBA-15 for nanostructuring titania for photocatalytic applications. Microporous Mesoporous Mater. 2006, 90, 347–361. [Google Scholar] [CrossRef]
Figure 1. HR-TEM images of the SBA-15 and the 20%-TiO2-SBA-15 samples: (a,b) SBA-15 along with (100) and (001) directions, respectively; (c,d) 20%-TiO2-SBA-15 along with (100) and (001) directions, respectively.
Figure 1. HR-TEM images of the SBA-15 and the 20%-TiO2-SBA-15 samples: (a,b) SBA-15 along with (100) and (001) directions, respectively; (c,d) 20%-TiO2-SBA-15 along with (100) and (001) directions, respectively.
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Figure 2. SEM images of the SBA-15 and the 20%-TiO2-SBA-15 samples (a,b), (b) EDS-mapping of the SBA-15 and the 20%-TiO2-SBA-15 samples (c,d).
Figure 2. SEM images of the SBA-15 and the 20%-TiO2-SBA-15 samples (a,b), (b) EDS-mapping of the SBA-15 and the 20%-TiO2-SBA-15 samples (c,d).
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Figure 3. (a) XRD patterns of different TiO2 loading amounts, (b) SAXS plots of different TiO2 loading amounts.
Figure 3. (a) XRD patterns of different TiO2 loading amounts, (b) SAXS plots of different TiO2 loading amounts.
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Figure 4. (a) Pore size curves calculated from the BJH equivalent cylindrical model, (b) N2 adsorption-desorption isotherms.
Figure 4. (a) Pore size curves calculated from the BJH equivalent cylindrical model, (b) N2 adsorption-desorption isotherms.
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Figure 5. (a) O 1s XPS spectra of SBA-15 and 20%-TiO2-SBA-15, (b) Si 2p XPS spectra of SBA-15 and 20%-TiO2-SBA-15.
Figure 5. (a) O 1s XPS spectra of SBA-15 and 20%-TiO2-SBA-15, (b) Si 2p XPS spectra of SBA-15 and 20%-TiO2-SBA-15.
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Figure 6. (a) FT-IR spectra of SBA-15 and 20%-TiO2-SBA-15, (b) FT-IR spectra of 20%-TiO2-SBA-15 (wavenumber from 600–1000 cm−1) from circle marked in (a).
Figure 6. (a) FT-IR spectra of SBA-15 and 20%-TiO2-SBA-15, (b) FT-IR spectra of 20%-TiO2-SBA-15 (wavenumber from 600–1000 cm−1) from circle marked in (a).
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Figure 7. Schematic diagram of the in situ etching reaction of TiF4 and SBA-15.
Figure 7. Schematic diagram of the in situ etching reaction of TiF4 and SBA-15.
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Figure 8. The photocatalytic performance curve of different TiO2 loading catalysts degrading toluene, (a) concentration of toluene for removal process, (b) removal ratio of toluene for removal process.
Figure 8. The photocatalytic performance curve of different TiO2 loading catalysts degrading toluene, (a) concentration of toluene for removal process, (b) removal ratio of toluene for removal process.
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Figure 9. (a) The photocatalytic performance curve of 20%-TiO2-SBA-15 samples before and after hydrothermal treatment, (b) The photocatalytic performance of 20%-TiO2-SBA-15 and 20%-P25-SBA-15.
Figure 9. (a) The photocatalytic performance curve of 20%-TiO2-SBA-15 samples before and after hydrothermal treatment, (b) The photocatalytic performance of 20%-TiO2-SBA-15 and 20%-P25-SBA-15.
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Figure 10. Mechanism of TiO2-SBA-15 improves the pollutant concentration and the collision likelihood between hydroxyl radicals and Toluene.
Figure 10. Mechanism of TiO2-SBA-15 improves the pollutant concentration and the collision likelihood between hydroxyl radicals and Toluene.
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Figure 11. Schematic diagram of photocatalytic gas phase degradation of Toluene.
Figure 11. Schematic diagram of photocatalytic gas phase degradation of Toluene.
Catalysts 12 01334 g011
Table 1. Sample specific surface area and pore size for SBA-15 and different TiO2 loading amounts.
Table 1. Sample specific surface area and pore size for SBA-15 and different TiO2 loading amounts.
SamplesSBET/m2/gD/nmVpore/cc·g−1
SBA-15773.46.620.833
5%-TiO2-SBA-15681.25.400.801
10%-TiO2-SBA-15650.53.640.588
20%-TiO2-SBA-15628.93.520.526
30%-TiO2-SBA-15409.63.120.046
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Lv, F.; Miao, Y.; Yang, D.; Mao, B.; Bian, Z.; Zhu, F. In Situ Etching Synthesis of TiO2-SBA-15 Nanocomposite Enhancing Adsorption and Photocatalytic Degradation. Catalysts 2022, 12, 1334. https://doi.org/10.3390/catal12111334

AMA Style

Lv F, Miao Y, Yang D, Mao B, Bian Z, Zhu F. In Situ Etching Synthesis of TiO2-SBA-15 Nanocomposite Enhancing Adsorption and Photocatalytic Degradation. Catalysts. 2022; 12(11):1334. https://doi.org/10.3390/catal12111334

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Lv, Fujian, Yingchun Miao, Didi Yang, Bing Mao, Zhenfeng Bian, and Fengxia Zhu. 2022. "In Situ Etching Synthesis of TiO2-SBA-15 Nanocomposite Enhancing Adsorption and Photocatalytic Degradation" Catalysts 12, no. 11: 1334. https://doi.org/10.3390/catal12111334

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