Home High-temperature treated TiO2 modified with 3-aminopropyltriethoxysilane as photoactive nanomaterials
Article Open Access

High-temperature treated TiO2 modified with 3-aminopropyltriethoxysilane as photoactive nanomaterials

  • Agnieszka Sienkiewicz , Ewelina Kusiak-Nejman EMAIL logo , Agnieszka Wanag EMAIL logo , Konstantinos Aidinis , Danuta Piwowarska , Antoni W. Morawski and Niko Guskos
Published/Copyright: October 12, 2022
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
REVIEWS ON ADVANCED MATERIALS SCIENCE
From the journal REVIEWS ON ADVANCED MATERIALS SCIENCE Volume 61 Issue 1

Abstract

A series of titanium dioxide (TiO2) modified with 3-aminopropyltriethoxysilane (APTES) was prepared by high-temperature calcination in an argon atmosphere in the temperature range from 800 to 1,000°C. The properties of the obtained samples were compared with those of pure TiO2 annealed under the same conditions. Examining electron paramagnetic resonance (EPR) parameters at room temperature for APTES–TiO2 showed an intense resonance line from defects related to conducting electrons with g eff from 2.0028 to 2.0026 and 1.9052 for temperatures 800, 900, and 1,000°C, respectively, while for pure calcined TiO2, these ERP lines were not observed. With the increase in the calcination temperature to 900°C for APTES–TiO2 samples, the EPR increases linearly. This has been combined with a relatively high anatase content and small crystallites. The EPR line intensity at RT calculated for 1 g of sample showed an almost linear relationship with the photoactivity in removing ORANGE II dyes from water.

Keywords: APTES-modified TiO; photoactivity; EPR measurements

1 Introduction

Titanium dioxide (TiO2), a wide band gap inorganic semiconductor (3.23 eV for the most active anatase phase), is a fascinating material from the perspective of both pure theoretical science and industrial use [1]. Its extensive application in various fields, particularly in heterogeneous photocatalysis [2,3,4]. Because TiO2 is an inexpensive, stable, and non-toxic material, the significant efforts made over the past decades in the synthesis of modified TiO2 have provided nanomaterials with new properties and applications with greatly enhanced performance [5,6,7,8].

Modified TiO2 has been and continues to be studied by magnetic resonance for years [9,10,11,12]. Electron paramagnetic resonance (EPR) is a spectroscopic method frequently utilized to investigate the structure and interactions of paramagnetic entities like transition metal ions, free radicals, and defects in solids such as electrons trapped in lattice vacancies [13]. These defects are important for the TiO2 photocatalytic properties [13,14]. Information from the EPR study supplements data from other characterization methods and gives a more detailed picture of the surface and interfacial electron transfer processes [14]. In TiO2-based photocatalysts, the photogenerated charges like electrons (e−) and holes (h+) have sufficiently distinct structures and electron configurations to enable the spectral resolution of each species. Additionally, the structural diversity between anatase and rutile phases makes it possible to observe electrons trapped in each of the two TiO2 polymorphous forms. Such sensitivity to the structural geometry of the trapping sites results in EPR being a beneficial technique for studying electron transfer processes in photocatalysts [14,15] and confirming the paramagnetic reactive species formation in studied materials [16,17]. It is a fairly known fact that silicon and its oxides can significantly modify the surface of TiO2. For example, the pronounced reversible surface change of the hydrophilic-to-hydrophobic for TiO2/Si coatings is described [18]. Recently, the narrow EPR signal intensity with the temperature decrease is observed. This effect is explained by the Anderson localization of conduction electrons in the defected crystalline structure of rGO [19].

In our previous studies, a series of materials based on TiO2 modified with 3-aminopropyltriethoxysilane (APTES) with improved photocatalytic activity under artificial solar light (ASL) irradiation were successfully synthesized [20]. The new photocatalysts were prepared in a two-step process by a 4-hour solvothermal functionalization in a pressure autoclave at 180°C and calcination in an argon atmosphere in the temperature range from 800 to 1,000°C, where the modifier concentrations were 100, 500 and 1,000 mM. The presence of APTES after modification was confirmed via FT-IR/DRS measurements and the EDX mapping and N, C, and Si content analysis. It was reported that the presence of carbon and silicon in the APTES/TiO2 samples contributed to an effective delay in the phase transformation of the anatase to rutile, the increase in crystallite size (during annealing) affected the decrease in specific surface area. The efficiency of the prepared materials was studied during the methylene blue (MB) decomposition under ASL irradiation. The calcination enhanced the ASL-driven photocatalytic activity of all APTES-modified TiO2. It was noted that the highest dye decomposition degree was obtained for materials annealed at 900°C. Moreover, considering the highest performance and economic aspects, TiO2–4 h–180°C–500 mM–Ar–900°C was found to be the most prospective nanomaterial. The most important conclusion was the experimental finding that in the modified APTES/TiO2 samples during calcination to 900°C, the anatase phase is still present in an amount of up to 96% with crystallite size of 30 nm, while the rutile phase with crystallite size of 55 nm occurred with a slight increase of about 6% [20].

In the present study, we extended our previous work and, for the first time, used EPR to study the magnetic properties of a selected series of APTES/TiO2 nanomaterials functionalized with 500 mM of modifier annealed in an argon atmosphere. The photocatalysts modified with 500 mM of APTES were chosen for EPR studies because they exhibited higher photoactivity than the materials functionalized with 100 and 1,000 mM concentrations. To the best of our knowledge, this is the first publication presenting results from EPR studies of APTES-modified TiO2 photocatalysts heated at high temperatures, which have photoactivity in the ASL range. Furthermore, in this article, we also extended our previous studies by adding activity results for Orange II under both ultraviolet (UV) light and ASL irradiation. EPR measurements were made at room temperature because photocatalytic activation was performed at this temperature.

It is interesting to compare the formation of magnetic moments and their intensity concerning the photoactivity and determine whether they increase photoactivity in the TiO2 samples modified with APTES after calcination.

2 Experimental

The crude TiO2 slurry, provided by the chemical plant Grupa Azoty Zakłady Chemiczne “Police” S.A. (Police, Poland), was used as a TiO2 starting material. APTES utilized as a silicon precursor was purchased from Merck KGaA (Darmstadt, Germany). Ethanol from P.P.H. “STANLAB” Sp.J., (96%, Poland) was used as a solvent of APTES. Orange II (C16H11N2NaO4S, ≥85%, Firma Chempur®, Poland) was used as a model for organic water pollution. The APTES-modified TiO2 nanomaterials were obtained using the solvothermal method and calcination process. The concentration of the APTES in ethanol was 500 mM. The samples were calcined at 800, 900, and 1,000°C for 4 h in Ar atmosphere (60 mL·min−1, purity of 5.0, and Messer Polska Sp. z o.o., Poland). The procedure is described in detail in our previous publication [20].

2.1 Photocatalytic activity measurements

The Orange II decomposition processes under ASL irradiation with the intensity of 837 W·m−2 for 300–2,800 nm and 0.3 W·m−2 for the 280–400 nm regions as well as under UV–Vis light irradiation, with the radiation intensity of 65 W·m−2 for 300–2,800 nm and 36 W·m−2 for the 280–400 nm region, were carried out to determine the photoactivity of the prepared materials. The experiments were conducted in a glass beaker using 0.5 L of dye solution with an initial concentration of 5 mg·L−1 and 0.5 g·L−1 of the appropriate photocatalyst. Before irradiation, adsorption measurements were performed in light-free conditions for 60 min to establish the adsorption–desorption equilibrium at the photocatalyst–dye interface. After that, the suspension was subjected to ASL radiation. The Orange II concentration was analyzed every 60 minutes using the V-630 UV–Vis spectrometer (JASCO International Co., Japan). The obtained activity results were converted as the mass of MB or Orange II removed per 1 g of photocatalyst.

3 Results and discussion

Several new characteristic bands from APTES were noted in the spectra presented in Figure 1, indicating that the synthesis of the new nanomaterials method was carried out successfully. These bands are located at about 2,920, 2,881, 1,536, 1,363, 1,155, and 1,070 cm−1 and assigned to the symmetric and asymmetric stretching vibration of alkyl groups, the asymmetric − NH 3 + deformation modes, C−N bonds Si−O−Si stretching vibrations, and Si–O–C stretching mode, respectively. The stretching vibrations of Ti–O–Si bonds are observed between 950 and 910 cm−1. However, the band at 910 cm−1 is related to the condensation reaction that occurred between silanol and surface –OH groups [20]. It should be noted that after calcination, some characteristic bands for APTES such as alkyl groups, − NH 3 + and C–N bonds did not present. The reason for this was the non-permanent bond between these groups and the TiO2 surface. The presence of APTES on the TiO2 surface, and thus, the effectiveness of the modification was confirmed also by nitrogen and carbon analysis and EDX mapping presented in our previous article [20]. It was found that the addition of silicon and carbon in APTES/TiO2 samples effectively delayed the anatase-to-rutile phase transformation and the increase in crystallite size of both TiO2 polymorphous forms during high-temperature annealing. Therefore, the calcined APTES-functionalized TiO2 showed higher specific surface area and pore volume values than the reference materials (Table 1). Furthermore, the modified TiO2 surface charge change from positive to negative after calcination enhanced the dye adsorption degree [20]. EDS measurements show that silicon content fluctuates around 2% for all calcined samples by mass with carbon content from 0.17 to 0.08 and 0.03 wt% for temperatures 800, 900, and 1,000°C, respectively.

Figure 1 Diffuse reflectance Fourier transform infrared spectra of APTES/TiO2 nanomaterials [20].
Figure 1

Diffuse reflectance Fourier transform infrared spectra of APTES/TiO2 nanomaterials [20].

Table 1

Physicochemical properties of starting-TiO2, reference samples, and APTES-modified TiO2 nanomaterials [20]

Sample name S BET (m2·g−1) V total (cm3·g−1) Anatase in crystallite phase (%) Anatase crystallite size (nm) Rutile in crystallite phase (%) Rutile crystallite size (nm) Zeta potential δ (mV)
TiO2–Ar–800°C 6 0.020 1 >100 99 >100 −35.9
TiO2–Ar–900°C 3 0.008 — — 100 >100 −36.7
TiO2–Ar–1,000°C 4 0.009 — — 100 >100 −41.3
TiO2–4 h–180°C–500 mM 124 0.162 96 15 4 48 +22.8
TiO2–4 h–180°C–500 mM–800°C 95 0.221 96 20 4 58 −47.4
TiO2–4 h–180°C–500 mM–900°C 46 0.192 94 30 6 55 −51.0
TiO2–4 h–180°C–500 mM–1000°C 16 0.069 12 47 88 >100 −41.3

For pure starting-TiO2 samples calcined only in argon at 800, 900, and 1,000°C and without APTES modification (TiO2–Ar–800°C, TiO2–Ar–900°C, and TiO2–Ar–1000°C, that contain only rutile with crystallites above 100 nm [20]), the spectral spectra measurements did not show any EPR signal at RT in the investigated measuring range.

Contrary to the above-mentioned samples, during calcination in argon at 800, 900, and 1,000°C with APTES modification (TiO2–4 h–180°C–500 mM–800°C, TiO2–4 h–180°C–500 mM–900°C, and TiO2–4 h–180°C–500 mM–1000°C), an intense symmetrical resonance line appeared. In Figure 2 are given experimental EPR spectra measured at RT compared to the uncalcined TiO2–4 h–180°C–500 mM material. For EPR parameters, calculation spectra have been collected, as shown in Figure 3.

Figure 2 EPR spectra measured at RT of the uncalcined TiO2–4 h–180°C–500 mM, and annealed TiO2–4 h–180°C–500 mM–800°C, TiO2–4 h–180°C–500 mM–900°C, and TiO2–4 h–180°C–500 mM–1000°C. The spectra are rescaled to a unit mass.
Figure 2

EPR spectra measured at RT of the uncalcined TiO2–4 h–180°C–500 mM, and annealed TiO2–4 h–180°C–500 mM–800°C, TiO2–4 h–180°C–500 mM–900°C, and TiO2–4 h–180°C–500 mM–1000°C. The spectra are rescaled to a unit mass.

Figure 3 EPR spectra at RT of the uncalcined TiO2–4 h–180°C–500 mM, and annealed TiO2–4 h–180°C–500 mM–800°C, TiO2–4 h–180°C–500 mM–900°C and TiO2–4 h–180°C–500 mM–1000°C with their simulations.
Figure 3

EPR spectra at RT of the uncalcined TiO2–4 h–180°C–500 mM, and annealed TiO2–4 h–180°C–500 mM–800°C, TiO2–4 h–180°C–500 mM–900°C and TiO2–4 h–180°C–500 mM–1000°C with their simulations.

The EPR parameters: effective g-factor (g eff), peak-to-peak linewidth ΔBpp, and integrated intensity I int can be calculated from the magnetic resonance condition: hν = g eff μ B B r where h is Planck constant, ν – the microwave frequency, μ B – Bohr magneton, and B r magnetic resonance field. The integrated intensity, proportional to the magnetic susceptibility on microwave frequency of a spin system producing EPR spectrum, is defined as I int = A·ΔBpp where A is signal amplitude. At high temperatures, the width of the resonance lines decreases significantly with a change in calcination temperature. So that the relaxation processes depend on the temperature of calcination, as given in Table 2.

Table 2

EPR parameters for measurements at RT for studied samples

EPR Parameters A (a.u.) ΔBpp (mT) I int (mT2) g eff
TiO2–4 h–180°C–500 mM–800°C 870242.5406 0.28770 7.2031 × 104 2.0028
TiO2–4 h–180°C–500 mM–900°C 622752.3100 0.28086 4.9124 × 104 2.0026
TiO2–4 h–180°C–500 mM–1000°C 150861.3207 0.30198 1.3757 × 104 1.9052

According to the data listed in Table 2, all parameters (effective g-factor (g eff), signal amplitude A, and integrated intensity I int) decrease with increased temperature from 800 to 1,000°C, whereas peak-to-peak linewidth ΔBpp shows independent changes from temperature with their fittings by Lorentzian function.

A step-by-step change in the g eff value of the parameter for a nanocomposite calcined at temperatures of 800–1,000°C may be caused by a change in the resonance condition by forming an additional internal magnetic field. It can be formed by the resulting magnetic agglomerates, reducing its intensity. Observed diminishing energy gape E g from 3.27 eV to 3.21 and 3.02 confirm changes of electron behavior [20].

These EPR parameters at the temperatures of 800, 900, and 1,000°C correlate well with the corresponding decrease in the content of anatase from 94 to 12 wt% and the increase in the size of their crystallites from 20 through 30 to 47 nm. An increase in the rutile content from 4 to 88 wt% and an increase in the size of rutile crystallites from 58 to over 100 nm, at appropriate temperatures [20], were also noticed.

Additionally, the observed EPR signal has recently been associated with conduction electrons [21] but a similar signal also occurs from oxygen defects. Both are related to electron transfer. High calcination temperatures can significantly improve photocatalytic properties. In both cases, electron transfer plays an important role. In the first case, at room temperature, the EPR signal is more intense. Rather, this signal comes from the total area of the nanocomposite. Surface effects also play an important role in photocatalytic processes.

Table 3 summarizes the obtained intensities of calcined samples with and without APTES addition, converted to 1 g of photocatalyst. As can be seen, the samples without modifier showed no EPR signal, while the samples supplemented with APTES exhibited intense EPR at RT lines. The calcined samples without the addition of silicon showing no EPR lineage were also photocatalytically inactive, except for the degradation of the Orange II dye in the UV range, where small activities were recorded. Therefore, the EPR lines and the photocatalytic activities of these samples in the scope of UV and ASL radiation during the degradation of dyes, Orange II, are summarized in Table 4.

Table 3

Summary of the EPR signal intensity in studied samples per 1 g

Sample name EPR intensity line/1 g of photocatalyst
TiO2–Ar–800°C 0
TiO2–Ar–900°C 0
TiO2–Ar–1000°C 0
TiO2–4 h–180°C–500 mM 0
TiO2–4 h–180°C–500 mM–800°C 65,796
TiO2–4 h–180°C–500 mM–900°C 46,632
TiO2–4 h–180°C–500 mM–1000°C 13,922
Table 4

Summary of photoactivity for Orange II decomposition under UV and ASL radiations and the intensity of the EPR signal line per gram of calcined APTES/TiO2 photocatalysts

Sample name Amount of removed dye after 360 min of ASL irradiation (mg of Orange II/1 g of photocatalyst) Amount of removed dye after 180 min of UV irradiation (mg of Orange II/1 g of photocatalyst) EPR intensity line/1 g of photocatalyst
TiO2–4 h–180°C–500 mM 0.0 0.0 0
TiO2–4 h–180°C–500 mM–800°C 1.7 28.2 65,796
TiO2–4 h–180°C–500 mM–900°C 1.2 25.8 46,632
TiO2–4 h–180°C–500 mM–1000°C 0.2 6.3 13,922

For Orange II, these samples, without APTES modification and calcination, showed no activity in both UV and ASL ranges.

It can be seen that the intensity of the photocatalytic decomposition of the Orange II dye, both in UV and in ASL radiation (Figures 4 and 5), is linearly related to the intensity of the EPR at the RT line signal, with the highest activity and intensity of the EPR line achieved by the sample calcined at 800°C.

Figure 4 Correlation between the amount of Orange II dye removed after 180 min of UV irradiation and EPR line intensity for APTES/TiO2 nanomaterials.
Figure 4

Correlation between the amount of Orange II dye removed after 180 min of UV irradiation and EPR line intensity for APTES/TiO2 nanomaterials.

Figure 5 Correlation between the amount of Orange II dye removed after 360 min of ASL irradiation and EPR line intensity for APTES/TiO2 nanomaterials.
Figure 5

Correlation between the amount of Orange II dye removed after 360 min of ASL irradiation and EPR line intensity for APTES/TiO2 nanomaterials.

It was mentioned earlier that the obtained partially reduced graphene oxide (prGO) has EPR spectra on the broad and narrow lines [22]. The resonance line was attributed to the conduction electrons. A similar resonance line was obtained in the samples discussed herein, with a more intense one for the nanocomposite modifications of APTES–TiO2.

It is well known the importance of electron transfer, especially in the temperature range above 650–700°C, as they cause significant changes in modified TiO2 nanocomposites photocatalytic processes. With the right concentration of conduction electrons, maximum photocatalytic efficiency is obtained. In the modified APTES–TiO2, it was possible to obtain larger active surfaces [20]. Hence, at room temperature, we have found more localized magnetic defects informing about the increase in conduction electrons similar to postulated for hydrothermally reduced graphene oxide [19].

4 Conclusions

Modified APTES–TiO2 nanocomposites after calcination in an argon atmosphere at temperatures 800, 900, and 1,000°C showed changes within many properties compared to pure calcined TiO2 that strongly depend on the temperature of annealing. New EPR lines appeared in calcined APTES–TiO2 materials, whereas these lines were absent for pure TiO2. EPR studies at room temperature for calcined APTES–TiO2 have shown the formation of a high concentration of defects associated with conduction electrons that strongly depend on the calcination temperature – g eff decreased from 2.0028 to 2.0026 and 1.9052 for 800, 900, and 1,000°C, respectively. At an annealing temperature of 1,000°C, concentration decreases significantly. It is probably the result of the formation of magnetic agglomerates. The EPR line intensity at RT calculated for 1 g of sample showed an almost linear relationship with the photoactivity in removing Orange II dyes from water.

Acknowledgment

This work was supported by grant 2017/27/B/ST8/02007 from the National Science Centre, Poland.

  1. Funding Information: This research was funded by the grant 2017/27/B/ST8/02007 from the National Science Centre, Poland.

  2. Author contributions: A. Sienkiewicz, A. Wanag, E. Kusiak-Nejman: methodology, conceptualization, writing − original draft, K. Aidinis: software, validation. D. Piwowarska: EPR measurements and their development, A.W. Morawski: visualization, conceptualization, writing − original draft, supervision, funding acquisition, N. Guskos: visualization, conceptualization, writing − original draft, supervision.

  3. Conflict of interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this study.

  4. Data availability statement: All data generated or analyzed during this study are included in this published article or are available from the corresponding author on reasonable request.

References

[1] Wan, L., J. F. Li, J. Y. Feng, W. Sun, and Z. Q. Mao. Anatase TiO2 films with 2.2eV band gap prepared by micro-arc oxidation. Materials Science and Engineering: B, Vol. 139, 2007, pp. 216–220.10.1016/j.mseb.2007.02.014Search in Google Scholar

[2] He, J., A. Kumar, M. Khan, and I. M. C. Lo. Critical review of photocatalytic disinfection of bacteria: from noble metals- and carbon nanomaterials-TiO2 composites to challenges of water characteristics and strategic solutions. Science of the Total Environment, Vol. 758, 2021, id. 143953.10.1016/j.scitotenv.2020.143953Search in Google Scholar PubMed

[3] Jiang, D., T. A. Otitoju, Y. Ouyang, N. F. Shoparwe, S. Wang, A. Zhang, and S. Li. A review on metal ions modified TiO2 for photocatalytic degradation of organic pollutants. Catalysts, Vol. 11, 2021, id. 1039.10.3390/catal11091039Search in Google Scholar

[4] Li, Z., Z. Li, C. Zuo, and X. Fang. Application of nanostructured TiO2 in UV photodetectors: A review. Advanced Materials, Vol. 34, No. 28, 2022, id. 2109083.10.1002/adma.202109083Search in Google Scholar PubMed

[5] Hou, X., K. Aitola, and P. D. Lund. TiO2 nanotubes for dye-sensitized solar cells – A review. Energy Science & Engineering, Vol. 9, 2021, pp. 921–937.10.1002/ese3.831Search in Google Scholar

[6] Al Zoubi, W., A. A. S. Al-Hamdani, S. Sunghun, and Y. G. Ko. A review on TiO2-based composites for superior photocatalytic activity. Reviews in Inorganic Chemistry, Vol. 41, No. 4, 2021, pp. 213–222.10.1515/revic-2020-0025Search in Google Scholar

[7] Maheswari, P., S. Harish, M. Navaneethan, C. Muthamizhchelvan, S. Ponnusamy, and Y. Hayakawa. Bio-modified TiO2 nanoparticles with Withania somnifera, Eclipta prostrata and Glycyrrhiza glabra for anticancer and antibacterial applications. Materials Science and Engineering: C, Vol. 108, 2020, id. 110457.10.1016/j.msec.2019.110457Search in Google Scholar PubMed

[8] Sienkiewicz, A., A. Wanag, E. Kusiak-Nejman, E. Ekiert, P. Rokicka-Konieczna, and A. W. Morawski. Effect of calcination on the photocatalytic activity and stability of TiO2 photocatalysts modified with APTES. Journal of Environmental Chemical Engineering, Vol. 9, 2021, id. 104794.10.1016/j.jece.2020.104794Search in Google Scholar

[9] Coronado, J. M., A. J. Maira, L. C. Conesa, K. L. Yeung, V. Augugliaro, and J. Soria. EPR study of the surface characteristics of nanostructured TiO2 under UV irradiation. Langmuir, Vol. 17, 2001, pp. 5368–5374.10.1021/la010153fSearch in Google Scholar

[10] Kumar, C. P., N. O. Gopal, T. C. Wang, M. S. Wong, and S. C. Ke. EPR investigation of TiO2 nanoparticles with temperature-dependent properties. The Journal of Physical Chemistry B, Vol. 110, 2006, pp. 5223–5229.10.1021/jp057053tSearch in Google Scholar PubMed

[11] Dimitrijevic, N. M., Z. V. Saponjic, B. M. Rabatic, O. G. Poluektov, and T. Rajh. Effect of size and shape of nanocrystalline TiO2 on photogenerated charges. An EPR study. The Journal of Physical Chemistry C, Vol. 111, No. 40, 2007, pp. 14597–14601.10.1021/jp0756395Search in Google Scholar

[12] Konovalova, T. A., L. D. Kispert, and V. V. Konovalov. Surface modification of TiO2 nanoparticles with carotenoids. EPR study. The Journal of Physical Chemistry B, Vol. 103, 1999, pp. 4672–4677.10.1021/jp9900638Search in Google Scholar

[13] Typek, J., N. Guskos, G. Zolnierkiewicz, M. Pilarska, A. Guskos, E. Kusiak-Nejman, and A.W. Morawski. Magnetic properties of TiO2/graphitic carbon nanocomposites. Reviews on Advanced Materials Science, Vol. 58, 2019, pp. 107–122.10.1515/rams-2019-0009Search in Google Scholar

[14] Hurum, D. C., A. G. Agrios, S. E. Crist, K. A. Gray, T. Rajh, and M. C. Thurnauer. Probing reaction mechanisms in mixed phase TiO2 by EPR. Journal of Electron Spectroscopy and Related Phenomena, Vol. 500, 2006, pp. 155–163.10.1016/j.elspec.2005.01.294Search in Google Scholar

[15] Dvoranová, D., M. Mazúr, I. Papailias, T. Giannakopoulou, C. Trapalis, and V. Brezová. EPR investigations of G-C3N4/TiO2 nanocomposites. Catalysts, Vol. 8, 2018, id. 47.10.3390/catal8020047Search in Google Scholar

[16] Barbierikova, Z., D. Dvoranova, V. Brezova, E. Dzunuzowic, D. N. Sredojevc, V. Lazic, and J.M. Nedeljkovic. Visible-light-responsive surface-modified TiO2 powder with 4-chlorophenol: A combined experimental and DFT study. Optical Materials, Vol. 89, 2019, pp. 237–242.10.1016/j.optmat.2019.01.027Search in Google Scholar

[17] Barierkova, Z., E. Plizingrova, M. Motlochova, P. Bezdicka, J. Bohacek, D. Dvoranowa, et al. V. N-Doped titanium dioxide nanosheets: Preparation, characterization and UV/visible-light activity. Applied Catalysis B: Environmental, Vol. 232, 2018, pp. 397–408.10.1016/j.apcatb.2018.03.053Search in Google Scholar

[18] Rudakova, A. V., A. V. Emeline, A. I. Romanychev, and D. W. Bahnemann. Photoinduced hydrophobic behavior of TiO2 thin film on Si substrate. Journal of Alloys and Compounds, Vol. 872, 2021, id. 159746.10.1016/j.jallcom.2021.159746Search in Google Scholar

[19] Augustyniak-Jabłokow, M. A., R. Strzelczyk, and R. Fedaruk. Localization of conduction electrons in hydrothermally reduced graphene oxide: electron paramagnetic resonance studies. Carbon, Vol. 168, 2020, pp. 665–672.10.1016/j.carbon.2020.07.023Search in Google Scholar

[20] Sienkiewicz, A., P. Rokicka-Konieczna, A. Wanag, E. Kusiak-Nejman, and A. W. Morawski. Artificial solar light-driven APTES/TiO2 photocatalysts for methylene blue removal from water. Molecules, Vol. 27, 2022, id. 947.10.3390/molecules27030947Search in Google Scholar PubMed PubMed Central

[21] Augustyniak-Jabłkow, M. A., R. Strzelczyk, and R. Fedaruk. Localization of conduction electrons in hydrothermally reduced graphene oxide: Electron paramagnetic resonance studies. Carbon, Vol. 168, 2020, pp. 665–672. 10.1016/j.carbon.2020.07.023.Search in Google Scholar

[22] Guskos, N., G. Zolnierkiewicz, A. Guskos, K. Aidinis, A. Wanag, E. Kusiak-Nejman, et al. Magnetic moment centers in titanium dioxide photocatalysts loaded on reduced graphene oxide flakes. Reviews on Advanced Materials Science, Vol. 60, 2021, pp. 57–63.10.1515/rams-2021-0012Search in Google Scholar
Received: 2022-04-27
Revised: 2022-07-01
Accepted: 2022-08-09
Published Online: 2022-10-12

© 2022 Agnieszka Sienkiewicz et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Review Articles
  2. State of the art, challenges, and emerging trends: Geopolymer composite reinforced by dispersed steel fibers
  3. A review on the properties of concrete reinforced with recycled steel fiber from waste tires
  4. Copper ternary oxides as photocathodes for solar-driven CO2 reduction
  5. Properties of fresh and hardened self-compacting concrete incorporating rice husk ash: A review
  6. Basic mechanical and fatigue properties of rubber materials and components for railway vehicles: A literature survey
  7. Research progress on durability of marine concrete under the combined action of Cl− erosion, carbonation, and dry–wet cycles
  8. Delivery systems in nanocosmeceuticals
  9. Study on the preparation process and sintering performance of doped nano-silver paste
  10. Analysis of the interactions between nonoxide reinforcements and Al–Si–Cu–Mg matrices
  11. Research Articles
  12. Study on the influence of structural form and parameters on vibration characteristics of typical ship structures
  13. Deterioration characteristics of recycled aggregate concrete subjected to coupling effect with salt and frost
  14. Novel approach to improve shale stability using super-amphiphobic nanoscale materials in water-based drilling fluids and its field application
  15. Research on the low-frequency multiline spectrum vibration control of offshore platforms
  16. Multiple wide band gaps in a convex-like holey phononic crystal strip
  17. Response analysis and optimization of the air spring with epistemic uncertainties
  18. Molecular dynamics of C–S–H production in graphene oxide environment
  19. Residual stress relief mechanisms of 2219 Al–Cu alloy by thermal stress relief method
  20. Characteristics and microstructures of the GFRP waste powder/GGBS-based geopolymer paste and concrete
  21. Development and performance evaluation of a novel environmentally friendly adsorbent for waste water-based drilling fluids
  22. Determination of shear stresses in the measurement area of a modified wood sample
  23. Influence of ettringite on the crack self-repairing of cement-based materials in a hydraulic environment
  24. Multiple load recognition and fatigue assessment on longitudinal stop of railway freight car
  25. Synthesis and characterization of nano-SiO2@octadecylbisimidazoline quaternary ammonium salt used as acidizing corrosion inhibitor
  26. Perforated steel for realizing extraordinary ductility under compression: Testing and finite element modeling
  27. The influence of oiled fiber, freeze-thawing cycle, and sulfate attack on strain hardening cement-based composites
  28. Perforated steel block of realizing large ductility under compression: Parametric study and stress–strain modeling
  29. Study on dynamic viscoelastic constitutive model of nonwater reacted polyurethane grouting materials based on DMA
  30. Mechanical behavior and mechanism investigation on the optimized and novel bio-inspired nonpneumatic composite tires
  31. Effect of cooling rate on the microstructure and thermal expansion properties of Al–Mn–Fe alloy
  32. Research on process optimization and rapid prediction method of thermal vibration stress relief for 2219 aluminum alloy rings
  33. Failure prevention of seafloor composite pipelines using enhanced strain-based design
  34. Deterioration of concrete under the coupling action of freeze–thaw cycles and salt solution erosion
  35. Creep rupture behavior of 2.25Cr1Mo0.25V steel and weld for hydrogenation reactors under different stress levels
  36. Statistical damage constitutive model for the two-component foaming polymer grouting material
  37. Nano-structural and nano-constraint behavior of mortar containing silica aggregates
  38. Influence of recycled clay brick aggregate on the mechanical properties of concrete
  39. Effect of LDH on the dissolution and adsorption behaviors of sulfate in Portland cement early hydration process
  40. Comparison of properties of colorless and transparent polyimide films using various diamine monomers
  41. Study in the parameter influence on underwater acoustic radiation characteristics of cylindrical shells
  42. Experimental study on basic mechanical properties of recycled steel fiber reinforced concrete
  43. Dynamic characteristic analysis of acoustic black hole in typical raft structure
  44. A semi-analytical method for dynamic analysis of a rectangular plate with general boundary conditions based on FSDT
  45. Research on modification of mechanical properties of recycled aggregate concrete by replacing sand with graphite tailings
  46. Dynamic response of Voronoi structures with gradient perpendicular to the impact direction
  47. Deposition mechanisms and characteristics of nano-modified multimodal Cr3C2–NiCr coatings sprayed by HVOF
  48. Effect of excitation type on vibration characteristics of typical ship grillage structure
  49. Study on the nanoscale mechanical properties of graphene oxide–enhanced shear resisting cement
  50. Experimental investigation on static compressive toughness of steel fiber rubber concrete
  51. Study on the stress field concentration at the tip of elliptical cracks
  52. Corrosion resistance of 6061-T6 aluminium alloy and its feasibility of near-surface reinforcements in concrete structure
  53. Effect of the synthesis method on the MnCo2O4 towards the photocatalytic production of H2
  54. Experimental study of the shear strength criterion of rock structural plane based on three-dimensional surface description
  55. Evaluation of wear and corrosion properties of FSWed aluminum alloy plates of AA2020-T4 with heat treatment under different aging periods
  56. Thermal–mechanical coupling deformation difference analysis for the flexspline of a harmonic drive
  57. Frost resistance of fiber-reinforced self-compacting recycled concrete
  58. High-temperature treated TiO2 modified with 3-aminopropyltriethoxysilane as photoactive nanomaterials
  59. Effect of nano Al2O3 particles on the mechanical and wear properties of Al/Al2O3 composites manufactured via ARB
  60. Co3O4 nanoparticles embedded in electrospun carbon nanofibers as free-standing nanocomposite electrodes as highly sensitive enzyme-free glucose biosensors
  61. Effect of freeze–thaw cycles on deformation properties of deep foundation pit supported by pile-anchor in Harbin
  62. Temperature-porosity-dependent elastic modulus model for metallic materials
  63. Effect of diffusion on interfacial properties of polyurethane-modified asphalt–aggregate using molecular dynamic simulation
  64. Experimental study on comprehensive improvement of shear strength and erosion resistance of yellow mud in Qiang Village
  65. A novel method for low-cost and rapid preparation of nanoporous phenolic aerogels and its performance regulation mechanism
  66. In situ bow reduction during sublimation growth of cubic silicon carbide
  67. Adhesion behaviour of 3D printed polyamide–carbon fibre composite filament
  68. An experimental investigation and machine learning-based prediction for seismic performance of steel tubular column filled with recycled aggregate concrete
  69. Effects of rare earth metals on microstructure, mechanical properties, and pitting corrosion of 27% Cr hyper duplex stainless steel
  70. Application research of acoustic black hole in floating raft vibration isolation system
  71. Multi-objective parametric optimization on the EDM machining of hybrid SiCp/Grp/aluminum nanocomposites using Non-dominating Sorting Genetic Algorithm (NSGA-II): Fabrication and microstructural characterizations
  72. Estimating of cutting force and surface roughness in turning of GFRP composites with different orientation angles using artificial neural network
  73. Displacement recovery and energy dissipation of crimped NiTi SMA fibers during cyclic pullout tests
https://doi.org/10.1515/rams-2022-0264
Keywords for this article
APTES-modified TiO; photoactivity; EPR measurements
Creative Commons
BY 4.0

Articles in the same Issue

  1. Review Articles
  2. State of the art, challenges, and emerging trends: Geopolymer composite reinforced by dispersed steel fibers
  3. A review on the properties of concrete reinforced with recycled steel fiber from waste tires
  4. Copper ternary oxides as photocathodes for solar-driven CO2 reduction
  5. Properties of fresh and hardened self-compacting concrete incorporating rice husk ash: A review
  6. Basic mechanical and fatigue properties of rubber materials and components for railway vehicles: A literature survey
  7. Research progress on durability of marine concrete under the combined action of Cl− erosion, carbonation, and dry–wet cycles
  8. Delivery systems in nanocosmeceuticals
  9. Study on the preparation process and sintering performance of doped nano-silver paste
  10. Analysis of the interactions between nonoxide reinforcements and Al–Si–Cu–Mg matrices
  11. Research Articles
  12. Study on the influence of structural form and parameters on vibration characteristics of typical ship structures
  13. Deterioration characteristics of recycled aggregate concrete subjected to coupling effect with salt and frost
  14. Novel approach to improve shale stability using super-amphiphobic nanoscale materials in water-based drilling fluids and its field application
  15. Research on the low-frequency multiline spectrum vibration control of offshore platforms
  16. Multiple wide band gaps in a convex-like holey phononic crystal strip
  17. Response analysis and optimization of the air spring with epistemic uncertainties
  18. Molecular dynamics of C–S–H production in graphene oxide environment
  19. Residual stress relief mechanisms of 2219 Al–Cu alloy by thermal stress relief method
  20. Characteristics and microstructures of the GFRP waste powder/GGBS-based geopolymer paste and concrete
  21. Development and performance evaluation of a novel environmentally friendly adsorbent for waste water-based drilling fluids
  22. Determination of shear stresses in the measurement area of a modified wood sample
  23. Influence of ettringite on the crack self-repairing of cement-based materials in a hydraulic environment
  24. Multiple load recognition and fatigue assessment on longitudinal stop of railway freight car
  25. Synthesis and characterization of nano-SiO2@octadecylbisimidazoline quaternary ammonium salt used as acidizing corrosion inhibitor
  26. Perforated steel for realizing extraordinary ductility under compression: Testing and finite element modeling
  27. The influence of oiled fiber, freeze-thawing cycle, and sulfate attack on strain hardening cement-based composites
  28. Perforated steel block of realizing large ductility under compression: Parametric study and stress–strain modeling
  29. Study on dynamic viscoelastic constitutive model of nonwater reacted polyurethane grouting materials based on DMA
  30. Mechanical behavior and mechanism investigation on the optimized and novel bio-inspired nonpneumatic composite tires
  31. Effect of cooling rate on the microstructure and thermal expansion properties of Al–Mn–Fe alloy
  32. Research on process optimization and rapid prediction method of thermal vibration stress relief for 2219 aluminum alloy rings
  33. Failure prevention of seafloor composite pipelines using enhanced strain-based design
  34. Deterioration of concrete under the coupling action of freeze–thaw cycles and salt solution erosion
  35. Creep rupture behavior of 2.25Cr1Mo0.25V steel and weld for hydrogenation reactors under different stress levels
  36. Statistical damage constitutive model for the two-component foaming polymer grouting material
  37. Nano-structural and nano-constraint behavior of mortar containing silica aggregates
  38. Influence of recycled clay brick aggregate on the mechanical properties of concrete
  39. Effect of LDH on the dissolution and adsorption behaviors of sulfate in Portland cement early hydration process
  40. Comparison of properties of colorless and transparent polyimide films using various diamine monomers
  41. Study in the parameter influence on underwater acoustic radiation characteristics of cylindrical shells
  42. Experimental study on basic mechanical properties of recycled steel fiber reinforced concrete
  43. Dynamic characteristic analysis of acoustic black hole in typical raft structure
  44. A semi-analytical method for dynamic analysis of a rectangular plate with general boundary conditions based on FSDT
  45. Research on modification of mechanical properties of recycled aggregate concrete by replacing sand with graphite tailings
  46. Dynamic response of Voronoi structures with gradient perpendicular to the impact direction
  47. Deposition mechanisms and characteristics of nano-modified multimodal Cr3C2–NiCr coatings sprayed by HVOF
  48. Effect of excitation type on vibration characteristics of typical ship grillage structure
  49. Study on the nanoscale mechanical properties of graphene oxide–enhanced shear resisting cement
  50. Experimental investigation on static compressive toughness of steel fiber rubber concrete
  51. Study on the stress field concentration at the tip of elliptical cracks
  52. Corrosion resistance of 6061-T6 aluminium alloy and its feasibility of near-surface reinforcements in concrete structure
  53. Effect of the synthesis method on the MnCo2O4 towards the photocatalytic production of H2
  54. Experimental study of the shear strength criterion of rock structural plane based on three-dimensional surface description
  55. Evaluation of wear and corrosion properties of FSWed aluminum alloy plates of AA2020-T4 with heat treatment under different aging periods
  56. Thermal–mechanical coupling deformation difference analysis for the flexspline of a harmonic drive
  57. Frost resistance of fiber-reinforced self-compacting recycled concrete
  58. High-temperature treated TiO2 modified with 3-aminopropyltriethoxysilane as photoactive nanomaterials
  59. Effect of nano Al2O3 particles on the mechanical and wear properties of Al/Al2O3 composites manufactured via ARB
  60. Co3O4 nanoparticles embedded in electrospun carbon nanofibers as free-standing nanocomposite electrodes as highly sensitive enzyme-free glucose biosensors
  61. Effect of freeze–thaw cycles on deformation properties of deep foundation pit supported by pile-anchor in Harbin
  62. Temperature-porosity-dependent elastic modulus model for metallic materials
  63. Effect of diffusion on interfacial properties of polyurethane-modified asphalt–aggregate using molecular dynamic simulation
  64. Experimental study on comprehensive improvement of shear strength and erosion resistance of yellow mud in Qiang Village
  65. A novel method for low-cost and rapid preparation of nanoporous phenolic aerogels and its performance regulation mechanism
  66. In situ bow reduction during sublimation growth of cubic silicon carbide
  67. Adhesion behaviour of 3D printed polyamide–carbon fibre composite filament
  68. An experimental investigation and machine learning-based prediction for seismic performance of steel tubular column filled with recycled aggregate concrete
  69. Effects of rare earth metals on microstructure, mechanical properties, and pitting corrosion of 27% Cr hyper duplex stainless steel
  70. Application research of acoustic black hole in floating raft vibration isolation system
  71. Multi-objective parametric optimization on the EDM machining of hybrid SiCp/Grp/aluminum nanocomposites using Non-dominating Sorting Genetic Algorithm (NSGA-II): Fabrication and microstructural characterizations
  72. Estimating of cutting force and surface roughness in turning of GFRP composites with different orientation angles using artificial neural network
  73. Displacement recovery and energy dissipation of crimped NiTi SMA fibers during cyclic pullout tests
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 13.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/rams-2022-0264/html?lang=en
Scroll to top button