Home Physical Sciences Synthesis of magnetic photocatalyst and sensitization properties of polypyrrole
Article Open Access

Synthesis of magnetic photocatalyst and sensitization properties of polypyrrole

  • Xiaofeng Yang EMAIL logo , Lei Zhang , Zhiping Chen , Hongxia Jing , Yuzhe Chen and Qiaoling Li
Published/Copyright: November 28, 2014
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Science and Engineering of Composite Materials
From the journal Science and Engineering of Composite Materials Volume 23 Issue 3

Abstract

In order to solve the difficulty of separation and recycling of TiO2 and its lower utilization of solar radiation, a new type of TiO2 photocatalyst, which was sensitized by polypyrrole (PPy) and carried by self-made modified Fe3O4, named PPy-TiO2/M-Fe3O4, was fabricated successfully by combining suspension dispersion and in situ polymerization. The structure of photocatalyst and Fe3O4 was characterized using X-ray diffraction, the Fourier transmission infrared spectrometer, and scanning electron microscopy. Light response property was tested by ultraviolet-visible diffuse reflectance spectra. Photocatalytic activity was evaluated with methyl orange as the degradation substance under different light radiation. Magnetic recovery property was investigated by using vibrating sample magnetometer and gravimetric analysis methods. The results showed that due to sensitization of PPy, the light response scope of PPy-TiO2/M-Fe3O4 was broadened to 451 nm and the degradation rate of methyl orange had been increased by 32.5% under the same conditions. Meanwhile, the recovery rate of PPy-TiO2/M-Fe3O4 remained above 97.9% after five cycles.

Keywords: Fe3O4; magnetic photocatalysts; polypyrrole; sensitized; TiO2

1 Introduction

Owing to relatively higher catalytic activity, higher chemical stability, non-toxicity, and a deeper mineralization ability for organic and inorganic pollutants, TiO2 has been widely used as a photocatalyst and it is recognized as one of the most promising materials in photocatalyst fields [1, 2]. Due to the difficulty of separation and recycling in suspension system and the broaden band gap (3.2 eV) of TiO2, photocatalytic oxidation technologies of TiO2 are still immature at present. Most of them are at the stage of simulation wastewater treatment in the laboratory and cannot be used in practical applications. At the same time, a narrow spectral response range of TiO2 limits utilization of solar energy (ultraviolet light is about 5% in solar radiation). Therefore, scientists have carried out numerous fruitful works to solve the problems. On the one hand, they combined nano-TiO2 with magnetic particles [3, 4] and fabricated magnetic photocatalyst. The most widely used fabrication methods include sol-gel [5, 6], liquid deposition [7], and high-speed ball milling [8]. On the other hand, they expanded the spectral response range of TiO2 by doping or modification. The commonly used methods have semiconductor coupling [9], co-doping [10–12], and surface sensitization methods [13, 14]. Among above methods, the surface sensitization method has an excellent effect in expanding the spectral response range of TiO2 to the visible region, and further improving utilization of solar energy. It has become one of the most effective ways.

Polypyrrole (PPy) has good environmental stability and strong absorption on the visible region as a heterocyclic ring conjugate conductive macromolecule. PPy is also a strong electron donor and excellent hole transporting material. Kawakita and Balraju et al. [15, 16] demonstrated that sensitization of a conductive macromolecular, such as PPy and polyaniline, may expand the spectral response range of TiO2 to the visible region, prompting separation of photoelectron and hole. The sensitization of conductive macromolecular can further improve the photo catalytic property of TiO2. Based on the background, we put forward to synthesis a new type of TiO2 photocatalyst sensitized with polypyrrole and carried by Fe3O4. The photocatalyst was fabricated by combining suspension dispersion and in situ polymerization. The schematic of preparation for photocatalyst is shown in Figure 1. The photocatalytic activity and magnetic recovery properties were researched.

Figure 1 The schematic preparation of a photocatalyst.
Figure 1

The schematic preparation of a photocatalyst.

2 Materials and methods

2.1 Fabrication of magnetic TiO2 photocatalysts sensitized by PPy

2.1.1 Synthesis of magnetic substrate of Fe3O4 [17] and its surface modification

Magnetic substrate was prepared using the co-precipitation method with ferrous sulfate (FeSO4·7H2O) and ferric sulfate (Fe2(SO4)3) as starting materials along with sodium hydrate (NaOH) as the precipitator. All the reagents were analysis pure and used as received without further purification. A typical synthesis process for Fe3O4 was as following: stoichiometry amount of FeSO4·7H2O, Fe2(SO4)3 were dissolved in deionized water with mole rate nFe2+:nFe3+=1:1 continuously agitated at 55°C. The pH values of above solution were adjusted to 7.5 with 2 mol/l sodium hydroxide solution, then heated to 60°C and reacted at constant temperature for 6 h. The precipitate was settled with a magnet, afterward washed with deionized water and absolute ethyl alcohol. The residual was dried at room temperature to obtain Fe3O4.

The surface of Fe3O4 was modified with γ-Chloropropyltrimethoxysilane (A-143) as a modifier. The experimental procedure was as following: first, a certain amount of A-143 was dissolved into an alcohol-water mixture with volume rate 1:3 to obtain 1 vol% A-143 solution. Next, the pH value of the solution was adjusted to the range of 3–4 with glacial acetic acid. After that, Fe3O4 were added into the above solutions, reacted for 1.3 h, and continuously agitated at 80°C. The reaction mixture were filtered. The residual was washed with alcohol to remove unreacted materials, dryed at 100°C for 2 h, and named M-Fe3O4.

2.1.2 Preparation [18] of photocatalyst carried by Fe3O4

Magnetic photocatalyst TiO2 was obtained according to following procedures. First, a certain amount of M-Fe3O4 was dispersed into 40 vol% tetrabutyl titanate solution of ethanoal with solid-to-liquid ratio 1 g:13 ml by employing ultrasonic dispersion instrument. Next, a solution, obtained by mixed ethyl alcohol, glacial acetic acid, and deionied water with volume rate 1:1:1, was slowly droped into the above suspension. Hydrolysate of tereabutyl titanate was adsorbed on the surface of M-Fe3O4, and crosslinked with surperficial hydroxide radical of M-Fe3O4. Subsequenly, the suspend was filtered, and washed with ethnol and deionized water five times. The residual was dried at 80°C for 24 h and roasted at 550°C for 24 h. Magnetic photocatalyst TiO2 was obtained, named hereafter TiO2/M-Fe3O4.

2.1.3 Fabrication of photocatalyst sensitized by PPy and carried by Fe3O4

Photocatalyst sensitized with PPy and carried by Fe3O4 was obtained by in situ polymerization reaction of pyrrole monomer on the surface of TiO2/M-Fe3O4. First, TiO2/M-Fe3O4 along with pyorrle at mole ratio 1:0.07 was dispersed into 1.0 mol/l hydrochloric acid solution at 0–3°C with ustrasonic dispersion. A certain amount of 0.1 mol/l FeCl3 with mole rate nFe3+:npyorrle=1:1 was slowly dropped into the above mixtures and stirred vigorously at 0–3°C for 12 h. Afterwards, the suspend was filtered, the residual was washed repeatedly with absolute ethyl alcohol and water and it was dried at 50°C. A brown power was obtained, named PPy-TiO2/M-Fe3O4.

2.2 Characterization

The composition of phase and crystal structure of the sample was determined with a D/max-rA X-ray diffractometer (Rigaku Co., Koyto, Japan) using Cu kα(λ=1.5406 Å) radiation at room temperature in the 2 theta ranges from 20° to 80°. Organic function chansformation of samples was tested by employing an FTIR-8400 Fourier transform infrared spectrometer (FT-IR) (Shimadzu Co., Tokyo, Japan). Absorbance of solution along with ultraviolet visible diffused reflection of samples were conducted by using an UV-2600 ultraviolet and visible spectrophotometer (Shimadzu Co., Tokyo, Japan). The surface morphology of samples were observed with an SU-70 scanning electron microscope (SEM) (Hitachi Co., Koyto, Japan). The magnetic properties of the samples were tested using a vibrating sample magnetometer (VSM) (Nanjing Nanda Instrument Plant, Nanjing, China) at room temperature under a maximum field of 15 T.

2.3 Test of photocatalytic properties

The photocatalytic properties of PPy-TiO2/M-Fe3O4 were evaluated by employing methyl orange as target degradation product. Photocatalyst was added into 6 mg/l methyl orange solution with solid-to-liquid 1 g:1 l in a quartz beaker and dispersed with ultrasonic instrument for 20 min to establish balance of adsorption-desorption. Afterwards, the mixture was exposed under ultraviolet radiation at a fixed distance with stirring. The absorbance of upper transparent solution was measured at 30 min intervals to evaluate photocatalytic activity of PPy-TiO2/M-Fe3O4. The degradation rate (η) of methyl orange was calculated with Equation (1).

(1)η=[(A0-A)/A0]×100%=[(C0−C)/C0]×100% (1)

where A0, A and C0, C are the absorbance and concentration of methyl orange solution at the beginning and after degrading, respectively.

In order to research the influence of different radiation on photocatalyst properties, solar radiation was employed to degrade methyl orange solution with similar methods. Furthermore, TiO2 also was used to replace magnetic photocatalyst for comparing the influence of Fe3O4.

2.4 Recycle properties of photocatalyst

The recycle property of PPy-TiO2/M-Fe3O4 was investigated by using gravimetric analysis methods. After photocatalytic reaction was completed, PPy-TiO2/M-Fe3O4 was recycled with magnetic force, washed and dried. The recycling rate (R) of PPy-TiO2/M-Fe3O4 was calculated with Equation (2).

(2)R=mn/m0 (2)

where m0 is initial mass of photocatalyst, and mn is the mass of photocatalyst after n time cycles.

3 Results and discussion

3.1 Structute characters of sample and morphology observation

3.1.1 X-ray diffraction (XRD)

Figure 2 shows the XRD patterns of Fe3O4, M-Fe3O4 modified with A-143 and TiO2/M-Fe3O4 coated with TiO2. The dominant diffraction peaks of Fe3O4 were in accordance with spinel structure of Fe3O4 (JCPDS no. 72-2303). and the peaks at 2 theta 30.00°, 35.58°, 432.08°, 53.52°, 56.96°, and 62.74° corresponded to the lattice plane (220), (311), (400), (422), (511), and (440), respectively. Compared to Fe3O4, the diffraction peaks position of M-Fe3O4 was without any change, while relative intensity was weakened. As shown, the crystal form of M-Fe3O4 modified with A-143 was the same with Fe3O4, but relative crystallinity of M-Fe3O4 was slightly decreased compared to that of Fe3O4. The above phenomenon were mainly caused by the dilution and dispersion effect of the silane coupling agent, which was a non-crystalline material.

Figure 2 X-ray diffraction patterns of Fe3O4, M-Fe3O4, and TiO2/Fe3O4.
Figure 2

X-ray diffraction patterns of Fe3O4, M-Fe3O4, and TiO2/Fe3O4.

Compared with Fe3O4 in Figure 2, we found several new diffraction peaks in the XRD pattern of TiO2/M-Fe3O4 at 2 theta 25.36°, 37.74°, and 48.00°. These peaks corresponded to the diffraction of lattice plane (101), (004), and (200) of TiO2 with anatase structure (JCPDS no.21-1274), respectively. The appearance of above diffraction peaks indicated that there were two kinds of structure intergrowth in TiO2/M-Fe3O4. One was Fe3O4 and another was TiO2. In addition, relative intensity of diffraction for Fe3O4 was obviously weaker than that for virgin Fe3O4. As mentioned above, dilution and dispersion effects of non-crystalline materials were the main reason.

3.1.2 FT-IR

Figure 3 gives the FT-IR spectra of A-143, Fe3O4, and M-Fe3O4. The characteristic absorption band of 1080 cm-1 was attributed to as-symmetry stretching vibration of Si-O bond in the spectrum of A-143. In addition, the characteristic absorption band of 587 cm-1 was attributed to the stretching vibration M-O band in Fe3O4.

Figure 3 Fourier transform infrared spectrometer spectra of A-143, Fe3O4, and M-Fe3O4.
Figure 3

Fourier transform infrared spectrometer spectra of A-143, Fe3O4, and M-Fe3O4.

Compared with A-143 and Fe3O4, there are both characteristic absorption bands for Si-O and M-O in the spectrum of M-Fe3O4, which appeared at 1080 cm-1 and 592 cm-1, respectively. At the same time, the absorption band of CH2 for in-plane flexural vibration, as well as C-H for as-symmetry and symmetry stretching vibration, were also found in the spectrum of M-Fe3O4 at 1456 cm-1, 2920 cm-1, and 2846 cm-1, respectively. The appearances of these absorption bands revealed that A-143 has combined with Fe3O4. In addition, there was a slightly blue-shift for the absorption of M-O (5 cm-1) bond in the spectrum of M-Fe3O4. The fact indicated that electron cloud density and force constant of M-O bond was increased with modification of A-143. This blue-shift also verified the combining of A-143 with Fe3O4.

3.1.3 SEM

The morphology of the Fe3O4, TiO2/M-Fe3O4, and PPy-TiO2/M- Fe3O4 is shown in Figure 4. All particle exhibits sphere shapes except for partly out-of-shape in TiO2/M-Fe3O4. It should be mentioned that the particle morphology of PPy-TiO2/M-Fe3O4 is rougher and brighter than that of Fe3O4 and TiO2/M-Fe3O4. The changes indicated that PPy have coated the surface of TiO2/M- Fe3O4.

Figure 4 Scanning electron microscope of Fe3O4, TiO2/MFe3O4, and PPy-TiO2/MFe3O4.
Figure 4

Scanning electron microscope of Fe3O4, TiO2/MFe3O4, and PPy-TiO2/MFe3O4.

3.2 Activity of photocatalyst

With methyl orange as the target degradation product, photocatalytic properties of TiO2, TiO2/M-Fe3O4, and PPy-TiO2/M-Fe3O4 were researched under ultraviolet radiation. The change of degradation rate relative to time is shown in Figure 5. All three different catalysts showed catalytic activity on the degradation of methyl orange. The degradation rate of methyl orange increased gradually with degradation time increases. When degradation time was 120 min, degradation rate of methyl orange with PPy-TiO2/M-Fe3O4 as the catalyst reached 93.4%, which was nearly completely achieved. Comparing the data in Figure 4, it can be found that the degradation rate (e.g., 90.6% at 90 min) with PPy-TiO2/M-Fe3O4 as catalyst was higher than that with virgin TiO2 (83.4%) or TiO2/M-Fe3O4 (72.6%) for the same degradation time. As indicated, the sensitization of PPy enhanced the catalytic activity of TiO2.

Figure 5 Methyl orange degradation rate-time curves under ultraviolet light.
Figure 5

Methyl orange degradation rate-time curves under ultraviolet light.

In order to further research the practical application properties of all types of catalyst, experiments were carried out under solar radiation. The changes of degradation rate of methyl orange are shown in Figure 6. It can be seen from Figure 6 that the catalytic activity of all kinds of catalyst under solar radiation was in accordance with that under ultraviolet radiation. PPy-TiO2/M-Fe3O4 ranked first, followed by TiO2 and TiO2/M-Fe3O4 in that order. In addition, it was hard to ignore that the degradation rate for the same catalyst under solar radiation was lower than that under ultraviolet radiation at similar condition. For example, the degradation rate (59.3%) for PPy-TiO2/M-Fe3O4 under solar radiation was 31.3% lower than that under ultraviolet radiation at 90 min.

Figure 6 Methyl orange degradation rate-time curves under sunlight.
Figure 6

Methyl orange degradation rate-time curves under sunlight.

By further comparing the influence of radiation source on the degradation rate for different samples, it can be found the change of degradation rate under solar radiation was larger than that under ultraviolet radiation. When degradation time was fixed at 90 min, for example, the value of degradation rate for PPy-TiO2/M-Fe3O4 was about 32.5% higher than that for virgin TiO2 (26.8%), and about 40.0%, for TiO2/M-Fe3O4 (19.3%) under solar radiation. While under ultraviolet radiation, the value difference was only 7.2% and 18.0%, respectively. The above facts indicated that the sensitization of PPy for TiO2 was more obvious in the visible region than in the ultraviolet region.

3.3 Activity discussion of photocatalyst and sensitized mechanism analysis of PPy

It is generally known that catalytic activity of TiO2 have a relationship with its band structure. When TiO2 absorb ultraviolet light, which energy is equal to or larger than its band gap, electron e- on the valance band will be excited and jump to the conduction band. Meanwhile, holes will be produced on the valance band. In fact, just these separated electrons and holes give TiO2 a photo catalytic effect, as separated electron on the surface of TiO2 can react with electron acceptor like water or oxygen. The acceptor of electron can reduce in accordance with Equations (3) and (4) [19–21] and generate new living radicals such as ·O2- and ·HO2. At the same time, separated holes can react with electron donors absorbed on the surface of TiO2 according to Equation (5), produce new higher activity radical like ·OH. This intermediate like peroxide, radical can react further with organic matter in water. Just through these redox reactions, organic matter in water realizes degradation.

(3)e-+O2→·O2- (3)
(4)·O2-+H2O→HO2+OH- (4)
(5)h++OH-→·OH (5)

When ultraviolet radiation was used as radiation source, pairs of electrons and holes separated efficiently for all of the above catalysts. Sensitization of PPy had no significant influence on the separation of electrons and holes pairs. Therefore, the catalytic ability had no distinct difference for the catalyst before and after sensitization, resulting in a slight difference of degradation rate for PPy-TiO2/M-Fe3O4 and TiO2/M-Fe3O4 under ultraviolet radiation at the same condition. At the same time, due to ultraviolet light only accounting for 5% of solar radiation, separation of pairs of electrons-holes under solar radiation was more difficult than that under ultraviolet radiation. This results in the degradation rate of methyl orange under solar radiation being obviously lower than that under ultraviolet radiation at the same conditions.

When sensitizing the surface of TiO2 with appropriate amount PPy, the spectral response range of TiO2 will expand to the visible region [22, 23]. The sensitization principle of PPy on TiO2 is shown in Figure 7 and sensitization of PPy was verified by UV-vis diffuse reflection spectrum of TiO2 and PPy-TiO2/M-Fe3O4 also shown in Figure 8. It can be found from Figure 8 that the absorption edge of TiO2 was 39 9 nm and the band gap was about 3.11 eV, which was closer the intrinsic band gap of TiO2. While absorption edge of PPy-TiO2/M-Fe3O4 was 451 nm, the band gap was about 2.75 eV. The results showed that absorption edge of PPy-TiO2/M-Fe3O4 was more red shift than TiO2. After modified with PPy, the absorption intensity of PPy-TiO2/M-Fe3O4 to ultraviolet and visible light was enhanced. The decrease of band gap and increase of absorption intensity indicated that spectral response range of PPy-TiO2/M-Fe3O4 was broadened. Compared with unsensitized TiO2, therefore, the methyl orange degradation rate with sensitized PPy-TiO2/M-Fe3O4 as catalyst was improved obviously under solar radiation. That is in accordance with the experiments. That is to say, the sensitization effect of PPy on TiO2 was more obvious under solar radiation than that under ultraviolet radiation.

Figure 7 The sensitization principle of polypyrrole on TiO2.
Figure 7

The sensitization principle of polypyrrole on TiO2.

Figure 8 Ultraviolet-visible diffuse reflectance spectra of TiO2 before and after being sensitized by PPy.
Figure 8

Ultraviolet-visible diffuse reflectance spectra of TiO2 before and after being sensitized by PPy.

3.4 Analysis of magnetism and magic recycle property of photocatalyst

The recycling property of magnetic photocatalyst was one of the important factors for practical application. Figure 9 shows the magnetic hysteresis loop of Fe3O4, M-Fe3O4, TiO2/M-Fe3O4, and PPy-TiO2/M-Fe3O4. It can be seen that the values of coercivity and remanent magnetization for all samples are nearly zero, which shows that all samples had superparamagnetism property. In addition, this property ensures the particles as TiO2/M-Fe3O4 and PPy-TiO2/M-Fe3O4 can finely disperse in solution. Furthermore, due to loading with a nonmagnetic component, such as TiO2 and/or PPy, the saturation magnetization values of samples TiO2/M-Fe3O4 and PPy-TiO2/M-Fe3O4 are lower than that of Fe3O4 or M-Fe3O4. However, the saturation magnetization values of PPy-TiO2/M-Fe3O4 reach 44.2 emu·g-1, and ensure that the particles can recycle well under the effect of magnetic field.

Figure 9 Magnetic hysteresis loop of Fe3O4, M-Fe3O4, TiO2/MFe3O4, and PPy-TiO2/MFe3O4.
Figure 9

Magnetic hysteresis loop of Fe3O4, M-Fe3O4, TiO2/MFe3O4, and PPy-TiO2/MFe3O4.

The relationship between recycling rate and cycle time of TiO2 and PPy-TiO2/M-Fe3O4 is shown in Figure 10. From Figure 10, it can be found that the recycling rate for TiO2 was only 49.3% after one cycle, and 21.6% after three cycles. While for PPy-TiO2/M-Fe3O4, the recycling rate remained above 97.9% after five cycles. The facts made clear the good recycling property of PPy-TiO2/M-Fe3O4.

Figure 10 Magnetic recovery curves of TiO2 and PPy-TiO2/MFe3O4 samples.
Figure 10

Magnetic recovery curves of TiO2 and PPy-TiO2/MFe3O4 samples.

4 Conclusion

PPy-TiO2/M-Fe3O4, sensitized with PPy and carried with Fe3O4, was fabricated successfully by combining suspension-ultrasonic and surface in situ polymerization methods. The new catalyst had both visible spectral response and magnetic recovery properties. The sensitization of PPy extended the spectral response range of TiO2 to 451 nm and raised the photo catalytic efficiency under solar radiation. The degradation rate of methyl orange with PPy-TiO2/M-Fe3O4 as catalyst was about 32.5% higher than that with virgin TiO2 as catalyst. Meanwhile, the catalyst had good recovery properties with a 97.9% recycling rate after five cycles.

Corresponding author: Xiaofeng Yang, Department of Chemistry, School of Science, North University of China, Taiyuan 030051, P.R. China, e-mail:

Acknowledgments

The study has been supported by the Natural Science Foundation of Shanxi (Grant No. 2011021021-5, 2010021022-3), and by the Open Projects of Key Laboratory of Photochemical Conversion and Optoelectronic Materials, TIPC, CAS.

References

[1] Hagfeldt A, Gratzel M. Chem. Rev. 1995, 95, 49–68.10.1021/cr00033a003Search in Google Scholar

[2] Kyung H, Lee J, Choi WY. Environ. Sci. Technol. 2005, 39, 2376–2382.10.1021/es0492788Search in Google Scholar PubMed

[3] Wang Y, Fan X, Wang S, Zhang G, Zhang F. Mater. Res. Bull. 2013, 48, 785–789.10.1016/j.materresbull.2012.11.058Search in Google Scholar

[4] Yuan Q, Li N, Geng W, Chi Y, Li X. Mater. Res. Bull. 2012, 47, 2396–2402.10.1016/j.materresbull.2012.05.031Search in Google Scholar

[5] Fu YP, Chang WK, Wang HC, Liu CW, Lin CH. J. Mater. Res. 2010, 25, 134–140.10.1557/JMR.2010.0015Search in Google Scholar

[6] Li XY, Wang JN, Zhang LL, Li CJ. J. Mater. Sci. 2012, 47, 465–472.10.1007/s10853-011-5821-0Search in Google Scholar

[7] Harra J, Nikkanen JP, Aromaa M, Suhonen H, Honkanen M, Salminen T, Heinonen S, Levanen E, Makela JM. Powder Technol. 2013, 243, 46–52.10.1016/j.powtec.2013.03.027Search in Google Scholar

[8] Sun XY, Wang LJ, Wang J, Li JS, Li X, Wang JD. Guangpuxue Yu Guangpu Fenxi 2007, 27, 777–780.Search in Google Scholar

[9] Zhang YG, Ma LL, Li JL, Yu Y. Enviro. Sci. Technol. 2007, 41, 6264–6269.10.1021/es070345iSearch in Google Scholar PubMed

[10] Kubacka A, Bachiller-Baeza B, Colon G, Fernandez-Garcia M. J. Phys. Chem. C 2009, 113, 8553–8555.10.1021/jp902618gSearch in Google Scholar

[11] Yang XF, Chen J, Gong L, Wu MM, Yu JC. J. Am. Chem. Soc. 2009, 131, 12048–12049.10.1021/ja904337xSearch in Google Scholar PubMed

[12] You M, Kim TG, Sung YM. Cryst. Growth Des. 2010, 10, 983–987.10.1021/cg9012944Search in Google Scholar

[13] Zhao W, Sun YL, Castellano FN. J. Am. Chem. Soc. 2008, 130, 12566–12567.10.1021/ja803522vSearch in Google Scholar PubMed

[14] Li H, Zhu Y, Cao H, Yang X, Li C. Mater. Res. Bull. 2013, 48, 232–237.10.1016/j.materresbull.2012.10.052Search in Google Scholar

[15] Kawakita J. J. Electrochem. Soc. 2010, 157, II1127–II1131.10.1149/1.3502602Search in Google Scholar

[16] Balraju P, Suresh P, Kumar M, Roy MS, Sharma GD. J. Photochem. Photobiol. A 2009, 206, 53–63.10.1016/j.jphotochem.2009.05.014Search in Google Scholar

[17] Chen JY, Qian YX, Wei XZ. J. Mater. Sci. 2010, 45, 6018–6024.10.1007/s10853-010-4685-zSearch in Google Scholar

[18] Li CJ, Wang JN, Li XY, Zhang LL. J. Mater. Sci. 2011, 46, 2058–2063.10.1007/s10853-010-5038-7Search in Google Scholar

[19] Zhang H, Zong RL, Zhu YF. J. Phys. Chem. C 2009, 113, 4605–4611.10.1021/jp810748uSearch in Google Scholar

[20] Zhang H, Zhu YF. J. Phys. Chem. C 2010, 114, 5822–5826.10.1021/jp910930tSearch in Google Scholar

[21] Dutta AK, Maji SK, Adhikary B. Mater. Res. Bull. 2014, 49, 28–34.10.1016/j.materresbull.2013.08.024Search in Google Scholar

[22] Coutinho CA, Gupta VK. J. Colloid Interface Sci. 2009, 333, 457–464.10.1016/j.jcis.2009.02.016Search in Google Scholar PubMed

[23] Wang J, Ni XY. Solid State Commun. 2008, 146, 239–244.10.1016/j.ssc.2008.02.022Search in Google Scholar

Received: 2014-2-5
Accepted: 2014-7-22
Published Online: 2014-11-28
Published in Print: 2016-5-1

©2016 by De Gruyter

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Articles in the same Issue

  1. Frontmatter
  2. Original articles
  3. In vitro degradation and bioactivity of poly(propylene fumarate)/bioactive glass sintered microsphere scaffolds for bone tissue engineering
  4. Properties enhancement in multiwalled carbon nanotube-magnetite hybrid-filled polypropylene natural rubber nanocomposites through functionalization and processing methods
  5. Synthesis of magnetic photocatalyst and sensitization properties of polypyrrole
  6. Effect of silane coupling agent on the mechanical properties of nitrile butadiene rubber (NBR)/organophilic montmorillonite (OMMT) nanocomposites
  7. Monitoring of jute/hemp fiber hybrid laminates by nondestructive testing techniques
  8. Size effects on the in-plane mechanical behavior of hexagonal honeycombs
  9. Investigation on corrosion performance of multilayer Ni-P/TiO2 composite coating on steel
  10. Investigation of pozzolanic activity of volcanic rocks from the northeast of the Black Sea
  11. The effect of delayed ettringite formation on fine grained aerated concrete mechanical properties
  12. Effect of early-age freeze-thaw exposure on the mechanical performance of self-compacting repair mortars
  13. Modeling cement hydration by connecting a nucleation and growth mechanism with a diffusion mechanism. Part I: C3S hydration in dilute suspensions
https://doi.org/10.1515/secm-2014-0035
Keywords for this article
Fe3O4; magnetic photocatalysts; polypyrrole; sensitized; TiO2
Creative Commons
BY-NC-ND 3.0

Articles in the same Issue

  1. Frontmatter
  2. Original articles
  3. In vitro degradation and bioactivity of poly(propylene fumarate)/bioactive glass sintered microsphere scaffolds for bone tissue engineering
  4. Properties enhancement in multiwalled carbon nanotube-magnetite hybrid-filled polypropylene natural rubber nanocomposites through functionalization and processing methods
  5. Synthesis of magnetic photocatalyst and sensitization properties of polypyrrole
  6. Effect of silane coupling agent on the mechanical properties of nitrile butadiene rubber (NBR)/organophilic montmorillonite (OMMT) nanocomposites
  7. Monitoring of jute/hemp fiber hybrid laminates by nondestructive testing techniques
  8. Size effects on the in-plane mechanical behavior of hexagonal honeycombs
  9. Investigation on corrosion performance of multilayer Ni-P/TiO2 composite coating on steel
  10. Investigation of pozzolanic activity of volcanic rocks from the northeast of the Black Sea
  11. The effect of delayed ettringite formation on fine grained aerated concrete mechanical properties
  12. Effect of early-age freeze-thaw exposure on the mechanical performance of self-compacting repair mortars
  13. Modeling cement hydration by connecting a nucleation and growth mechanism with a diffusion mechanism. Part I: C3S hydration in dilute suspensions
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.
© 2026 De Gruyter Brill
Downloaded on 1.3.2026 from https://www.degruyterbrill.com/document/doi/10.1515/secm-2014-0035/html
Scroll to top button