Journal Home > Volume 4 , Issue 7

Nitrogen-doped HTiNbO5 nanosheets have been successfully synthesized by first exfoliating layered HTiNbO5 in tetrabutylammonium hydroxide (TBAOH) to obtain HTiNbO5 nanosheets and then heating the nanosheets with urea. The resulting samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and N2 adsorption–desorption measurements. It was found that N-doping resulted in a much higher thermostability of the layered structure, intrinsic bandgap narrowing and a visible light response. The doped nitrogen atoms were mainly located in the interstitial sites of TiNbO5 lamellae and chemically bound to hydrogen ions. Compared with N-doped HTiNbO5, N-doped HTiNbO5 nanosheets had a much larger specific surface area and richer mesoporosity due to the rather loose and irregular arrangement of titanoniobate nanosheets. Both N-doped layered HTiNbO5 and HTiNbO5 nanosheets showed a very high visible-light photocatalytic activity for the degradation of rhodamine B (RhB) aqueous solution. Moreover, due to the considerably larger surface area, richer mesoporosity and stronger acidity, N-doped HTiNbO5 nanosheets had an even higher activity than N-doped HTiNbO5, although the latter had a stronger absorption in the visible region. The dye molecules were mainly degraded to aliphatic organic compounds and partially mineralized to CO2 and/or CO, rather than being simply decolorized. The effect of photosensitization was insignificant and RhB was degraded mainly via the typical photocatalytic reaction routes. Two different reaction routes for the photodegradation of RhB under visible light irradiation over N-doped HTiNbO5 nanosheets have been proposed. The present method can be extended to a large number of layered metal oxides that have the characteristics of intercalation and exfoliation, thus providing new opportunities for the fabrication of highly effective and potentially practical visible-light photocatalysts.


menu
Abstract
Full text
Outline
About this article

Thermostable Nitrogen-Doped HTiNbO5 Nanosheets with a High Visible-Light Photocatalytic Activity

Show Author's information Zheng ZhaiYucheng HuangLin XuXiaoyan YangChenhui HuLihong ZhangYining FanWenhua Hou( )
Key Laboratory of Mesoscopic Chemistry of MOESchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing210093China

Abstract

Nitrogen-doped HTiNbO5 nanosheets have been successfully synthesized by first exfoliating layered HTiNbO5 in tetrabutylammonium hydroxide (TBAOH) to obtain HTiNbO5 nanosheets and then heating the nanosheets with urea. The resulting samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and N2 adsorption–desorption measurements. It was found that N-doping resulted in a much higher thermostability of the layered structure, intrinsic bandgap narrowing and a visible light response. The doped nitrogen atoms were mainly located in the interstitial sites of TiNbO5 lamellae and chemically bound to hydrogen ions. Compared with N-doped HTiNbO5, N-doped HTiNbO5 nanosheets had a much larger specific surface area and richer mesoporosity due to the rather loose and irregular arrangement of titanoniobate nanosheets. Both N-doped layered HTiNbO5 and HTiNbO5 nanosheets showed a very high visible-light photocatalytic activity for the degradation of rhodamine B (RhB) aqueous solution. Moreover, due to the considerably larger surface area, richer mesoporosity and stronger acidity, N-doped HTiNbO5 nanosheets had an even higher activity than N-doped HTiNbO5, although the latter had a stronger absorption in the visible region. The dye molecules were mainly degraded to aliphatic organic compounds and partially mineralized to CO2 and/or CO, rather than being simply decolorized. The effect of photosensitization was insignificant and RhB was degraded mainly via the typical photocatalytic reaction routes. Two different reaction routes for the photodegradation of RhB under visible light irradiation over N-doped HTiNbO5 nanosheets have been proposed. The present method can be extended to a large number of layered metal oxides that have the characteristics of intercalation and exfoliation, thus providing new opportunities for the fabrication of highly effective and potentially practical visible-light photocatalysts.

Keywords: N-doping, nanosheets, visible light, Layered titanoniobate, photodegradation

References(54)

1

Zhang, J.; Xu, Q.; Feng, Z.; Li, M.; Li, C. Importance of the relationship between surface phases and photocatalytic activity of TiO2. Angew. Chem. Int. Ed. 2008, 47, 1766–1769.

2

Hoffmann, M. R.; Martin, S. T.; Choi, W. Y.; Bahnemann, D. W. Environmental applications of semiconductor photocatalysis. Chem. Rev. 1995, 95, 69–96.

3

Choi, W.; Yeo, J.; Ryu, J.; Tachikawa, T.; Majima, T. Photocatalytic oxidation mechanism of As(Ⅲ) on TiO2: Unique role of As(Ⅲ) as a charge recombinant species. Environ. Sci. Technol. 2010, 44, 9099–9104.

4

Kim, G.; Choi, W. Charge-transfer surface complex of EDTA–TiO2 and its effect on photocatalysis under visible light. Appl. Catal. B 2010, 100, 77–83.

5

Chen, K. T.; Lu, C. S.; Chang, T. H.; Lai, Y. Y.; Wu, C. W.; Chen, C. C. Comparison of photodegradative efficiencies and mechanisms of victoria blue R assisted by Nafion-coated and fluorinated TiO2 photocatalysts. J. Hazard. Mater. 2010, 174, 598–609.

6

Lv, K.; Yu, J.; Deng, K.; Sun, J.; Zhao, Y.; Du, D.; Li, M. Synergistic effects of hollow structure and surface fluorination on the photocatalytic activity of titania. J. Hazard. Mater. 2010, 173, 539–543.

7

Takeuchi, M.; Deguchi, J.; Hidaka, M.; Sakai, S.; Woo, K.; Choi, P. P.; Park, J. K.; Anpo, M. Enhancement of the photocatalytic reactivity of TiO2 nano-particles by a simple mechanical blending with hydrophobic mordenite (MOR) zeolite. Appl. Catal. B 2009, 89, 406–410.

8

Ravelli, D.; Dondi, D.; Fagnoni, M.; Albini, A. An assessment of the environmental compatibility for the case of the functionalization of heterocyclics. Appl. Catal. B 2010, 99, 442–447.

9

Wu, Y. M.; Xing, M. Y.; Zhang, J. L.; Chen, F. Effective visible light-active boron and carbon modified TiO2 photo-catalyst for degradation of organic pollutant. Appl. Catal. B 2010, 97, 182–189.

10

Chen, X.; Mao, S. S. Titanium dioxide nanomaterials: Synthesis, properties, modifications, and applications. Chem. Rev. 2007, 107, 2891–2959.

11

Ollis, D.; Pichat, P.; Serpone, N. TiO2 photocatalysis—25 years. Preface. Appl. Catal. B 2010, 99, 377–377.

12

Choi, W. Y.; Termin, A.; Hoffmann, M. R. The role of metal-ion dopants in quantum-sized TiO2—Correlation between photoreactivity and charge-carrier recombination dynamics. J. Phys. Chem. 1994, 98, 13669–13679.

13

Anpo, M.; Takeuchi, M. The design and development of highly reactive titanium oxide photocatalysts operating under visible light irradiation. J. Catal. 2003, 216, 505–516.

14

Fujishima, A.; Zhang, X. T.; Tryk, D. A. TiO2 photocatalysis and related surface phenomena. Surf. Sci. Rep. 2008, 63, 515–582.

15

Hata, H.; Kobayashi, Y.; Bojan, V.; Youngblood, W. J.; Mallouk, T. E. Direct deposition of trivalent rhodium hydroxide nanoparticles onto a semiconducting layered calcium niobate for photocatalytic hydrogen evolution. Nano Lett. 2008, 8, 794–799.

16

Yan, H. J.; Yang, J. H.; Ma, G. J.; Wu, G. P.; Zong, X.; Lei, Z. B.; Shi, J. Y.; Li, C. Visible-light-driven hydrogen production with extremely high quantum efficiency on Pt-PdS/CdS photocatalyst. J. Catal. 2009, 266, 165–168.

17

Zhang, L. W.; Xu, T. G.; Zhao, X.; Zhu, Y. F. Controllable synthesis of Bi2MoO6 and effect of morphology and variation in local structure on photocatalytic activities. Appl. Catal. B 2010, 98, 138–146.

18

Yang, G.; Hou, W. H.; Feng, X. M.; Xu, L.; Liu, Y. G.; Wang, G.; Ding, W. P. Nanocomposites of polyaniline and a layered inorganic acid host: Polymerization of aniline in the layers, conformation, and electrochemical studies. Adv. Funct. Mater. 2007, 17, 401–412.

19

Yang, G.; Hou, W. H.; Feng, X. M.; Jiang, X. F.; Guo, J. Density functional theoretical studies on polyaniline/HNb3O8 layered nanocomposites. Adv. Funct. Mater. 2007, 17, 3521–3529.

20

Takagaki, A.; Tagusagawa, C.; Hayashi, S.; Hara, M.; Domen, K. Nanosheets as highly active solid acid catalysts for green chemical syntheses. Energy Environ. Sci. 2010, 3, 82–93.

21

Dias, A. S.; Lima, S.; Carriazo, D.; Rives, V.; Pillinger, M.; Valente, A. A. Exfoliated titanate, niobate and titanoniobate nanosheets as solid acid catalysts for the liquid-phase dehydration of D-xylose into furfural. J. Catal. 2006, 244, 230–237.

22

Colin, J. F.; Pralong, V.; Hervieu, M.; Caignaert, V.; Raveau, B. New titanoniobates (Li, H)2TiNbO5 and (Li, H)3TiNbO5: Synthesis, structure and properties. J. Mater. Chem. 2008, 18, 3121–3128.

23

Jang, J. S.; Kim, H. G.; Reddy, V. R.; Bae, S. W.; Ji, S. M.; Lee, J. S. Photocatalytic water splitting over iron oxide nanoparticles intercalated in HTiNb(Ta)O5 layered compounds. J. Catal. 2005, 231, 213–222.

24

Zhang, L. L.; Zhang, W. G.; Lu, L. D.; Yang, X. J.; Wang, X. Synthesis, structure and photocatalytic reactivity of layered CdS/H2La2Ti3O10 nanocomposites. J. Mater. Sci. 2006, 41, 3917–3921.

25

Kim, T. W.; Ha, H. W.; Paek, M. J.; Hyun, S. H.; Baek, I. H.; Choy, J. H.; Hwang, S. J. Mesoporous iron oxide–layered titanate nanohybrids: Soft-chemical synthesis, characterization, and photocatalyst application. J. Phys. Chem. C 2008, 112, 14853–14862.

26

Kim, T. W.; Hur, S. G.; Hwang, S. J.; Park, H.; Choi, W.; Choy, J. H. Heterostructured visible-light-active photocatalyst of chromia-nanoparticle–layered titanate. Adv. Funct. Mater. 2007, 17, 307–314.

27

Kim, T. W.; Hwang, S. J.; Jhung, S. H.; Chang, J. S.; Park, H.; Choi, W.; Choy, J. H. Bifunctional heterogeneous catalysts for selective epoxidation and visible light driven photolysis: Nickel oxide-containing porous nanocomposite. Adv. Mater. 2008, 20, 539–542.

28

Gu, D. E.; Yang, B. C.; Hu, Y. D. V and N co-doped nanocrystal anatase TiO2 photocatalysts with enhanced photocatalytic activity under visible light irradiation. Catal. Commun. 2008, 9, 1472–1476.

29

Matsumoto, Y.; Koinuma, M.; Iwanaga, Y.; Sato, T.; Ida, S. N doping of oxide nanosheets. J. Am. Chem. Soc. 2009, 131, 6644–6645.

30

Li, X. K.; Kikugawa, N.; Ye, J. H. Nitrogen-doped lamellar niobic acid with visible light-responsive photocatalytic activity. Adv. Mater. 2008, 20, 3816–3819.

31

Liu, G.; Wang, L. Z.; Sun, C. H.; Chen, Z. G.; Yan, X. X.; Cheng, L.; Cheng, H. M.; Lu, G. Q. Nitrogen-doped titania nanosheets towards visible light response. Chem. Commun. 2009, 1383–1385.

32

Takagaki, A.; Sugisawa, M.; Lu, D. L.; Kondo, J. N.; Hara, M.; Domen, K.; Hayashi, S. Exfoliated nanosheets as a new strong solid acid catalyst. J. Am. Chem. Soc. 2003, 125, 5479–5485.

33

Hou, W. H.; Ma, J.; Yan, Q. J.; Fu, X. C. Highly thermostable, porous, layered titanoniobate pillared by silica. J. Chem. Soc. Chem. Commun. 1993, 1144–1145.

34

Lee, S. H.; Yamasue, E.; Ishihara, K. N.; Okumura, H. Photocatalysis and surface doping states of N-doped TiOx films prepared by reactive sputtering with dry air. Appl. Catal. B 2010, 93, 217–226.

35

Bisutti, I.; Hilke, I.; Raessler, M. Determination of total organic carbon—An overview of current methods. TrAC Trends Anal. Chem. 2004, 23, 716–726.

36

Sasaki, T.; Watanabe, M. Osmotic swelling to exfoliation. Exceptionally high degrees of hydration of a layered titanate. J. Am. Chem. Soc. 1998, 120, 4682–4689.

37

Kruk, M.; Jaroniec, M. Gas adsorption characterization of ordered organic–inorganic nanocomposite materials. Chem. Mater. 2001, 13, 3169–3183.

38

Rodriguez, J. A.; Jirsak, T.; Liu, G.; Hrbek, J.; Dvorak, J.; Maiti, A. Chemistry of NO2 on oxide surfaces: Formation of NO3 on TiO2(110) and NO2–O vacancy interactions. J. Am. Chem. Soc. 2001, 123, 9597–9605.

39

Cong, Y.; Zhang, J. L.; Chen, F.; Anpo, M. Synthesis and characterization of nitrogen-doped TiO2 nanophotocatalyst with high visible light activity. J. Phys. Chem. C 2007, 111, 6976–6982.

40

Fang, J.; Wang, F.; Qian, K.; Bao, H. Z.; Jiang, Z. Q.; Huang, W. X. Bifunctional N-doped mesoporous TiO2 photocatalysts. J. Phys. Chem. C 2008, 112, 18150–18156.

41

Diwald, O.; Thompson, T. L.; Zubkov, T.; Goralski, E. G.; Walck, S. D.; Yates, J. T. Photochemical activity of nitrogen-doped rutile TiO2(111) in visible light. J. Phys. Chem. B 2004, 108, 6004–6008.

42

Shao, G. S.; Wang, F. Y.; Ren, T. Z.; Liu, Y. P.; Yuan, Z. Y. Hierarchical mesoporous phosphorus and nitrogen doped titania materials: Synthesis, characterization and visible-light photocatalytic activity. Appl. Catal. B 2009, 92, 61–67.

43

Jeong, J. J.; Lee, C. M. Effects of post-deposition annealing on the mechanical and chemical properties of the Si3N4/NbN multilayer coatings. Appl. Surf. Sci. 2003, 214, 11–19.

44

Yuan, J.; Chen, M. X.; Shi, J. W.; Shangguan, W. F. Preparations and photocatalytic hydrogen evolution of N-doped TiO2 from urea and titanium tetrachloride. Int. J. Hydrogen Energy 2006, 31, 1326–1331.

45

Serpone, N. Is the band gap of pristine TiO2 narrowed by anion- and cation-doping of titanium dioxide in second-generation photocatalysts? J. Phys. Chem. B 2006, 110, 24287–24293.

46

Liu, G.; Wang, L. Z.; Yang, H. G.; Cheng, H. M.; Lu, G. Q. Titania-based photocatalysts—crystal growth, doping and heterostructuring. J. Mater. Chem. 2010, 20, 831–843.

47

Liu, G.; Wang, L. Z.; Sun, C. H.; Yan, X. X.; Wang, X. W.; Chen, Z. G.; Smith, S. C.; Cheng, H. M.; Lu, G. Q. Band-to-band visible-light photon excitation and photoactivity induced by homogeneous nitrogen doping in layered titanates. Chem. Mater. 2009, 21, 1266–1274.

48

Li, X. K.; Kikugawa, N.; Ye, J. H. A comparison study of rhodamine B photodegradation over nitrogen-doped lamellar niobic acid and titanic acid under visible-light irradiation. Chem. Eur. J. 2009, 15, 3538–3545.

49

Chen, C. C.; Zhao, W.; Li, J. Y.; Zhao, J. C. Formation and identification of intermediates visible-light-assisted photo-degradation sulforhodamine-B dye in aqueous TiO2 dispersion. Environ. Sci. Technol. 2002, 36, 3604–3611.

50

Fuerte, A.; Hernandez-Alonso, M. D.; Maira, A. J.; Martinez-Arias, A.; Fernandez-Garcia, M.; Conesa, J. C.; Soria, J. Visible light-activated nanosized doped-TiO2 photocatalysts. Chem. Commun. 2001, 2718–2719.

51

Chen, C. C.; Zhao, W.; Lei, P. X.; Zhao, J. C.; Serponer, N. Photosensitized degradation of dyes in polyoxometalate solutions versus TiO2 dispersions under visible-light irradiation: Mechanistic implications. Chem. Eur. J. 2004, 10, 1956–1965.

52

Shimizu, K.; Tsuji, Y.; Hatamachi, T.; Toda, K.; Kodama, T.; Sato, M.; Kitayama, Y. Photocatalytic water splitting on hydrated layered perovskite tantalate A2SrTa2O7·nH2O (A = H, K, and Rb). Phys. Chem. Chem. Phys. 2004, 6, 1064–1069.

53

Rajeshwar, K.; Osugi, M. E.; Chanmanee, W.; Chentha-marakshan, C. R.; Zanoni, M. V. B.; Kajitvichyanukul, P.; Krishnan-Ayer, R. Heterogeneous photocatalytic treatment of organic dyes in air and aqueous media. J. Photochem. Photobiol. C 2008, 9, 171–192.

54

Konstantinou, I. K.; Albanis, T. A. TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations—A review. Appl. Catal. B 2004, 49, 1–14.

Publication history
Copyright
Acknowledgements

Publication history

Received: 25 January 2011
Revised: 26 February 2011
Accepted: 01 March 2011
Published: 25 March 2011
Issue date: July 2011

Copyright

© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2011

Acknowledgements

Acknowledgements

The authors greatly appreciate the financial support of the National Natural Science Foundation of China (Grant Nos. 21073084 and 20773065), the National Basic Research Program (973 Project) (Grant No. 2007CB936302) and the Modern Analysis Center of Nanjing University.

Return