Open Access
Issue
Published:
01 March 2011
CdSe Quantum Dot-Sensitized Au/TiO2 Hybrid Mesoporous Films and Their Enhanced Photoelectrochemical Performance
),
Jin Z. Zhang2(
)
Download citation
551
Views
14
Downloads
81
Crossref
N/A
WoS
83
Scopus
6
CSCD
Novel CdSe quantum dot (QD)-sensitized Au/TiO2 hybrid mesoporous films have been designed, fabricated, and evaluated for photoelectrochemical (PEC) applications. The Au/TiO2 hybrid structures were made by assembly of Au and TiO2 nanoparticles (NPs). A chemical bath deposition method was applied to deposit CdSe QDs on TiO2 NP films with and without Au NPs embedded. We observed significant enhancements in photocurrent for the film with Au NPs, in the entire spectral region we studied (350–600 nm). Incident-photon-to-current efficiency (IPCE) data revealed an average enhancement of 50%, and the enhancement was more significant at short wavelength. This substantially improved PEC performance is tentatively attributed to the increased light absorption of CdSe QDs due to light scattering by Au NPs. Interestingly, without QD sensitization, the Au NPs quenched the photocurrent of TiO2 films, due to the dominance of electron trapping over light scattering by Au NPs. The results suggest that metal NPs are potentially useful for improving the photoresponse in PEC cells and possibly in other devices such as solar cells based on QD-sensitized metal oxide nanostructured films. This work demonstrates that metal NPs can serve as light scattering centers, besides functioning as photo-sensitizers and electron traps. The function of metal NPs in a particular nanocomposite film is strongly dependent on their structure and morphology.
menu
CdSe Quantum Dot-Sensitized Au/TiO2 Hybrid Mesoporous Films and Their Enhanced Photoelectrochemical Performance
), Jin Z. Zhang2(
)
Abstract
Novel CdSe quantum dot (QD)-sensitized Au/TiO2 hybrid mesoporous films have been designed, fabricated, and evaluated for photoelectrochemical (PEC) applications. The Au/TiO2 hybrid structures were made by assembly of Au and TiO2 nanoparticles (NPs). A chemical bath deposition method was applied to deposit CdSe QDs on TiO2 NP films with and without Au NPs embedded. We observed significant enhancements in photocurrent for the film with Au NPs, in the entire spectral region we studied (350–600 nm). Incident-photon-to-current efficiency (IPCE) data revealed an average enhancement of 50%, and the enhancement was more significant at short wavelength. This substantially improved PEC performance is tentatively attributed to the increased light absorption of CdSe QDs due to light scattering by Au NPs. Interestingly, without QD sensitization, the Au NPs quenched the photocurrent of TiO2 films, due to the dominance of electron trapping over light scattering by Au NPs. The results suggest that metal NPs are potentially useful for improving the photoresponse in PEC cells and possibly in other devices such as solar cells based on QD-sensitized metal oxide nanostructured films. This work demonstrates that metal NPs can serve as light scattering centers, besides functioning as photo-sensitizers and electron traps. The function of metal NPs in a particular nanocomposite film is strongly dependent on their structure and morphology.
References(43)
Fujishima, A.; Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature 1972, 238, 37–38.
Khaselev, O.; Turner, J. A. A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splitting. Science 1998, 280, 425–427.
Bak, T.; Nowotny, J.; Rekas, M.; Sorrell, C. C. Photo-electrochemical hydrogen generation from water using solar energy. Materials-related aspects. Int. J. Hydrogen energy 2002, 27, 991–1022.
Hagfeldt, A.; Gratzel, M. Light-induced redox reactions in nanocrystalline systems. Chem. Rev. 1995, 95, 49–68.
Murphy, A. B.; Barnes, P. R. F.; Randeniya, L. K.; Plumb, I. C.; Grey, I. E.; Horne, M. D.; Glasscock, J. A. Efficiency of solar water splitting using semiconductor electrodes. Int. J. Hydrogen Energy 2006, 31, 1999–2017.
Rajeshwar, K. Hydrogen generation at irradiated oxide semiconductor-solution interfaces. J. Appl. Electrochem. 2007, 37, 765–787.
Santato, C.; Odziemkowski, M.; Ulmann, M.; Augustynski, J. Crystallographically oriented mesoporous WO3 films: Synthesis, characterization, and applications. J. Am. Chem. Soc. 2001, 123, 10639–10649.
Wolcott, A.; Kuykendall, T. R.; Chen, W.; Chen, S. W.; Zhang, J. Z. Synthesis and characterization of ultrathin WO3 nanodisks utilizing long-chain poly(ethylene glycol) J. Phys. Chem. B 2006, 110, 25288–25296.
Park, J. H.; Kim, S.; Bard, A. J. Novel carbon-doped TiO2 nanotube arrays with high aspect ratios for efficient solar water splitting. Nano Lett. 2006, 6, 24–28.
Ahn, K. S.; Yan, Y. F.; Lee, S. H.; Deutsch, T.; Turner, J.; Tracy, C. E.; Perkins, C. L.; Al-Jassim, M. Photoelectrochemical properties of N-incorporated ZnO films deposited by reactive RF magnetron sputtering. J. Electrochem. Soc. 2007, 154, B956–B959.
Wolcott, A.; Smith, W. A.; Kuykendall, T. R.; Zhao, Y. P.; Zhang, J. Z. Photoelectrochemical water splitting using dense and aligned TiO2 nanorod arrays. Small 2009, 5, 104–111.
Choi, W.; 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.
Asahi, R.; Morikawa, T.; Ohwaki, T.; Aoki, K.; Taga, Y. Visible-light hotocatalysis in nitrogen-doped titanium oxides. Science 2001, 293, 269–271.
Torres, G. R.; Lindgren, T.; Lu, J.; Granqvist, C. G.; Lindquist, S. E. Photoelectrochemical study of nitrogen-doped titanium dioxide for water oxidation. J. Phys. Chem. B 2004, 108, 5995–6003.
Qiu, X. F.; Zhao, Y. X.; Burda, C. Synthesis and characterization of nitrogen-doped group IVB visible-light-photoactive metal oxide nanoparticles. Adv. Mater. 2007, 19, 3995–3999.
Hensel, J.; Wang, G. M.; Li, Y.; Zhang, J. Z. Synergistic effect of CdSe quantum dot sensitization and nitrogen doping of TiO2 nanostructures for photoelectrochemical solar hydrogen generation. Nano Lett. 2010, 10, 478–483.
Chen, Z. H.; Tang, Y. B.; Liu, C. P.; Leung, Y. H.; Yuan, G. D.; Chen, L. M.; Wang, Y. Q.; Bello, I.; Zapien, J. A.; Zhang, W. J.; Lee, C. S.; Lee, S. T. Veertically aligned ZnO nanorod arrays sentisized with gold nanoparticles for Schottky barrier photovoltaic cells. J. Phys. Chem. C 2009, 113, 13433–13437.
Tak, Y.; Hong, S. J.; Lee, J. S.; Yong, K. Fabrication of ZnO/CdS core/shell nanowire arrays for efficient solar energy conversion. J. Mater. Chem. 2009, 19, 5945–5951.
Derkacs, D.; Lim, S. H.; Matheu, P.; Mar, W.; Yu, E. T. Improved performance of amorphous silicon solar cells via scattering form surface plasmon polaritons in nearby metallic nanoparticles. Appl. Phys. Lett. 2006, 89, 093103.
Pillai, S.; Catchpole, K. R.; Trupke, T.; Green, M. A. Surface plasmon enhanced silicon solar cells. J. Appl. Phys. 2007, 101, 093105.
Nakato, Y.; Shioji, M.; Tsubomura, H. Photoeffects on the potentials of thin metal films on a n-TiO2 crystal wafer. The mechanism of semiconductor phtocatalysts. Chem. Phys. Lett. 1982, 90, 453–456.
Zhao, G. L.; Kozuka, H.; Yoko, T. Photoelectrochemical properties of dye-sensitized TiO2 films containing dispersed gold metal particles prepared by sol-gel method. J. Ceramic Soc. Jan 1996, 104, 164–168.
Chandrasekharan, N.; Kamat, P. V. Improved the photoelectrochemical performance of nanostructured TiO2 films by adsorption of gold nanoparticles. J. Phys. Chem. B 2000, 104, 10851–10857.
Tian, Y.; Tatsuma, T. Mechanisms and applications of plasmon-induced charge separation at TiO2 films loaded with gold nanopaticles. J. Am. Chem. Soc. 2005, 127, 7632–7637.
Tian, Y.; Tatsuma, T. Plasmon-induced photoelectrochemistry at metal nanoparticles supported on nanoporous TiO2. Chem. Commun. 2004, 1810–1811.
Nishijima, Y.; Ueno, K.; Yokota, Y.; Murakoshi, K.; Misawa, H. Plasmon-assisted photocurrent generation from visible to near-infrared wavelength using a Au-nanorods/TiO2 electrode. J. Phys. Chem. Lett. 2010, 1, 2031–2036.
Dawson, A.; Kamat, P. V. Semiconductor-metal nanocomposites. Photoinduced fusion and photocatalysis of gold-capped TiO2 (TiO2/gold) nanoparticles. J. Phys. Chem. B 2001, 105, 960–966.
Subramanian, V.; Wolf, E.; Kamat, P. V. Semiconductormetal composite nanostructures. To what extent do metal nanoparticles improve the photocatalytic activity of TiO2 films. J. Phys. Chem. B 2001, 105, 11439–11446.
Schaadt, D. M.; Feng, B.; Yu, E. T. Enhanced semiconductor optical absorption via surface plasmon excitation in metal nanoparticles. Appl. Phys. Lett. 2005, 86, 063106.
Catchpoleand, K. R.; Polman, A. Design principles for particle plasmon enhanced solar cells. Appl. Phys. Lett. 2008, 93, 191113.
Nakayama, K.; Tanabe, K.; Atwater, H. A. Plasmonic nanoparticle enhanced light absorption in GaAs solar cells. Appl. Phys. Lett. 2008, 93, 121904.
Smith, W.; Mao, S.; Lu, G. H.; Catlett, A.; Chen, J. H.; Zhao, Y. P. The effect of Ag nanoparticle loading on the photocatalytic activity of TiO2 nanorod arrays. Chem. Phys. Lett. 2010, 485, 171–175.
Zhang, J. Z.; Noguez, C. Plasmonic optical properties and applications of metal nanostructures. Plasmonics 2008, 3, 127–150.
Bai, F.; Wang, D. S.; Huo, Z. Y.; Chen, W.; Liu, L. P.; Liang, X.; Chen, C.; Wang, X.; Peng, Q.; Li, Y. D. A versatile bottom-up assembly approach to colloidal Spheres from nanocrytstals. Angew. Chem. Int. Ed. 2007, 46, 6650–6653.
Liu, L. P.; Hensel, J.; Fitzmorris, R. C.; Li, Y. D.; Zhang, J. Z. Preparation and photoelectrochemical properties of CdSe/TiO2 hybrid mesoporous structures. J. Phys. Chem. Lett. 2010, 1, 155–160.
Lokhande, C. D.; Lee, E. H.; Jung, K. D.; Joo, O. S. Ammonia-free chemical bath method for deposition of microcrystalline cadmium selenide films. Mater. Chem. Phys. 2005, 91, 200–204.
Li, X. L.; Peng, Q.; Yi, J. X.; Wang, X.; Li, Y. D. Near monodisperse TiO2 nanoparticles and nanorods. Chem. Eur. J. 2006, 12, 2383–2391.
Liu, J. F.; Chen, W.; Liu, X. W.; Zhou, K. B.; Li, Y. D. Au/LaVO4 nanocomposite: Preparation, characterization, and catalytic activity for CO oxidation. Nano Res. 2008, 1, 46–55.
Ahmadi, T. S.; Logunov, S. L.; El-Sayed, M. A. Picosecond dynamics of colloidal gold nanoparticles. J. Phys. Chem. 1996, 100, 8053–8056.
Zhang, J. Z. Ultrafast studies of electron dynamics in semiconductor and metal colloidal nanoparticles: Effects of size and surface. Acc. Chem. Res. 1997, 30, 423–429.
Subramanian, V.; Wolf, E. E.; Kamat, P. V. Green emission to probe photoinduced charging events in ZnO–Au nanoparticles. Charge distribution and Fermi-level equilibration. J. Phys. Chem. B 2003, 107, 7479–7485.
Jakob, M.; Levanon, H.; Kamat, P. V. Charge distribution between UV-irradiated TiO2 and gold nanoparticles: Determination of shift in the Fermi level. Nano Lett. 2003, 3, 353–358.
Publication history
Copyright
Acknowledgements
LLP would like to thank the Chinese Scholarship Council (CSC) for financial aid. YL gratefully acknowledges the support of a US National Science Foundation CAREER award (No. DMR-0847786). YDL would like to thank the National Natural Science Foundation of China (No. 90606006) for financial support. JZZ is grateful to the Basic Energy Sciences Division of the US Department of Energy (DOE) (No. 05ER4623A00) for financial support.
Rights and permissions
This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
FEEDBACK 
TOP