TY - JOUR
T1 - Optimal Ag concentration for H2 production via Ag:TiO 2 nanocomposite thin film photoanode
AU - Naseri, N.
AU - Kim, H.
AU - Choi, W.
AU - Moshfegh, A. Z.
N1 - Funding Information:
The authors would like to thank Research and Technology Council of Sharif University of Technology for financial support. Useful assistance of Mr. S Rafiee for XPS measurements and Mrs. Vaseghinia for AFM images is greatly acknowledged.
PY - 2012/2
Y1 - 2012/2
N2 - TiO2 thin films containing different concentrations of Ag nanoparticles have been synthesized by sol-gel method. According to UV-visible spectra, presence of an intense surface plasmon resonance peak at 490 nm of wavelength indicated formation of silver nanoparticles in the TiO2 films. Based on atomic force microscopy (AFM) analysis, the surface roughness and the effective surface ratio increased by increasing the Ag mol%. Moreover, scanning electron microscopy (SEM) images showed formation of Ag nanoparticles on the surface for the samples containing high Ag concentration. X-ray diffraction (XRD) patterns revealed that the size of Ag nanocrystals increased by increasing the Ag content in the films while the nanocrystalline size of TiO2 reduced in the presence of silver nanoparticles. Based on x-ray photoelectron spectroscopy (XPS) data, a stoichiometric chemical composition was detected for TiO2 while, Ag presented in a combination a metal/oxide states on the surface. Studying photoresponse of the samples showed that the highest photocurrent was obtained for the sample containing 1 mol% Ag. By measuring the photovoltage versus time, it was found that addition of silver nanoparticles to the TiO2 layer resulted in reduction of the transient time of the photogenerated carriers in the samples. Impedance spectroscopy determined a slight decrease in charge transfer resistance by addition of Ag to the films. Moreover, measuring the amount of hydrogen produced during water splitting reactions verified that the highest quantum yield of 9.6% was obtained for the sample with 1 mol% Ag.
AB - TiO2 thin films containing different concentrations of Ag nanoparticles have been synthesized by sol-gel method. According to UV-visible spectra, presence of an intense surface plasmon resonance peak at 490 nm of wavelength indicated formation of silver nanoparticles in the TiO2 films. Based on atomic force microscopy (AFM) analysis, the surface roughness and the effective surface ratio increased by increasing the Ag mol%. Moreover, scanning electron microscopy (SEM) images showed formation of Ag nanoparticles on the surface for the samples containing high Ag concentration. X-ray diffraction (XRD) patterns revealed that the size of Ag nanocrystals increased by increasing the Ag content in the films while the nanocrystalline size of TiO2 reduced in the presence of silver nanoparticles. Based on x-ray photoelectron spectroscopy (XPS) data, a stoichiometric chemical composition was detected for TiO2 while, Ag presented in a combination a metal/oxide states on the surface. Studying photoresponse of the samples showed that the highest photocurrent was obtained for the sample containing 1 mol% Ag. By measuring the photovoltage versus time, it was found that addition of silver nanoparticles to the TiO2 layer resulted in reduction of the transient time of the photogenerated carriers in the samples. Impedance spectroscopy determined a slight decrease in charge transfer resistance by addition of Ag to the films. Moreover, measuring the amount of hydrogen produced during water splitting reactions verified that the highest quantum yield of 9.6% was obtained for the sample with 1 mol% Ag.
KW - Hydrogen generation
KW - Photocurrent density
KW - Silver nanoparticles
KW - Transient time
UR - http://www.scopus.com/inward/record.url?scp=84856586588&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2011.11.041
DO - 10.1016/j.ijhydene.2011.11.041
M3 - Article
AN - SCOPUS:84856586588
SN - 0360-3199
VL - 37
SP - 3056
EP - 3065
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
IS - 4
ER -
