The study of the photosensitive materials used in solar-hydrogen energy by a versatile photoelectrochemical cell (original) (raw)
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TiO2based systems for photoelectrochemical generation of solar hydrogen
Journal of Physics: …, 2009
In the present work our attention was focused on the obtaining photoelectrodes for photoelectrochemical cell (PEC) that incorporate two electrodes, one of which has been titania (TiO 2 ) coated on a transparent conducting oxide (TCO), referred to as the primary electrode and the other, the counter electrode, a non-corrosive metal such as a thin layer of platinum. A thin layer of a nanoporous TiO 2 semiconductor was deposited onto a sheet of ITO conducting glass (sheet resistance ~ 30 cm -2 ). Several complementary investigation techniques like BET, SEM and XRD were used to follow the influence of the reactants molar ratio and thermal treatment on the TiO 2 photoanode. The nanocrystalline TiO 2 /ITO conducting glass electrode seems to be a promising photoanode in a photoelectrochemical PEC cell for hydrogen generation by water splitting.
In the present work our attention was focused on the obtaining photoelectrodes for photoelectrochemical cell that incorporate two electrodes, one of which has been titania (TiO 2 ) coated on a transparent conducting oxide (TCO), referred to as the primary electrode and the other, the counter electrode, a non-corrosive metal such as a thin layer of platinum. A thin layer of a nanoporous TiO 2 semiconductor was deposited onto a sheet of ITO conducting glass (sheet resistance ~ 30 Ωcm -2 ). Several complementary investigation techniques like BET, SEM and XRD were used to follow the influence of the reactants molar ratio and thermal treatment on the TiO 2 photoanode. The nanocrystalline TiO 2 /ITO conducting glass electrode seems to be a promising photoanode in a photoelectrochemical cell for hydrogen generation by water splitting.
Journal of Physics Conference Series 09/2009; 182(1):012080. DOI:DOI:10.1088/1742-6596/182/1/012080 , 2009
Abstract. It was built a versatile photoelectrochemical cell devoted to the comparative study of the photosensitive materials used as photoelectrodes in solar-hydrogen production. The experimental arrangement make possible a relative evaluation of the electrodes properties by the measurement of the electric parameters, giving directly I = f (U) for the cell electric circuit with and without an external electrical bias. It also gives a direct measurement of the volume of the evolved gases, and an on-line analyze of the gases by the coupled gas chromatograph, or of-line, by a mass spectrometer.
Vh A Photoelectrochemical Solar Cell Employing a TiO, Anode and Oxygen Cathode
2009
A photoelectrochemical cell for conversion of light to electrical energy based on the photosensitized oxidation of water at a chemically vapor deposited, thin film, n-type TiO2 anade and the reduction of oxygen at a fuel cell-type cathode is described. The effect of load resistance on the current, cell voltage, and power was studied, and quantum and power efficiencies under short-circuit conditions for monochromatic light of about 365 nm was estimated as 26% and 1-2%, respectively. Open-circuit cell voltages of 0.89V were obtained. The cell is simple to construct and is capable oK continuous operation with no apparent deterioration in performance. Photoeffects at semiconductor electrodes received renewed attention when these materials were recognized as potential candidates for use in the conversion of light to electrical and chemical energy via some electrochemical process; this subject has been reviewed and discussed recently (1, 2). Of special interest are semiconductor electrode...
Study of N-doped TiO2 thin films for photoelectrochemical hydrogen generation from water
Open Chemistry, 2015
The present work deals with nitrogen-doped stoichiometric TiO2:N and non-stoichiometric TiO2−x:N thin films deposited by means of dc-pulsed reactive sputtering for application as photoanodes for hydrogen generation from water, using solar energy. Stoichiometric thin films of TiO2 crystallize as a mixture of anatase and rutile while rutile phase predominates in TiO2:N at higher nitrogen flow rates as shown by X-ray diffraction at grazing incidence, XRD GID. Lack of bulk nitridation of stoichiometric TiO2:N is indicated by valence-to-core X-ray emission spectroscopy, XES, analysis. The energy band gap as well as flat band potential remain almost unaffected by increasing nitrogen flow rate in this case. In contrast to that, non-stoichiometric thin films of TiO2‑x:N demonstrate systematic evolution of the structural, morphological, optical and photolectrochemical properties upon increasing level of nitrogen doping. Pronounced changes in the growth pattern of non-stoichiometric TiO2-x:N ...
A study of S-doped TiO2 for photoelectrochemical hydrogen generation from water
Journal of Materials Science, 2008
Sulfur-doped titanium dioxide (TiO 2 ) was investigated as a potential catalyst for photoelectrochemical hydrogen generation. Three preparation techniques were used: first ballmilling sulfur powder with Degussa P25 powder (P25), second, ball milling thiourea with P25, and third a sol-gel technique involving titanium (IV) butoxide and thiourea. The resulting powders were heat-treated and thin-film electrodes were prepared. In all three cases, the heat-treated powders contained small amounts of S (1-3%). However, Rietveld analysis on X-ray diffraction (XRD) measurements revealed no significant changes in lattice parameters. For the samples prepared using thiourea, X-ray photoelectron spectroscopy (XPS) measurements indicated the presence of N and C in the heat-treated powders in addition to S. In all cases, visible-ultraviolet spectroscopy performed on bulk powders confirmed the extension of absorption into the visible region. However, the same spectroscopic technique performed on thin-film electrodes (*0.5 lm) suggests that the absorption coefficients were very small in the visible region (B10 4 m -1 ). The first and third methods yielded powders with substantially smaller photocatalytic activity relative to P25 powder in the UV region. The electrodes prepared from powders obtained using the second method yielded photocurrents comparable to those prepared from P25 powder.
This paper reports the investigations on the optimization of nanostructured TiO2 with respect to optimum photoelectrode area for modular design of photoelectrolysis cell. This was done for determining the electrode area for optimum electrical output and hydrogen production rate. The nanostructured TiO2 has been formed by hydrolysis of titanium tetraisopropoxide Ti[OCH(CH3)2]4 followed by the deposition with spin on technique. The photoelectrochemical cell having nanostructured TiO2 photoanode of several geometricareas, namely, 0.21, 0.50, 0.72, 1.47 and 1:85 cm2, were fabricated and characterized. It has been found that the photoanode area corresponding to optimum electrical output and hydrogen production rate corresponds to ∼ 0:5 c m2.
International Journal of Hydrogen Energy, 1999
A new photoelectrode system TiO 1 "ns#ÐVO 1 for photoassisted electrolysis of water is described[ The nanostructured TiO 1 photoelectrode was prepared by the hydrolysis of titanium!tetraisopropoxide followed by deposition of thin _lm by spin coating[ To prepare the TiO 1 "ns#ÐVO 1 photoelectrode\ vanadium _lm was deposited on the TiO 1 "ns# _lm and subsequently oxidized in O 1 ambient[ The TiO 1 "ns#ÐVO 1 photoelectrode exhibited enhanced photovoltage and photocurrent of 579 mV and 00[9 mA cm −1 \ respectively\ whereas the TiO 1 "ns# presented 439 mV and 2[1 mA cm −1 \ respectively[ X!ray and S[E[M studies were carried out to monitor the surface and bulk characteristics of the TiO 1 "ns#Ð VO 1 photoelectrode[ The rate of hydrogen production under photoelectrolysis was found to be 5 l h −0 m −1 for the TiO 1 "ns# and ½02[9 l h −0 m −1 for the TiO 1 "ns#ÐVO 1 photoelectrode[ The TiO 1 "ns# photoelectrode shows the improvement in the PEC characteristics due to higher quantum yield resulting from the structured nature of the material[ The PEC improvement in the TiO 1 "ns#ÐVO 1 photoelectrode is due to the increase of range of absorption and the decrease of energy gap[