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Photoelectrochemical response

Si H-Y, Sun Z-H, Zhang H-L (2008) Photoelectrochemical response from CdSe-sensitized anodic oxidation Ti02 nanotubes. Colloids Surf A 313-314 604-607... [Pg.308]

Magnetic field effects on photoelectrochemical responses of modified electrodes with porphyrin-viologen linked compound as a Langmuir-Blodgett film. Chem. Lett., 661—662. [Pg.276]

Nanoporous T102 and WO3 films by anodization of titanium and tungsten substrates Influence of process variables on morphology and photoelectrochemical response. J Phys Chem B 110 25347-25355... [Pg.354]

Ruan C, Paulose M, Vargbese OK, Grimes CA (2006) Enhanced photoelectrochemical response in highly ordered Ti02 nanotube arrays anodized in boric acid containing electrolyte. Solar Energy Materials Solar Cells 90 1283-1295... [Pg.362]

While many of the standard electroanalytical techniques utilized with metal electrodes can be employed to characterize the semiconductor-electrolyte interface, one must be careful not to interpret the semiconductor response in terms of the standard diagnostics employed with metal electrodes. Fundamental to our understanding of the metal-electrolyte interface is the assumption that all potential applied to the back side of a metal electrode will appear at the metal electrode surface. That is, in the case of a metal electrode, a potential drop only appears on the solution side of the interface (i.e., via the electrode double layer and the bulk electrolyte resistance). This is not the case when a semiconductor is employed. If the semiconductor responds in an ideal manner, the potential applied to the back side of the electrode will be dropped across the internal electrode-electrolyte interface. This has two implications (1) the potential applied to a semiconducting electrode does not control the electrochemistry, and (2) in most cases there exists a built-in barrier to charge transfer at the semiconductor-electrolyte interface, so that, electrochemical reversible behavior can never exist. In order to understand the radically different response of a semiconductor to an applied external potential, one must explore the solid-state band structure of the semiconductor. This topic is treated at an introductory level in References 1 and 2. A more complete discussion can be found in References 3, 4, 5, and 6, along with a detailed review of the photoelectrochemical response of a wide variety of inorganic semiconducting materials. [Pg.856]

Figure 5.51 Applied potential dependence on the photocurrent intensities of RUC7VCeS / Au (O), RuCsVCgS/Au ( ), RuC17S/Au ( ) and RuC13S/Au ( ) electrodes Xex, 470 nm [TEOA] = 5 x 10-2 M [NaC104] = 0.1 M. Reprinted from Thin Solid Films, 350, Y. Koide,N. Terasaki,T. Akiyama and S. Yamada, Effects of spacer-chain length on the photoelectrochemical responses of mono-layer assemblies with ruthenium tris(2,2 -bipyridine)-viologen linked disulfides, 223-227, Copyright (1999), with permission from Elsevier Science... Figure 5.51 Applied potential dependence on the photocurrent intensities of RUC7VCeS / Au (O), RuCsVCgS/Au ( ), RuC17S/Au ( ) and RuC13S/Au ( ) electrodes Xex, 470 nm [TEOA] = 5 x 10-2 M [NaC104] = 0.1 M. Reprinted from Thin Solid Films, 350, Y. Koide,N. Terasaki,T. Akiyama and S. Yamada, Effects of spacer-chain length on the photoelectrochemical responses of mono-layer assemblies with ruthenium tris(2,2 -bipyridine)-viologen linked disulfides, 223-227, Copyright (1999), with permission from Elsevier Science...
The semiconductor nature of diamond manifests itself in a photoelectrochemical response caused by the photogeneration of free charge carriers. With the dielectric diamond, photoconductance (that is, an increase in the conductance due to an increase in majority carrier concentration) can be observed. With the conducting... [Pg.257]

M. Fujihira, K. Nishiyama, H. Yamada, Photoelectrochemical Responses of Optically Transparent Electrodes Modified with Langmuir-Blodgett Films Consisting of Surfactant Derivatives of Electron-Donor, Acceptor and Sensitizer Molecules , Thin Solid Films, 132,77 (1985)... [Pg.173]

There are two possible excited state interfacial electron transfer processes that can occur from a molecular excited state, S, created at a metal surface (a) the metal accepts an electron from S to form S+ or (b) the metal donates an electron to S to form S . Neither of these processes has been directly observed. The two processes would be competitive and unless there is some preference, no net charge will cross the interface. In order to obtain a steady-state photoelectrochemical response, back interfacial electron transfer reactions of S+ (or S ) to yield ground-state products must also be eliminated. Energy transfer from an excited sensitizer to the metal is thermodynamically favorable and allowed by both Forster and Dexter mechanisms [20, 21]. There exists a theoretical [20] and experimental [21] literature describing energy transfer quenching of molecular excited states by metals. How-... [Pg.2733]

To assess the suitability of the nanocrystals as optically active centers for their incorporation into optoelectronic devices, a monolayer of particles was deposited onto mercaptopropionic acid derivatized ITO substrates. Their photoelectrochemical response was assessed under conditions of illumination using LED whose peak intensity (A.pk = 470 nm) is greater than the calculated bandgap. As can be seen from the inset of Fig. 2, upon illumination of the SnS-derivatized electrode the current is observed to quickly increase and remain relatively constant during the illumination time, here 20 s, and upon switching off of the LED the current returns to its preillumination value. This photocurrent response profile is reproducible over many cycles (in a number of trials for periods in excess of an hour). An average photocurrent (current under illumination minus background current) for a number of similarly prepared electrodes has yielded values of between 6 and 8 nA cm . ... [Pg.323]

Chemical composition of the electrolyte is a particularly important parameter in PEC systems based on complex electrolytes snch as polysnlphide or ferro/ ferricyanide. In the latter redox conple, as shown in Fig. 10.8, replacement of one of the hexacyano ligands strongly changes the photoelectrochemical response of illnminated n-CdSe dne to a combination of electrochemical and spectroscopic effects (Licht, 1995), and addition of the KCN to the electrolyte can increase n-CdSe and n-CdTe photovoltages by 200 mV (Licht and Peramnnage, 1990). [Pg.607]

Summary. The importance of flie electrode surface structure in electrochemistry is briefly described. Examples are given in which the structural information provided by scanning tunneling microscopy (STM) is of assistance in clarifying the electrochemical behavior. The importance of surface structure in the photoelectrochemical response of metals is illustrated by an STM application. Finally, the potentialities of newr scanning microprobe techniques suitable for mapping local photoelectrochemical properties of metal surfaces are briefly discussed. [Pg.101]

We have developed two major systems for automated high-throughput photoelectrochemical screening designed to measure electrochemical and photoelectrochemical responses of combinatorially... [Pg.139]

Several papers have been published on the use of a photosyntheric elearochemical micro-cell " and suitable mediators, to study the generation of photo-currents and photo-potentials by photosynthetic membranes and submembrane fractions enriched with PS I and PS II. The suitability of the cell to smdy the specific behaviour of the two photosystems and their synchronized activity was verified successfully. The same technique has also been apphed to measure the photoelectrochemical response of samples illuminated ly single vravelength hght (action spectra). ... [Pg.98]

Rao KK, Hall DO, Vlachopoulos N et al. Photoelectrochemical response of photosystem II particles immobilized on Dye-derivatized Ti02 films. J Photochem Photobiol B 1990 5 379-389. [Pg.154]

N.R. Tacconi, C.R. Chenthamarakshan, G. Yogeeswaran, A. Watcharenwong, R.S. de Zoysa, N.A. Basil, K. Rajeshwar, Nanoporous Ti02 and WO3 films by anodization of titanium and tungsten substrates influence of process variables on morphology and photoelectrochemical response . Journal of Physical Chemistry B, 110(50), 25347-25355, (2006). [Pg.138]

Klofla, T.J., Sims, T.D., Pankow, J.W., Danziger,)., Nebesny, K.W., and Armstrong, N.R. (1987) Spectroscopic and photoelectrochemical studies of trivalent metal phthalocyanine thin films the role of gaseous dopants (oxygen and hydrt en) in determining photoelectrochemical response. /. Phys. Chem., 91, 5651-5659. [Pg.269]

Butcher DP Jr, Gewirth AA (2010) Photoelectrochemical response of TIVO4 and InV04 TIVO4 composite. Chem Mater 22 2555-2562... [Pg.37]

A combined optical/electrochemical microelectrode can be used as the tip to study, for example, photoelectrochemical reactions on semiconductors [60-63]. This tip consists of a several micron diameter optical fiber coated with gold and insulated with a polymer film [60]. The optical fiber creates a focused light spot on the substrate surface and the concentric gold ring serves as an electrode to monitors the products of the photoelectrochemical reaction at a substrate. If ij and (the substrate photocurrent) are acquired, it is possible to image the photoelectrochemical response... [Pg.452]

We synthesized a new series of Cgo-derivatized PTs obtained by electropolymerization of bithiophenic precursors 238 and 239 in which one or two polymerizable groups are attached to Cgo by alkyl spacers of variable length [158]. The precursor structure involves a 3,4-ethylenedioxythiophene associated with a 3-alkylsulfanylthiophene. In addition to the decrease of electropolymerization potential, the sulfide group represents a convenient way for the functionalization of thiophene by the facile deprotection of a thiolate function [159]. The analysis of the photoelectrochemical response of poly(239) (n=3) and poly(240) on platinum microelectrodes polarized at -0.10 V and irradiated with intermittent white light shows that for both the initial peak and the stabilized current, the values of photocurrent are more than twice in the case of poly(239) ( = 3). [Pg.531]

Recently, two other Ceo containing polymers have been synthesized by electropolymerization of terthiophene derivatives 241 and 242, respectively, by Komatsu [434] and Wudl [435]. The efficient photoelectrochemical response observed for poly(241) and the low bandgap in the order of 0.7 eV for poly(242) suggest that these compounds could be useful for the realization of solar cells. [Pg.532]

Fermin, D.J., H.D. Duong, Z.F. Ding, P.F. Brevet, and H.H. Girault (1999). Photo-induced electron-transfer at Uquid/hquid interfaces— part HI— Photoelectrochemical responses involving porphyrin ion-pairs. J. Am. Chem. Soc. 121,10203-10210. [Pg.570]


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Photoelectrochemical

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