Photoelectrochehical studies on the mixed oxides,SrTiO3,Sr2TiO4 and Sr3Ti2O7
TL;DR: PEC studies on two members of the homologous series, Sr2TiO4 and Sr3Ti2O7, have been carried out and the results compared to the behaviour of SrTiO3 as mentioned in this paper.
About: This article is published in Materials Chemistry and Physics.The article was published on 1986-04-01. It has received 16 citations till now. The article focuses on the topics: Band gap.
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TL;DR: In this paper, a composite Sr2TiO4/SrTiO3(La,Cr) heterojunction photocatalyst has been prepared by a simple in situ polymerized complex method.
Abstract: A composite Sr2TiO4/SrTiO3(La,Cr) heterojunction photocatalyst has been prepared by a simple in situ polymerized complex method. Upon Pt cocatalyst loading, this catalyst shows higher photocatalytic activity towards hydrogen production than individual SrTiO3(La,Cr) and Sr2TiO4(La,Cr) in the presence of methanol sacrificial reagent. Microscopic morphology studies show that well defined heterojunctions are formed by matching the lattice fringes of SrTiO3(La,Cr) and Sr2TiO4(La,Cr), and Pt was preferentially loaded on the surface of the Sr2TiO4(La,Cr) component in the composite Sr2TiO4/SrTiO3(La,Cr) photocatalyst. XPS and EPR analyses show that the composite photocatalyst also has the lowest amount of Cr6+ electron trapping sites. Band structure analysis by combining absorption spectroscopy and Mott–Schottky plots shows that, in the composite photocatalyst, the photogenerated electrons and holes tend to migrate from SrTiO3(La,Cr) to Sr2TiO4(La,Cr) and from Sr2TiO4(La,Cr) to SrTiO3(La,Cr), respectively. This kind of band structure can facilitate charge transfer and separation driven by the minor potential difference between the two components, which is further confirmed by the observation of long lived electrons in the time resolved FT-IR spectroscopic study. It is concluded that the superior photocatalytic activity of the composite heterojunction photocatalyst is due to efficient charge transfer and separation by well defined heterojunctions formed between SrTiO3(La,Cr) and Sr2TiO4(La,Cr), preferential loading of Pt nanoparticles on the Sr2TiO4(La,Cr) component, and the lowest amount of Cr6+ in the composite photocatalyst. The tailored design and synthesis of the composite heterojunction structure is a promising approach for the improvement of the photocatalytic activity of a photocatalyst.
108 citations
TL;DR: In this article, the photocatalytic degradation in the presence of nanosized $GdCoO_3$ oxides was carried out on dyes, phenols, and substituted phenols.
Abstract: $GdCoO_3$ nanoparticles with sizes of 3, 12, and 200 nm were prepared from single source mixed-metal organic framework (MOF) precursor, $[Gd(H_2O)_3Co\{C_5N_1H_3(COO)_2\}_3]$. The photocatalytic degradation studies, carried out for the first time in the presence of nanosized $GdCoO_3$ oxides, on dyes, phenols, and substituted phenols indicate favorable activity. The intermediates formed during the photocatalytic reactions were analyzed, and possible reaction mechanisms have been proposed. The results of the present study indicate that the degradation appear to be faster in the presence of 3 nm $GdCoO_3$ compared to P-25 Degussa $TiO_2$ catalyst. The reduced formation of unwanted intermediates in the presence of $GdCoO_3$ indicates that this material would prove to be a good photocatalyst in environmental photocatalysis.
80 citations
TL;DR: In this paper, a brief survey of the historical development of photoelectrochemical solar cells is given, and the principle and future of solar chargeable battery is compared with a wet and a dry type photovoltaic cell.
54 citations
TL;DR: In this paper, the p-type as grown single crystals of the layered compounds FePS3 and FePSe3 have been studied by the photoelectrochemical method and the currentvoltage and capacitance-voltage characteristics indicate the presence of surface states.
16 citations
TL;DR: In this paper, the fine crystal structure change of perovskite catalysts has been investigated and it is found that the moderate and strong surface basic sites contribute vitally to the reaction.
10 citations
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TL;DR: In this article, the behavior of semiconducting electrodes for photoelectrolysis of water is examined in terms of the physical properties of the semiconductor and the photocurrent is described using a simple Schottky barrier.
Abstract: The behavior of semiconducting electrodes for photoelectrolysis of water is examined in terms of the physical properties of the semiconductor. The semiconductor‐electrolyte junction is treated as a simple Schottky barrier, and the photocurrent is described using this model. The approach is appropriate since large‐band‐gap semiconductors have an intrinsic oxygen overpotential which removes the electrode reaction kinetics as the rate‐limiting step. The model is successful in describing the wavelength and potential dependence of the photocurrent in WO3 and allows a determination of the band gap, optical absorption depth, minority‐carrier diffusion length, flat‐band potential, and the nature of the fundamental optical transition (direct or indirect). It is shown for WO3 that minority‐carrier diffusion plays a limited role in determining the photoresponse of the semiconductor‐electrolyte junction. There are indications that the diffusion length in this low carrier mobility material is determined by diffusion‐controlled bulk recombination processes rather than the more common trap‐limited recombination. It is also shown that the fundamental optical transition is indirect and that the band‐gap energy depends relatively strongly on applied potential and electrolyte. This effect seems to be the result of field‐induced crystallographic distortions in antiferroelectric WO3.
1,758 citations
1,131 citations
TL;DR: The electron affinities of metal oxide semiconductors that have been used as anodes in photoelectrochemical cells are calculated using the atomic electronegativities of the constituent atoms as mentioned in this paper.
Abstract: The electron affinities of several metal oxide semiconductors that have been used as anodes in photoelectrochemical cells are calculated using the atomic electronegativities of the constituent atoms. These electron affinities are quantitatively related to the measured flatband potentials by considering the effects of specific adsorption of potential‐determining ions (for metal oxides used in photoelectrolysis, these are usually OH− and H+). Methods are discussed for determining the pH at which net adsorbed surface charge and thus potential across the Helmholtz layer is zero (point of zero zeta potential, pzzp). This pH value is shown to correlate with the electronegativity of the metal oxides. The application of these ideas to other semiconductor‐electrolyte systems is discussed.
1,078 citations
905 citations
TL;DR: In this paper, a wide range of oxides were examined for use as anodes in photoelectrochemical cells for the conversion of solar energy into electrical power or hydrogen, and the Schottky barrier model of the semi-conductor-electrolyte interface was used throughout.
710 citations