Chemical reactions of electrons and holes at the ZnO/electrolyte-solution interface

Morrison, Steven; Freund, Thomas

doi:10.1016/0013-4686(68)80061-1

Cited by 52 publications

(15 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The addition of formate to the electrolyte resulted in an approximate doubling of the magnitude of the photocurrent. It is known that the one electron oxidation of formate produces a highly energetic radical that can inject electrons into the conduction band of some semiconductors, effectively doubling the current [45,46]. Kennedy and Frese have previously suggested that Small photocurrents observed at hematite single crystal and thin film electrodes have previously been attributed to short minority carrier (hole) diffusion lengths [6].…”

Section: Discussionmentioning

confidence: 99%

Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

Gardner

Kim

Searson

et al. 2011

Journal of Nanomaterials

View full text Add to dashboard Cite

Colloidal crystal templates were prepared by gravitational sedimentation of 0.5 micron polystyrene particles onto fluorine-doped tin oxide (FTO) electrodes. Scanning electron microscopy (SEM) shows that the particles were close packed and examination of successive layers indicated a predominantly face-centered-cubic (fcc) crystal structure where the direction normal to the substrate surface corresponds to the (111) direction. Oxidation of aqueous ferrous solutions resulted in the electrodeposition of ferric oxide into the templates. Removal of the colloidal templates yielded ordered macroporous electrodes (OMEs) that were the inverse structure of the colloidal templates. Current integration during electrodeposition and cross-sectional SEM images revealed that the OMEs were about 2 μm thick. Comparative X-ray diffraction and infrared studies of the OMEs did not match a known phase of ferric oxide but suggested a mixture of goethite and hematite. The spectroscopic properties of the OMEs were insensitive to heat treatments at 300• C. The OMEs were utilized for photoassisted electrochemical oxidation. A sustained photocurrent was observed from visible light in aqueous photoelectrochemical cells. Analysis of photocurrent action spectra revealed an indirect band gap of 1.85 eV. Addition of formate to the aqueous electrolytes resulted in an approximate doubling of the photocurrent.

show abstract

Section: Discussionmentioning

confidence: 99%

Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

Gardner

Kim

Searson

et al. 2011

Journal of Nanomaterials

View full text Add to dashboard Cite

show abstract

“…[24] However, in the present system, the direct e À cb reduction seems to be more advantageous than the reduction by CCH 2 OH radicals because the former proceeds on the reduction sites (Ag nanoparticle surfaces) with a high Ph-NO 2 concentration and the opposite is true for the latter [condition (2)]. CH 3 OH and (CH 3 ) 3 COH are known to act as hole-capturing agents to accelerate various TiO 2 photocatalytic reactions, [25,26] where the holes in the valence band (h þ vb ) are captured by CH 3 OH or (CH 3 ) 3 COH to yield CCH 2 OH or CCH 2 (CH 3 ) 2 COH radicals, respectively. The a-hydroxyl radical with strong reducing power can inject another electron into the conduction band of TiO 2 (current-doubling effect), whereas the latter b-hydroxyl radical does not have enough reducing power to produce such events.…”

mentioning

confidence: 99%

Kinetic and DFT Studies on the Ag/TiO₂‐Photocatalyzed Selective Reduction of Nitrobenzene to Aniline

et al. 2005

View full text Add to dashboard Cite

TiO2 particles loaded with silver nanoparticles with a mean diameter of 1.5 nm exhibit a high photocatalytic activity (84 % conversion after 1 h irradiation) for the reduction of nitrobenzene to aniline with 100 % selectivity in the presence of CH3OH (concentration=100 mM). High-resolution transmission electron microscopic studies of Pt-photodeposited Ag/TiO2 demonstrate that the Ag nanoparticles act as reduction sites in the photocatalytic reaction. Both spectroscopic measurements and density functional theory (DFT) calculations reveal that nitrobenzene is selectively adsorbed onto the Ag surfaces of Ag/TiO2 via partial electron transfer from Ag to nitrobenzene, whereas the interaction between aniline and Ag/TiO2 is weak. The kinetic analysis indicates that the recombination between the electrons flowing into the Ag nanoparticle and the holes left in the TiO2 valence band is significantly suppressed, particularly in the presence of CH3OH. The high activity and selectivity in the present Ag/TiO2-photocatalyzed reduction are rationalized in terms of the charge separation efficiency, the selective adsorption of the reactants on the catalyst surfaces, and the restriction of the product readsorption.

show abstract

“…The highest photocurrent response obtained in the presence of citric acid was probably due to a rapid hole transfer to citric acid molecules. According to the reports [33,34] on zinc oxide and…”

Section: Iron Ores and Iron Oxide Materialsmentioning

confidence: 99%

Photoelectrochemistry of Hematite

Maeda¹

2018

Iron Ores and Iron Oxide Materials

View full text Add to dashboard Cite

It was possible to prepare a hematite film by electrochemical deposition of iron oxide in aqueous solution and its heat treatment at 500 C or higher temperature in air. The deposition process of iron oxide film from current and potential pulse methods was mentioned in relation to the equilibrium potential for iron oxide. The hematite in aqueous solution showed a clear photoanodic current due to visible light irradiation. The photo-oxidation response of hematite electrode to organic and inorganic materials in aqueous solution was summarized through the examples of citric acid, Pb 2+ and aniline.

show abstract

Chemical reactions of electrons and holes at the ZnO/electrolyte-solution interface

Cited by 52 publications

References 4 publications

Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

Kinetic and DFT Studies on the Ag/TiO₂‐Photocatalyzed Selective Reduction of Nitrobenzene to Aniline

Photoelectrochemistry of Hematite

Contact Info

Product

Resources

About

Chemical reactions of electrons and holes at the ZnO/electrolyte-solution interface

Cited by 52 publications

References 4 publications

Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

Kinetic and DFT Studies on the Ag/TiO2‐Photocatalyzed Selective Reduction of Nitrobenzene to Aniline

Photoelectrochemistry of Hematite

Contact Info

Product

Resources

About

Kinetic and DFT Studies on the Ag/TiO₂‐Photocatalyzed Selective Reduction of Nitrobenzene to Aniline