Photoelectrochemistry with the optical rotating disc electrode Part 2. Steady-state and transient studies on colloidal CdS

Boxall, Colin; Albery, W. John

doi:10.1039/b001338m

Cited by 5 publications

(3 citation statements)

References 39 publications

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“…These results can be somewhat related to the work by Albery et al on CdS and TiO 2 at optical rotating disk electrodes. [43][44][45] However, the latter approach describes the dynamics of particle-toelectrode charge transfer and the corresponding mass-transfer phenomena. A key aspect in the studies shown here is the molecular nature of the interfacial region; consequently, the dynamics of charge transfer are free from interference arising from electronic interactions with metallic surfaces.…”

Section: Photoelectrochemical Behavior Of Tiomentioning

confidence: 99%

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO₂ Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

et al. 2002

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The photoelectrochemical properties of TiO 2 anatase nanoparticles were studied at the water|1,2-dichloroethane (DCE) interface under potentiostatic control. The interfacial concentration of the electrostatically stabilized particles can be effectively tuned by the Galvani potential difference and the pH of the aqueous phase. At pH values lower than that corresponding to the point of zero zeta potential, the particles assemble at the liquid|liquid boundary region upon positive polarization with respect to the Galvani potential in the organic phase. Upon band-gap illumination, photocurrent responses are observed in the presence of ferrocene in the organic phase. The potential and wavelength dependencies of the photocurrent unambiguously reveal that the photoresponses arises from the transfer of valence-band holes to the redox couple in DCE. The hole transfer is mediated via the generation of OH s• at the particle surface. On the other hand, photocurrents of the opposite sign were observed in the presence of TCNQ at pH's higher than 10. In this pH range, the particles are negatively charged, and the formation of the interfacial assembly takes place upon negative polarization with respect to the organic phase. The effect of the pH and the Galvani potential difference on the photocurrent suggests that heterogeneous charge transfer is in effective competition with recombination via OH s• as well as oxygen evolution at the particle surface. These studies open new possibilities for contactless photoelectrochemical and spectroscopic characterization of nanoparticles in solution in the presence of an electric field.

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Section: Photoelectrochemical Behavior Of Tiomentioning

confidence: 99%

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO₂ Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

et al. 2002

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“…Metallic or metalloid semiconductors, such as AgI, TiO 2 , ZnO, and SnO 2 , and sulfide semiconductors, such as ZnS and CdS, have been synthesized as photocatalytic materials [4][5][6][7]. Due to their strong light absorption ability, abundant active sites, and suitable band gaps, CdS nanoparticles have become one of the most promising photocatalysts and have been widely studied and utilized in photocatalytic applications [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Redox-Enhanced Photoelectrochemical Activity in PHV/CdS Hybrid Film

Liu

et al. 2023

Nanomaterials

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Semiconductive photocatalytic materials have received increasing attention recently due to their ability to transform solar energy into chemical fuels and photodegrade a wide range of pollutants. Among them, cadmium sulfide (CdS) nanoparticles have been extensively studied as semiconductive photocatalysts in previous studies on hydrogen generation and environmental purification due to their suitable bandgap and sensitive light response. However, the practical applications of CdS are limited by its low charge separation, which is caused by its weak ability to separate photo-generated electron-hole pairs. In order to enhance the photoelectrochemical activity of CdS, a polymer based on viologen (PHV) was utilized to create a series of PHV/CdS hybrid films so that the viologen unit could work as the electron acceptor to increase the charge separation. In this work, various electrochemical, spectroscopic, and microscopic methods were utilized to analyze the hybrid films, and the results indicated that introducing PHV can significantly improve the performance of CdS. The photoelectrochemical activities of the hybrid films were also evaluated at various ratios, and it was discovered that a PHV-to-CdS ratio of 2:1 was the ideal ratio for the hybrid films. In comparison with CdS nanoparticles, the PHV/CdS hybrid film has a relatively lower band gap, and it can inhibit the recombination of electrons and holes, enhancing its photoelectrochemical activities. All of these merits make the PHV/CdS hybrid film as a strong candidate for photocatalysis applications in the future.

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“…This choice was dictated by the simplicity of this system. Moreover, while the kinetics of the dispersed CdS colloid/MV system has been well-studied by such methods as time-resolved spectroscopy, rotating ring disk electrode voltammetry, , and impedance spectroscopy, similar studies of PET at the CdS thin film/MV interface have not appeared.…”

Section: Introductionmentioning

confidence: 99%

Scanning Electrochemical Microscopy. 42. Studies of the Kinetics and Photoelectrochemistry of Thin Film CdS/Electrolyte Interfaces

Haram

Bard

2001

J. Phys. Chem. B

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We report here the novel use of scanning electrochemical microscopy (SECM) to study photoelectron transfer (PET) kinetics at the semiconductor/electrolyte interface. The model system chosen consisted of a polycrystalline cadmium sulfide thin film in contact with methyl viologen (MV 2+/+ ) and triethanolamine (TEOA) as redox mediator and hole scavenger, respectively. In the absence of illumination, SECM approach curves to CdS films deposited on glass showed negative feedback, consistent with an insulating substrate. Upon film illumination, positive feedback was obtained due to photoelectron reduction of MV 2+ at the interface. The dependence of the pseudo-first-order rate constants (k eff ) on light intensity and scavenger and mediator concentrations was estimated and the quantum efficiency as a function of light intensity was determined.

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Photoelectrochemistry with the optical rotating disc electrode Part 2. Steady-state and transient studies on colloidal CdS

Cited by 5 publications

References 39 publications

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO₂ Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO₂ Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

Redox-Enhanced Photoelectrochemical Activity in PHV/CdS Hybrid Film

Scanning Electrochemical Microscopy. 42. Studies of the Kinetics and Photoelectrochemistry of Thin Film CdS/Electrolyte Interfaces

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Photoelectrochemistry with the optical rotating disc electrode Part 2. Steady-state and transient studies on colloidal CdS

Cited by 5 publications

References 39 publications

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO2 Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO2 Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

Redox-Enhanced Photoelectrochemical Activity in PHV/CdS Hybrid Film

Scanning Electrochemical Microscopy. 42. Studies of the Kinetics and Photoelectrochemistry of Thin Film CdS/Electrolyte Interfaces

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Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO₂ Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions

Organization and Reactivity of Nanoparticles at Molecular Interfaces. Part I. Photoelectrochemical Responses Involving TiO₂ Nanoparticles Assembled at Polarizable Water|1,2-Dichloroethane Junctions