Showing papers by "Michael Grätzel published in 1986"
171 citations
TL;DR: Three different hydrogenases added to a suspension of TiO2 (anatase) powder are able to catalyze H2 evolution under band gap illumination of the semiconducting particles, and in the presence of EDTA or methanol as electron donor.
51 citations
TL;DR: In this article, the authors showed that the viologen molecules can be reduced to radical cations in situ by optical excitation of the semiconductor, which results in a dramatic increase in the rate of radical cation dimer formation, compared with the bulk solution reaction.
32 citations
TL;DR: In this paper, the photodecomposition of hydrogen sulfide by visible light (>400 nm) has been investigated in alkaline aqueous media (0.1 m Na 2 S and 1 M NaOH).
31 citations
24 citations
TL;DR: In this paper, the reduction of Fe/sup 3 +/ and Ce/sup 4 +/ at a polycrystalline n-WO/sub 3/ rotating disk electrode was studied in the dark as a function of potential, concentration of oxidized species, and rotation frequency.
Abstract: The reduction of Fe/sup 3 +/ and Ce/sup 4 +/ at a polycrystalline n-WO/sub 3/ rotating disk electrode was studied in the dark as a function of potential, concentration of oxidized species, and rotation frequency. The measured current densities are shown to fit reasonable well to a model which involves electron transfer from the bulk of the semiconductor to the surface (rate constant K/sub 1/) and from the surface to the solution (K/sub 2/) and which involves transport of the oxidized species to the electrode surface (K/sub 3/). The dependence of K/sub 1/ and K/sub 2/ on electrode potential reveals that a significant portion of the potential drop occurs over the Helmholtz layer, indicating partial Fermi level pinning.
19 citations
TL;DR: In this article, the adsorption of horse heart cytochrome c on TiO2 surfaces has been studied using semiconductor powders, and the effect of salts on the binding capacity of the particles indicates that the adsoreption is only partly due to electrostatic interactions.
10 citations
TL;DR: In this article, the micellar properties and photochemical behaviour of sodium 9-alkylphenothiazinesulphonate and sodium ω-carbozol-9-ylalkanesulphinate (where alkyl = C10H21 and C12H25) have been examined for the fundamental study of photoionization in mousellar assemblies.
Abstract: The micellar properties and photochemical behaviour of sodium 9-alkylphenothiazinesulphonate and sodium ω-carbozol-9-ylalkanesulphonate (where alkyl = C10H21 and C12H25) have been examined for the fundamental study of photoionization in micellar assemblies.
5 citations
01 Jan 1986
TL;DR: In this article, the authors present recent results concerning the nature and reactivity of charge carriers in colloidal semiconductor particles using laser photolysis technique with picosecond time resolution, and they have been able to monitor directly the dynamics of fundamental processes such as charge carrier trapping and recombination.
Abstract: In this lecture I shall present recent results concerning the nature and reactivity of charge carriers in colloidal semiconductor particles. Using laser photolysis technique with picosecond time resolution, we have been able to monitor directly the dynamics of fundamental processes such as charge carrier trapping and recombination. Furthermore, it is possible, by using flash excitation of colloidal semiconductors, to determine the rate of inter facial charge transfer from the conduction and valence band of the particle to species present at the surface or in solution. In the second part of my lecture, I shall address the question of catalytic water cleavage by UV and visible light. Of particular importance in this context is the question of visible light sensitization of wide band semiconductors such as titanium oxide. A recent discovery in our laboratory has allowed to push the quantum yields for incident monochromatic visible light to current conversion to an unprecedented high level of more than 50%. Finally, I wish to present some surprising and very promising results concerning a new homogeneous and highly active catalyst for the oxidation of water to oxygen.
3 citations
01 Jan 1986
TL;DR: Aqueous suspensions of CdS loaded with Rh2O3 have been evolved for hydrogen generation from water under illumination with visible light in the presence of TiO2 or K2PtCl4 as mentioned in this paper.
Abstract: Aqueous suspensions of CdS loaded with Rh2O3 have been evolved for hydrogen generation from water under illumination with visible light in the presence of TiO2 or K2PtCl4. The catalytic activity of Rh2O3 is superior to that of RuO2 in promoting water splitting under alkaline conditions.
1 citations