Cleavage of Water by Visible‐Light Irradiation of Colloidal CdS Solutions; Inhibition of Photocorrosion by RuO₂

Abstract

The conversion of light into chemical fuels in photochemical devices equipped with semiconductor electrodes (e.g. of n‐CdS) is associated with a serious problem: “holes” produced in the valence band of the semidonductor upon irradiation migrate to the surface where photocorrosion occurs. In mi‐croheterogenous CdS systems this is remedied by a thin layer of RuO2. A CdS sol prepared in the presence of maleic anhydride/styrene copolymer has now been loaded with RuO2 and Pt; these CdS microelectrodes are surprisingly active catalysts for cleavage of H2O and H2S.

The effects of pH and adsorbed hydrolysed metal ions on the photodissolution of colloidal cadmium sulphide

“…The final pH was adjusted as required for subsequent experiments. The absorption spectra of the sols made in this fashion matched those reported by others [6,7].…”

“…In the presence of O2 the following mechanism may be proposed to explain the photodegradation of a metal sulphide (MS) (5) (6) (7) (8) (9) …”

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

“…The enolate ligand nucleophilically attacks a second acetone molecule to form a C À C bond (12), and the aldolate ligand is coordinated to the Ti center (13). This titanium diacetone alcoholate complex can either react to give a TiÀOH species under release of mesityl oxide and further proceed to the formation of a Ti-O-Ti bond (14), or undergo further condensation reaction with a third acetone molecule. [209] In the latter process, complex 15 is transformed into the tridentate ligand 16, which is an excellent stabilizing agent.…”

“…All electronic properties in semiconducting crystallites. [8][9][10][11][12] Intensive work on semiconductor-doped glasses [13] and on the photocatalytic properties of colloidal CdS [14,15] finally resulted in the description of the quantum-size effect more than 20 years ago. Brus et al found that CdS crystallites in the size range of a few nanometers did not have the electronic spectra of the bulk material, even though they exhibited the same unit cell and bond length as the bulk material.…”

Effect of calcination on the photocatalytic performance of CdS under visible light irradiation

“…Among these photocatalysts, hexagonal CdS as one of the most important II-VI group semiconductors has received much more attention in utilizing solar energy due to its band gap (2.4 eV) matching well with the solar spectrum [12][13][14][15][16]. For improving the photocatalytic activity of CdS, the processes in the photocatalytic reaction, including the generation, separation, recombination and migration of the photogenerated electrons and holes, should be comprehensively investigated [17,18].…”