The primary step in the thermal decomposition of acidic aqueous ozone solutions is the dissociation reaction: 03 ü O + 02. This reaction is supported by the retarding effect of 02 on the decomposition rate, by our activation energy measurements, EA = 79.5 ± 8.0 kJ moT* 1, and by isotopic exchange experiments with 18,1802. The rates of ozone decomposition were measured at pHs 0-4, at temperatures 0-46 °C, and at 02 concentrations 10"5-10~3 M. The O atom formed in the dissociation reaction is postulated to be the precursor for OH and H02 formation. The ionization of the H02 free radical (pK = 4.8) accounts for the increase in rate with rising pH. The mechanistic implications of 03 decomposition in acid solution are briefly discussed.

CdS was prepared by adding hydrogen sulfide to a solution containing about KT1 234 M Cd(C104)2 and various long-chain alkanethiols in tetrahydrofuran. With increasing thiol concentration smaller CdS particles were formed. Their absorption and fluorescence spectra were blue-shifted with decreasing particle size. The mean diameter, d (nm), of the particles depended on the thiol concentration, c (M), according to the relation log d = 1.32-0.13 log c. The colloids have remarkable stability: reflux heating (60 °C) and removal of the solvent and excess thiol (90 °C) did not affect them substantially. The separated particles could be redissolved to a large extent in organic solvents, such as cyclohexane, benzene, carbon tetrachloride, chloroform, and dichloromethane. Photolysis in the presence of oxygen led to smaller particles and finally to dissolution of the colloid. In the absence of oxygen larger particles were formed. In both cases the disulfide from the thiol used was produced, although the latter did not absorb at the wavelengths of the photolyzing light. A mechanism for these photolysis effects is discussed.

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A new highly structured system based on TiO 2 /In(OH) x S y /PbS/PEDOT:PSS/Au has been developed for photovoltaic applications. In this device, TiO 2 , In(OH) x S y , PbS and PEDOT:PSS serve as electron conductor, buffer layer, absorber and hole conductor, respectively. Both buffer and absorber layers have been prepared by chemical bath deposition. For annealed In(OH) x S y , an optical band gap of 2.2 eV has been obtained and for PbS the bulk value is widened to about 0.85 eV due to the presence of oxide in the film composition. At present stage, solar cells with such configuration have reached up to about 1% efficiency with J sc = 8 mA/cm 2 and V oc = 0.3 V.