Showing papers by "Ch. Comninellis published in 1996"

Physicochemical Properties of SnO2 ‐ Sb2 O 5 Films Prepared by the Spray Pyrolysis Technique

Abstract: Tin dioxide films doped with Sb(V) of F{sup {minus}} have interesting electrochemical properties in different electrode processes, like low temperature electrochemical combustion of organic pollutants, ozone production, and organic electrosynthesis. The properties of SnO{sub 2}-Sb{sub 2}O{sub 5} mixed-oxide films prepared by the spray pyrolysis method were studied under different synthesis conditions. The film density, measured by profilometry and by a spectrophotometric method, was close to that reported in the literature for crystalline tin dioxide. Analysis by energy dispersive spectrometry and X-ray photoelectron spectroscopy showed that the Sb/Sn atom ratio int eh films was in all cases about 2.5 times larger with respect to that in the precursor solution. Microstructural characterization by wide-angle X-ray scattering indicates that the deposits consist of large sized crystallites. The influence of the substrate temperature (T) on the average crystallite size (l) has shown that l decreases linearly with T. Scanning electron microscopy showed that the surface of films thinner than 0.5--0.8 {micro}m is flat with only a limited number of emerging particles.

Preparation of SnO2-Sb2O5 films by the spray pyrolysis technique

Abstract: Spray pyrolysis has been widely used for the preparation of thin (∼0.1 μm) and transparent SnO2 films on glass substrates. In the present paper the parameters of the spray pyrolysis for the preparation of thick SnO2-Sb2O5 conductive films on Ti substrates have been studied for electrochemical use. It has been found that the resistivity of the films exhibits a minimum for a Sb concentration of about 3 at % (precursor solution concentration) and for a preparation temperature of 550°C. As far as the composition is concerned, it has been shown that the antimony concentration in the oxide. films is about twice as large as that in the corresponding precursor solution. The dependence of the oxide loading on the substrate temperature and nature and the influence of the spray conditions have also been discussed.

Physicochemical properties of SnO2-Sb2O5 films prepared by the spray pyrolysis technique

Abstract: The properties of SnO2-Sb2O5 mixed-oxide films prepd. by the spray pyrolysis method were studied under different synthesis conditions. The film d., measured by profilometry and by a spectrophotometric method, was close to that reported in the literature for cryst. tin dioxide. Anal. by energy dispersive spectrometry and x-ray photo-electron spectroscopy showed that the Sb/Sn atom ratio in the films was in all cases about 2.5 times larger with respect to that in the precursor soln. Microstructural characterization by wide-angle x-ray scattering indicates that the deposits consist of large sized crystallites. The influence of the substrate temp. (T) on the av. crystallite size (l) has shown that l decreases linearly with T. SEM showed that the surface of films thinner than 0.5-0.8 mm is flat with only a limited no. of emerging particles. [on SciFinder (R)]