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This paper is concerned with the study of metallorganic chemical vapor deposition (MOCVD) anatase film growth, with the aim of assessing the relationship between the TiO2 surface morphology and the photocatalytic properties of the films, particularly their relation to the decomposition of ethylbenzene at 50μgnormalm−3 in humidified air. We have found an interesting relationship between the structural properties of TiO2 films deposited by MOCVD at 400°C for different deposition times. We observed the maximum efficiency of films in the thickness range of 600–900 nm, while in a higher thickness, this activity relentlessly decreased. From atomic force microscopy analysis, it was ascertained that this reduction was not due to a decrease in the superficial area, which showed a constant roughness of films thicker than 600 nm. From X-ray diffraction analysis, the films always grew in the anatase TiO2 structure, but the thicker the films, the more pronounced the (100) preferred orientation. Thanks also to theoretical considerations, it was concluded that the activity decrease in the 900–1800 nm thickness range was due to the particularly strong increase in the (100) plane-oriented crystallites recorded in the same range, causing a decrease in surface energy and, contemporaneously, a hindering effect on photocatalytic activity.

On the basis of the study of the thermal behavior of [Mg(tmhd)2(TMEDA)] (1; tmhd =2,2,6,6-tetramethyl-3,5-heptanedionate; TMEDA = N,N,N′,N′-tetramethylethylenediamine), a novel procedure for magnesium oxide thin film growth has been developed for chemical vapor deposition (CVD) applications. Complementary studies (thermogravimetric measurements and IR and NMR spectroscopy) enabled revelation of the dissociation of TMEDA from 1, confirmed by the detection of both free TMEDA in the vapor phase and less volatile [Mg2(tmhd)4] (2) as a residue after sublimation. The effect of this dissociation is an unwanted changeable sublimation rate of the precursor 1 during the CVD process. The endeavor of a constant deposition rate by simultaneously exploiting the good volatility of 1 was achieved through its synthesis in situ by using 2 with a diamine enriched carrier. Laser reflectance interferometry (LRI) measurements testified that such a method ensured a good and constant deposition rate throughout the growth experiment, independently of the adopted processing conditions. In addition, X-ray diffraction (XRD) measurements revealed the obtainment of textured and polycrystalline MgO coatings on sapphire and on Si(100). The system chemical composition was investigated by X-ray photoelectron spectroscopy (XPS).

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