M. Morozova

The influence of various deposition techniques on the photoelectrochemical properties of the titanium dioxide thin film

Thin sol–gel TiO2 layers deposited on the conductive ITO glass by means of three various deposition techniques (dip-coating, inkjet printing and spray-coating) were used as photoanode in the three-compartment electrochemical cell. The thin TiO2 films were treated at 450 °C and after calcination all samples possessed the crystallographic form of anatase. The relationship between surface structure and photo-induced conductivity of the nanostructured layers was investigated. It was found that the used deposition method significantly influenced the structural properties of prepared layers; mainly, the formation of defects and their quantity in the prepared films. The surface properties of the calcined layers were determined by XRD, Raman spectroscopy, SEM, AFM, UV–Vis analyses and by the optical microscopy. The photo-induced properties of nanoparticulate TiO2/ITO photoanode were studied by electrochemical measurements combined with UV irradiation.

Ultrathin functional films of titanium(IV) oxide

Chemistry and physics of thin semiconducting layers of various types are subjects of intense research. Especially when nanotechnology methods such as self-assembly are involved, amazing structural and/or functional properties may appear. Also modern physical methods using variously organized plasma arrangements are able to produce uniform structures with distinctive functionality. In this review, based virtually on our own work, discussions on the preparation, structure, morphology, and function of titanium(IV) oxide nanoscopic thin films are presented. It was shown that structurally and functionally similar titanium(IV) oxide films can be prepared via completely different preparation techniques. Function tests were arranged as “primary”, covering the assessment of the light induced charge separation efficiency, and “secondary”, based on photocatalytic surface oxidations.

Photocatalytic water treatment on TiO2 thin layers

AbstractPhotocatalysis is generally applied as a suitable technique for water decontamination and/or purification, especially for decomposition of endocrine disruptors. Endocrine disruptors are commonly present not only in wastewater but also in natural water. Endocrine disruptors are persistent to degradation by common chemicals as well as biological and photolytic processes. Decomposition of three representative endocrine disruptors (17-ethynyl estradiol, bisphenol A, and 4-nonylphenol) was tested on previously prepared TiO2 photocatalyst in two types of reactors; a batch reactor and a plug-flow reactor. TiO2 thin layers deposited on three various substrates were prepared by a sol–gel process with employment of a dip-coating technique for subsequent application. Properties of the prepared layers were thoroughly characterized by XRD, SEM, AFM, UV–vis, and Raman spectroscopy. Photo-electrochemical properties were determined by linear voltammetry and amperometry to obtain photoinduced properties of the pre...

The influence of rutile particles on photo-induced activity of the sol–gel TiO2/ITO photo-anode

The rutile effect on structural and photo-electrochemical properties and photo-induced activity were studied. Thin TiO2 layers were prepared by the sol–gel method using a reverse micelles system as a molecular template and deposited on the conductive ITO substrate by a dip-coating technique. Pure anatase or mixed anatase/rutile phase were obtained during the calcination step as a result of the selected temperature. The crystallographic structure was determined by Raman spectroscopy and XRD analysis. The positive influence of the presence of rutile particles in the thin layer on the photo-induced properties was verified. It was found that the mixed crystallographic phase of anatase and rutile can exhibit much higher photo-induced activity than pure anatase or the pure rutile form. The reason for this is that the excited electrons can easily transfer from the anatase surface states to rutile as well as from the anatase conduction band to rutile, which improves the electron-transfer rate. The electron transport between connected anatase and rutile particles can support the photo-excited charge separation and thus reduce the recombination rate.