THE EFFECT OF PHOTOINDUCED SUPERHYDROPHILICITY OF METAL OXIDE SURFACES
In this review, the analysis of literature on fundamental exploration of the photoinduced superhydriphilicity phenomenon on the metal oxide surfaces has been presented as from its discovery in 1997 to nowadays. It was figured out that main difficulties in research are characterization of initial state and poor reproducibility of the results presented by different research groups. Three dominating in literature hypothesized mechanisms of the effect have been reviewed. It was concluded that there is no common and experimentally supported theory on the origin of photoinduced superhydrophility effect yet; the conclusions made by different authors contradict to each other. It was clearly shown that electronic photoexcitation of solids plays an important role at the first stages of surface photoinduced hydrophilic conversion. Also, it was shown the necessity to take into account the existence of poly-layered hydrate coverage on the surface of nanocoatings and the surface energy alteration during thermodynamic equilibrium stating under any influence, including UV irradiation. At the same time, subsequent stages of mechanism still remain elusive.