![]() ![]() The present work reviews the anatase to rutile phase transformation. The presence of either or both of these phases impacts on the photocatalytic performance of the material. The transformation is retarded in vacuum this retardation is attributed to the introduction of titanium interstitials.Ībstract: The utilization of solar irradiation to supply energy or to initiate chemical reactions is already an established idea If a wide-band gap semiconductor like titanium dioxide (TiO 2 ) is irradiated with light, excited electron–hole pairs result that can be applied in solar cells to generate electricity or in chemical processes to create or degrade specific compounds Recently, a new process used on the surface of TiO 2 films, namely, photoinduced superhydrophilicity, is described All three appearances of the photoreactivity of TiO 2 are discussed in detail in this review, but the main focus is on the photocatalytic activity towards environmentally hazardous compounds (organic, inorganic, and biological materials), which are found in wastewater or in air Besides information on the mechanistical aspects and applications of these kinds of reactions, a description of the attempts and possibilities to improve the reactivity is also provided This paper would like to assist the reader in getting an overview of this exciting, but also complicated, fieldĪbstract: Titanium dioxide, TiO2, is an important photocatalytic material that exists as two main polymorphs, anatase and rutile. CuO additions and hydrogen atmospheres accelerated the transformation by the introduction of oxygen vacancies and/or by reduction to a second TinO2n−1 Magneli phase which could act as a nucleating agent. It is suggested that, in general, oxygen vacancies accelerate and the interstitials inhibit the transformation. the concentration of oxygen vacancies or interstitials. The rate of transformation and activation energy are governed by the nature and amount of impurities which determine the defect structure of the TiO2, i.e. Analysis of these curves by several rate laws led to activation energies for nucleation of 109, 136, and 148 kcal/mole and for growth of 100, 115, and 190 kcal/mole, respectively. time, which were interpreted in terms of a nucleation-growth process. Abstract: Transformation of three commercial anatase powders resulted in sigmoid curves of transformation vs. ![]()
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