Investigation of the Effects of Controlled Periodic Illumination on the Oxidation of Gaseous Trichloroethylene Using a Thin Film of TiO2

Quantum yield enhancement in the photocatalytic HCOOH decomposition to H2 under periodic illumination

Despite numerous studies on controlled periodic illumination to improve the quantum yield of photocatalytic reactions, debates still exist on the nature of such effect. In our system, we proposed that enhanced electron transfer is the promotion mechanism.

Chances and limitations of nanosized titanium dioxide practical application in view of its physicochemical properties

Nanotechnology is a field of science that is nowadays developing in a dynamic way. It seems to offer almost endless opportunities of contribution to many areas of economy and human activity, in general. Thanks to nanotechnology, the so-called nanomaterials can be designed. They present structurally altered materials, with their physical, chemical and biological properties entirely differing from properties of the same materials manufactured in microtechnology. Nanotechnology creates a unique opportunity to modify the matter at the level of atoms and particles. Therefore, it has become possible to obtain items displaying new, useful properties, i.e. self-disinfecting and self-cleaning surfaces. Those surfaces are usually covered by a thin layer of a photocatalyst. The role of the photocatalyst is most of the time performed by the nanosized titanium dioxide (nano-TiO2). Excitation of nano-TiO2 by ultraviolet radiation initiates advanced oxidation processes and reactions leading to the creation of oxygen vacancies that bind water particles. As a result, photocatalytic surfaces are given new properties. Those properties can then be applied in a variety of disciplines, such as medicine, food hygiene, environmental protection or building industry. Practically, the applications include inactivation of microorganisms, degradation of toxins, removing pollutants from buildings and manufacturing of fog-free windows or mirrors.

Antenna Mechanism and De-Aggregation Concept: Novel Mechanistic Principles for Photocatalysis

TiO2 photocatalysis has attracted a great deal of attention during the last three decades. One major goal in this field is the design and preparation of TiO2 based photocatalysts possessing high photocatalytic activity to satisfy the requirements for practical applications. For the development of successful strategies to achieve this goal it is of utmost importance to improve the mechanistic understanding of the basic principles of photocatalysis. Therefore, various nanosized TiO2 photocatalysts including pure TiO2, Fe(III)-doped TiO2 and platinized TiO2 have been synthesized in our laboratories and their photocatalytic activity has been studied in detail. In particular, the correlation between the structural characteristics of these newly synthesized catalysts and their photocatalytic activity has been addressed. To explain the unexpected behavior of these materials novel mechanistic principles, i.e., the antenna mechanism and the so-called deaggregation concept have been developed and will be explained in this review.