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

Abstract

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.

Mn3O4/graphene nanocomposites: outstanding performances as highly efficient photocatalysts and microwave absorbers

“…3 However, TiO 2 limitation due to its restricted activation in near UV region as well as the high recombination of its electron-hole pair hinders its photocatalytic applications under visible irradiation. 4 Thus, great effort has been dedicated to develop unique photocatalysts, which could exhibit higher activity under visible light illumination. 5 Among them, Mnbased catalysts especially Mn 3 O 4 is known to be an effective catalyst for de-NOx reactions, raw materials for electronics and information devices.…”

TiO2 alterations with natural aging: Unveiling the role of nitric acid on NIR reflectance

“…Moreover, changes in wettability upon UV irradiation lead to a superhydrophilic state which, coupled with photocatalysis, results in the so called self-cleaning effect [15]. In such mechanism, the bridging groups used by atmospheric contaminants and soot to adhere to surfaces are partially photomineralized and subsequently washed away by water, allowing materials to retain a cleaner and more reflective surface over time [16][17][18]. In addition, reducing the impact of aging on the optical-radiative performance of built environment surfaces has a strong influence on the thermal comfort and energy consumption of buildings [19,20], and therefore on the urban microclimate [21].…”

Hierarchical nano ZnO-micro TiO2 composites: High UV protection yield lowering photodegradation in sunscreens

“…In the case of TiO 2 , left side in Fig. 8a, it is described [3,42] the formation of a hole (h + ) in the valence band because of the promotion of an electron (e -) to the conduction band when TiO 2 is irradiated. The valence band hole represents a highly localized electron vacancy in the semiconductor particle.…”

“…Introduction Photocatalytic semiconductor nanoparticles are being studied for a wide range of applications including water treatment, dye-sensitized solar cells, photoelectronic devices and selfcleaning surfaces [1,2]. TiO 2 nanoparticles, the most commonly used engineered nanomaterial, are found in numerous industrial products and applications [3]. ZnO is also widely studied for its photocatalytic ability and it is used in several commercial applications [4].…”