Synthesis, characterization and applications of nanomaterials in the field of photocatalysis

Doctoral Thesis / Dissertation from the year 2011 in the subject Chemistry - Materials Chemistry, East China University of Science and Technology (-), language: English, abstract: Considerable effort has been made to design, fabricate, and manipulate nanostructured
materials by innovative approaches. The precise control of nanoscale structures will pave the
way not only for elucidating unique size/shape dependent physicochemical properties but also
for realizing new applications in science and technology. Nanotechnology offers
unprecedented opportunities for improving our daily lives and the environment in which we
live.
This thesis mainly describes recent progress in the design, fabrication, and modification
of nanostructured semiconductor materials for environmental applications. The scope of this
thesis covers TiO2, Bi2O3 and BiOCl materials, focusing particularly on TiO2-based
nanostructures (e.g., pure, doped, coupled, mesoporous, hierarchically porous, and ordered
mesoporous TiO2).
Mesoporous titania is of particular interest since this class of materials possesses
well-defined porosity and large specific surface areas. For photocatalytic degradation of
organics, these desirable properties are anticipated to improve the efficiency. So in the first
part of work, I have synthesized the mesoporous titania by using poly ethylene glycol as a
template in dilute acetic acid aqueous solution by hydrothermal process and investigated the
effect of PEG molecular weights and thermal treatment on the resultant structure and
photocatalytic activity. When the molecular weights of PEG vary from 600 to 20,000, the
particle sizes of mesoporous-TiO2 structure decrease from 15.1 to 13.3 nm and mean pore
sizes increase from 6.9-10.6 nm. The activities of these mesoporous-TiO2 photocatalysts
prepared by using PEG are evaluated and compared with Degussa P-25 using chloro-phenol
as a testing compound. [...]