ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 9, pp. 1536−1543. © Pleiades Publishing, Ltd., 2016.
The text was submitted by the authors in English.
Degradation of pollutants in the presence of a photo-
catalyst (e.g., semiconductor metal oxides) has sparked a
great interest in the scientiﬁ c community recently. It has
been proposed that semiconductor metal oxide nanopar-
ticles have unique characteristics including catalytic,
mechanical, thermal, electronic, magnetic, and optical
properties . In addition, they have the potential to
be used in photo-electronic and gas-sensor devices .
Titanium dioxide (TiO
) and zinc oxide (ZnO) are the most
commonly used semiconducting metal oxides as they are
highly stable and exhibit effective catalytic properties .
The use of such metal oxides and in particular TiO
photocatalysts can be very useful at solving numerous en-
vironmental problems. For example, they can be used in air
and water puriﬁ cation systems  as they have the ability
to trap and photocatalyze undesirable organic materials in-
cluding acids, aldehydes, alcohols, amines, and herbicides.
Therefore, carrying out these puriﬁ cation processes could
help reduce or even eliminate the hazards associated with
the presence of undesirable organic compounds in water
and/or air systems . This is achieved as they are con-
verted to carbon dioxide, water, and simple organics [7–9].
Due to the electronic structure of semiconductors, they
become valuable scientiﬁ c tools to allow the investigation
of photochemical reactions. They are particularly useful
in light induced redox reactions which can be portrayed
by empty conduction bands and ﬁ lled valence bands. The
energy difference between these two bands is referred to
as a band gap (i.e., threshold energy).
Semiconductor photocatalysts can absorb impacting
photons that have energies equal to or higher than its
Photocatalytic Degradation of Polyhydroxybutyrate
Films Using Titanium Dioxide Nanoparticles
as a Photocatalyst
, Gamal A. El-Hiti
*, Ahmed Ahmed
, Nadia Altaee
and Emad Yousif
Department of Chemistry, College of Science, Misan University, Misan 62001, Iraq
Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University,
P.O. Box 10219, Riyadh 11433, Saudi Arabia
Polymer Research Unit, College of Science, Al-Mustansiriyah University, Bagdad, Iraq
Department of Horticulture and Garden Engineering, College of Agriculture,
Al-Qasim Green University, 51002 Babil, Iraq
Department of Chemistry, College of Science, Al-Nahrain University, Baghdad 64021, Iraq
Received July 16, 2016
Abstract—Photocatalytic degradation of polyhydroxybutyrate (PHB) polymeric ﬁ lms (30 m thickness) contain-
ing different concentrations of titanium dioxide (TiO
) nanoparticles under ultraviolet (UV) irradiation (
313 nm) has been studied. The activity of TiO
(0.0010.005%) as a photocatalyst was determined by monitoring
various functional group indices, weight loss in polymeric ﬁ lms and photodegradation rate constant (k
irradiation time. Photodegradation was found to be highly dependent on the TiO
tion and the UV irradiation time. The rate of PHB sample photodegradation was highest when the concentration
was 0.005% (by weight) and lowest when its concentration was 0.001%.