Typical Synthesis and Environmental Application of Novel Ti Nanoparticles - Advanced Materials for Agriculture, Food and Environmental Safety - page 420

in the environment. Environmental pollution is any discharge of material
or energy into air, land or water, that causes or may cause acute immediate
or continuing detriment to the Earth's ecological balance or that lowers the
eminence of life. Pollutants may cause primary damage with direct iden-
tii able impact on the environment, or secondary damage in the form of
minor perturbations in the delicate balance of the biological food web that
are detectable only over long time periods. Factors contributing to pollu-
tion such as the industrialization of society, the introduction of motorized
vehicles, and the explosion of the human population, and an exponential
growth in the production of goods and services.
Although many dif erent types of pollution have been observed (i.e.,
water, air, noise, thermal, land, pesticide, radiation, etc.), the focus of
this chapter is water pollution. In the 21st century, water pollution is a
worldwide environmental problem typically created from industrial and
agricultural wastes. Most of the dyes produced by dyeing, painting, and
textile industries contain dif erent organic or inorganic contaminants,
which are toxic and carcinogenic; and thus they have imposed a serious
problem in the environment [1-4]. h erefore, a major focus for every
scientist is the development and implementation of ei cient, consistent
and proi table techniques for the removal of such toxic contaminants.
Among the dif erent kinds of procedures, one of the best procedures is
the photocatalytic oxidation of organic pollutants in wastewater and air,
as an advanced oxidation process has been proven to be an ef ective tech-
nique for environmental remediation. To develop ei cient photocatalytic
systems, high-quality semiconductor-based materials have been actively
studied in recent years. Among a wide spectrum of semiconductors, TiO 2
has attracted signii cant attention over the past decades due to its excel-
lent performance as a photocatalyst under UV light irradiation. h e most
commonly used TiO 2 for environmental applications is the commercial
Degussa P25 TiO 2 [5-6]. h e photocatalyst is normally 99.5% pure TiO 2
(80% anatase and 20% rutile). h e model structure of the rutile and antase
TiO 2 photocatalyst [6] is illustrated in Figure 15.1a and 15.1b.
In this context, novel TiO 2 or mesoporous compounds have an impor-
tant role in photochemical reactions for removal of such types of pollut-
ants. Novel or mesoporous titanium dioxide (TiO 2 ) has continued to be
highly active in photocatalytic applications because of its high surface area
and continuous particle framework, which may be benei cial, compared
to separate individual nanoparticles, in particular for catalyst recovery
[7-8]. In the past decade, there have been few reports about mesopo-
rous transition-metal oxides [9-11]. Doped TiO 2 with high surface area
transfers the electrons from the dye molecules to the transfer conduction