water pollution becomes one of the most serious global issues, especially, water
pollutions that contaminate various types of organic compounds
(Meenakshisundaram 2019), including pharmaceuticals and personal care products,
persistent organic pollutants, and organic dyes.
In recent years, many researchers have developed the remediation techniques of
organic pollutants in water. Photocatalysis, as one of the advanced oxidation processes (AOPs) using reactive oxidative radicals or species, particularly hydroxyl
radicals, to remediate the organic pollutants, has drawn much attention recently.
Various types of photocatalysis can be considered to be a green and effective
strategy for solving global environmental and energy problems. The possibility to
utilize solar energy as a free energy from nature to solve the environmental problems
is the key significance of photocatalysis. In this chapter, the basic concept of
photocatalysis, various organic pollutants in water, photocatalytic remediation of
organic pollutants in water, and modifications of heterogeneous photocatalysts are
discussed. Recent developments of photocatalytic reactors for remediation of
organic pollutants are presented briefly.
1.2 Photocatalysis
Photocatalysis is a type of catalysis which a chemical reaction is accelerated in the
presence of a catalyst (so-called photocatalyst) on exposure to light which is mostly
described in term of photon (hν) – an elementary particle of light, where the
photocatalyst participates in the chemical reaction without being consumed.
Photocatalysis can be also defined as the acceleration of a photoreaction (e.g.,
photolysis) in the presence of a catalyst.
1.2.1 Type of Photocatalysis
Photocatalysis could be classified to be two types, i.e., homogeneous and heterogeneous photocatalysis, on the basis of appearances of the physical state of reactants.
Homogenous Photocatalysis
Homogeneous photocatalysis is the process that the photocatalyst is in the same
phase (i.e., gas, solid, or liquid) with the reactant. The process of homogenous
photocatalysis is driven under exposure to light which a molecular photocatalyst is
promoted to the excited state (strong reductant and oxidant). Almost homogeneous
photocatalysts can drive full redox reactions which most researchers use in water
splitting to hydrogen and oxygen.
1 Photocatalytic Remediation of Organic Pollutants in Water
3
pollutions that contaminate various types of organic compounds
(Meenakshisundaram 2019), including pharmaceuticals and personal care products,
persistent organic pollutants, and organic dyes.
In recent years, many researchers have developed the remediation techniques of
organic pollutants in water. Photocatalysis, as one of the advanced oxidation processes (AOPs) using reactive oxidative radicals or species, particularly hydroxyl
radicals, to remediate the organic pollutants, has drawn much attention recently.
Various types of photocatalysis can be considered to be a green and effective
strategy for solving global environmental and energy problems. The possibility to
utilize solar energy as a free energy from nature to solve the environmental problems
is the key significance of photocatalysis. In this chapter, the basic concept of
photocatalysis, various organic pollutants in water, photocatalytic remediation of
organic pollutants in water, and modifications of heterogeneous photocatalysts are
discussed. Recent developments of photocatalytic reactors for remediation of
organic pollutants are presented briefly.
1.2 Photocatalysis
Photocatalysis is a type of catalysis which a chemical reaction is accelerated in the
presence of a catalyst (so-called photocatalyst) on exposure to light which is mostly
described in term of photon (hν) – an elementary particle of light, where the
photocatalyst participates in the chemical reaction without being consumed.
Photocatalysis can be also defined as the acceleration of a photoreaction (e.g.,
photolysis) in the presence of a catalyst.
1.2.1 Type of Photocatalysis
Photocatalysis could be classified to be two types, i.e., homogeneous and heterogeneous photocatalysis, on the basis of appearances of the physical state of reactants.
Homogenous Photocatalysis
Homogeneous photocatalysis is the process that the photocatalyst is in the same
phase (i.e., gas, solid, or liquid) with the reactant. The process of homogenous
photocatalysis is driven under exposure to light which a molecular photocatalyst is
promoted to the excited state (strong reductant and oxidant). Almost homogeneous
photocatalysts can drive full redox reactions which most researchers use in water
splitting to hydrogen and oxygen.
1 Photocatalytic Remediation of Organic Pollutants in Water
3