harvest, turn, and supply clean and renewable sunlight energy. It can be performed
through entire water splitting and CO production to provide green-sustainable solar
fuels alongside of wide ranges of environmental aspects. We reviewed in the
presented chapter focusing on the application of effective nanomaterials in environmental remediation about industrial and agricultural effluents. For years TiO 2
photocatalyst has been largely utilized but includes restricted activity just in UV
spectrum due to wide band gap. Therefore, it is crucial to development of new
effective visible light-sensitive photocatalysts with lower band gap that can be
activated by a notable percentage of the solar irradiations. Herein, we try to discuss
the basic science drives for performance improving of visible/solar light
photocatalysts. First, the corresponding principles which include of thermodynamics, kinetics, and recombination rate are followed. The second section reviews the
new effective reported visible-activated photocatalytic compounds considering with
proposed photoexcitation mechanisms and reducing the charges recombination.
Finally, the main challenges and future prospects for better handling of
photocatalytic technology were briefly discussed.
Keywords Nano-photocatalyst · Photocatalytic mechanism · UV-activated ·
Visible-activated · Semiconductor
9.1 Introduction
9.1.1 General Views of Photocatalytic Remediation
During the past centuries, increasing human energy demands have been resolved by
fossil combustion-based sources such as oil, coal, and natural gases. The used
sources caused different overproductions with known and unknown impacts on
environment. Awareness about some other mineral fuel energies like nuclear source
are insufficient from waste access and defect of technology points of view (Da Rosa
2012). However, the main adverse effects of mineral fuels on air, water, and soil can
be regarded as global warming or impact on climate. Therefore, economic and
population growing global societies have urgently asked for new, renewable, inexpensive, and easy affordable clean energy sources (Nuraje et al. 2012; Da Rosa
2012; Asmatulu 2015). The clean energy sources can be mainly achieved from
natural sunlight, tides, wind, rain, biomass, and other sources without damaging
the earth. The greatest and clean sun energy source has huge magnitude releasing
near to 105 terawatts versus world’s current energy requirement of 12 terawatts,
0.01% of total amount. Nanotechnology as ongoing technology can suggest
approaches to degrading production charges, improving efficiency, and stashing
energy, healthy environmental remediation, and so on (Asmatulu et al. 2010,
2011; Luque and Balu 2013; Nuraje et al. 2013). Obviously, industrialization have
picked up greenhouse gas emission and particulate dust pollutants, continued over
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M. Chahkandi and M. Zargazi
through entire water splitting and CO production to provide green-sustainable solar
fuels alongside of wide ranges of environmental aspects. We reviewed in the
presented chapter focusing on the application of effective nanomaterials in environmental remediation about industrial and agricultural effluents. For years TiO 2
photocatalyst has been largely utilized but includes restricted activity just in UV
spectrum due to wide band gap. Therefore, it is crucial to development of new
effective visible light-sensitive photocatalysts with lower band gap that can be
activated by a notable percentage of the solar irradiations. Herein, we try to discuss
the basic science drives for performance improving of visible/solar light
photocatalysts. First, the corresponding principles which include of thermodynamics, kinetics, and recombination rate are followed. The second section reviews the
new effective reported visible-activated photocatalytic compounds considering with
proposed photoexcitation mechanisms and reducing the charges recombination.
Finally, the main challenges and future prospects for better handling of
photocatalytic technology were briefly discussed.
Keywords Nano-photocatalyst · Photocatalytic mechanism · UV-activated ·
Visible-activated · Semiconductor
9.1 Introduction
9.1.1 General Views of Photocatalytic Remediation
During the past centuries, increasing human energy demands have been resolved by
fossil combustion-based sources such as oil, coal, and natural gases. The used
sources caused different overproductions with known and unknown impacts on
environment. Awareness about some other mineral fuel energies like nuclear source
are insufficient from waste access and defect of technology points of view (Da Rosa
2012). However, the main adverse effects of mineral fuels on air, water, and soil can
be regarded as global warming or impact on climate. Therefore, economic and
population growing global societies have urgently asked for new, renewable, inexpensive, and easy affordable clean energy sources (Nuraje et al. 2012; Da Rosa
2012; Asmatulu 2015). The clean energy sources can be mainly achieved from
natural sunlight, tides, wind, rain, biomass, and other sources without damaging
the earth. The greatest and clean sun energy source has huge magnitude releasing
near to 105 terawatts versus world’s current energy requirement of 12 terawatts,
0.01% of total amount. Nanotechnology as ongoing technology can suggest
approaches to degrading production charges, improving efficiency, and stashing
energy, healthy environmental remediation, and so on (Asmatulu et al. 2010,
2011; Luque and Balu 2013; Nuraje et al. 2013). Obviously, industrialization have
picked up greenhouse gas emission and particulate dust pollutants, continued over
284
M. Chahkandi and M. Zargazi