Designing Novel Photocatalysts for Disinfection of Multidrug-Resistant …
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materials found in the literature are metal oxides such as TiO 2 , ZnO, and CeO 2 .
When compared with other metal oxides, titanium dioxide (3.32 eV) is considered
better and also a hopeful candidate for the photocatalytic devastation of organic
pollutants due to its high quantum efficiency, high stability in aqueous media, and
nontoxic in nature (Konstantinou and Albanis 2004; Nakata and Fujishima 2012;
Schneider et al. 2014). ZnO and CeO 2 which have a similar bandgap of about 3.32 eV
are sometimes preferred over TiO 2 for the degradation of organic pollutants due
to its high adsorption properties (Choi et al. 2016; Saravanan et al. 2017; Zhang
et al. 2009). Unfortunately, both TiO 2 and ZnO which are highly evaluated for UV
photocatalysis are inactive under visible light due to their wide bandgaps. Resulting
their inapplicability in spite of a readily available source of visible light (almost 46%)
in the form of solar irradiation. Thus, designing the catalyst with lower bandgap is the
need of this era, requiring high throughput engineering skills and mineral and oxide
processing knowledge for achieving higher catalytic efficiency with these materials,
particularly under visible light.
Technical challenges in photocatalyst also persist while modifying them for visible light activation. When a light absorber is hybridized or merged with an additional semiconductor/cocatalyst/or mineral/metal oxide, some of the naturally existing active sites on the light absorber would be blocked by the hybrid components
due the coverage of the hybrid materials being extreme. For example, Zhang et al.
(2015) customized Ag/BiVO 4 with 4 wt% of Ag loading to find a diminished photocatalytic activity than the one with lower Ag loading. Another technical challenge
of hybridized photocatalyst is reduced light absorption due to the hybrid material
shielding phenomenon. This is mainly observed in materials like carbon nanotubes
(Ong et al. 2013) graphene, (Ong et al. 2015) and NiSx, (Yin et al. 2014). Thus, engineering them with skills is mostly entertained. Recently, the development of optically
transparent guest materials like Co(OH) 2 /Co 3 O 4 ,[86g] NiO x , (Morales-Guio et al.
2015) and NiFeO x with the expectation to reduce undesired light shielding. These
materials have proven their worth to be used in photocatalysis. Hybrid materials
also possess risk of faster electron–hole recombination for a wide variety of causes
owing to structural defects and energetic. Wu et al. (2017) reported that photoactive
octahedral Cu 2 O became inactive after adding ZnO due to unfavorable band alignment at the interface between ZnO (101) and Cu 2 O (111). Thus, the hybrid material
engineering has to be judiciously done to abate misalliances that might led to the
creation of charge traps for momentous recombination (Morales-Guio et al. 2015).
Geographical conditions of a place along with its latitude and longitude coordinates are one of the major challenges faced with photocatalysis technology. Since
the availability of sunlight is utmost near the equatorial region with good amount of
the sunlight flux in the countries locating between tropic of cancer and capricorn.
Photocatalysis has been widely used in many parts of the world with a savior role in
pathogen infested geographical locations of Asia, Africa, and South America. But its
applications are limited in Scandinavian countries where rays of sunlight are inadequate. Though the technology could be implemented with artificial light sources, but
problems associated with process economy will be the biggest of questions arising.
465
materials found in the literature are metal oxides such as TiO 2 , ZnO, and CeO 2 .
When compared with other metal oxides, titanium dioxide (3.32 eV) is considered
better and also a hopeful candidate for the photocatalytic devastation of organic
pollutants due to its high quantum efficiency, high stability in aqueous media, and
nontoxic in nature (Konstantinou and Albanis 2004; Nakata and Fujishima 2012;
Schneider et al. 2014). ZnO and CeO 2 which have a similar bandgap of about 3.32 eV
are sometimes preferred over TiO 2 for the degradation of organic pollutants due
to its high adsorption properties (Choi et al. 2016; Saravanan et al. 2017; Zhang
et al. 2009). Unfortunately, both TiO 2 and ZnO which are highly evaluated for UV
photocatalysis are inactive under visible light due to their wide bandgaps. Resulting
their inapplicability in spite of a readily available source of visible light (almost 46%)
in the form of solar irradiation. Thus, designing the catalyst with lower bandgap is the
need of this era, requiring high throughput engineering skills and mineral and oxide
processing knowledge for achieving higher catalytic efficiency with these materials,
particularly under visible light.
Technical challenges in photocatalyst also persist while modifying them for visible light activation. When a light absorber is hybridized or merged with an additional semiconductor/cocatalyst/or mineral/metal oxide, some of the naturally existing active sites on the light absorber would be blocked by the hybrid components
due the coverage of the hybrid materials being extreme. For example, Zhang et al.
(2015) customized Ag/BiVO 4 with 4 wt% of Ag loading to find a diminished photocatalytic activity than the one with lower Ag loading. Another technical challenge
of hybridized photocatalyst is reduced light absorption due to the hybrid material
shielding phenomenon. This is mainly observed in materials like carbon nanotubes
(Ong et al. 2013) graphene, (Ong et al. 2015) and NiSx, (Yin et al. 2014). Thus, engineering them with skills is mostly entertained. Recently, the development of optically
transparent guest materials like Co(OH) 2 /Co 3 O 4 ,[86g] NiO x , (Morales-Guio et al.
2015) and NiFeO x with the expectation to reduce undesired light shielding. These
materials have proven their worth to be used in photocatalysis. Hybrid materials
also possess risk of faster electron–hole recombination for a wide variety of causes
owing to structural defects and energetic. Wu et al. (2017) reported that photoactive
octahedral Cu 2 O became inactive after adding ZnO due to unfavorable band alignment at the interface between ZnO (101) and Cu 2 O (111). Thus, the hybrid material
engineering has to be judiciously done to abate misalliances that might led to the
creation of charge traps for momentous recombination (Morales-Guio et al. 2015).
Geographical conditions of a place along with its latitude and longitude coordinates are one of the major challenges faced with photocatalysis technology. Since
the availability of sunlight is utmost near the equatorial region with good amount of
the sunlight flux in the countries locating between tropic of cancer and capricorn.
Photocatalysis has been widely used in many parts of the world with a savior role in
pathogen infested geographical locations of Asia, Africa, and South America. But its
applications are limited in Scandinavian countries where rays of sunlight are inadequate. Though the technology could be implemented with artificial light sources, but
problems associated with process economy will be the biggest of questions arising.