organic pollutants as well as a high disinfection activity. This activity was attributed
to the higher light adsorption (Bai et al. 2013; Hamadanian et al. 2010).
Sanchez et al. (2014) also reported that nanorods could be prepared from the
calcination of ZnO at 350
C using spray pyrolysis solution in a water–ethanol
mixture grown on substrate fluorine-doped tin oxide. These nanorods showed
different disinfection mechanisms toward E. coli cells. The structure of the nanorods
of ZnO changed by modifying the ratio of the ethanol–water mixture, which controls
the evaporation of the solvent due to the fall in imposing the substrate under
ultraviolet and visible light irradiation. The same results were also reported by
other researchers (Alarcón et al. 2011; Sanchez et al. 2014, 2015). The ZnO and
TiO 2 nanorods showed similar bacterial disinfection under visible light (Basnet et al.
2013). Recently, Bi-based nanorods were prepared using monoclinic bismuth
tetraoxide (m-Bi 2 O 4 ) by hydrothermal process. These nanorods showed high bacterial disinfection as well as fast disintegration of organic pollutants under visible light
irradiation than CdS and Bi 2 O 3 . This finding encouraged many studies on Bi 2 O 4
nanorods under visible light irradiation. Bi 2 O 4 nanorods were reported to be highly
active and non-toxic and show stable photocatalytic performance (Wang et al.
2015a).
Nanowires
Nanowires are another one-dimensional nanomaterial type with a diameter of
20–100 nm which displays high-performance photocatalytic activity for water
disinfection. For instance, Zhang et al. (2008) reported that organic contaminants,
such as foulants, were effectively removed under ultraviolet radiation. Titanium
nanowires prepared by hydrothermal synthesis–filtration method showed high antifouling property (Zhang et al. 2008). The use of these photoactive materials and their
performance opens the opportunity for their application in the water disinfection
process. Liu et al. (2016) fabricated iron oxide nanowires (Bac-FeO x NWs) produced
by bacteria (Mariprofundus ferrooxydans) as photocatalytic material which displays
photocatalytic disinfection properties (Wang et al. 2016). These nanowires displayed
excellent reusability with no significant loss of activity even after six cycles. These
nanowires are naturally produced, inexpensive, highly active, stable, and magnetic
and have the potential to be used for broad applications including water disinfection.
Recently, efforts have been made on combining TiO 2 nanowire/nanofiber membrane with other materials such as Ag to form Ag/TiO 2 nanofiber membrane as
photocatalytic material for bacterial disinfection (Chong et al. 2010; Janpetch et al.
2015; Jin et al. 2007; Liu et al. 2012b). This combination has been shown to render
active surface sites exposed to bacteria and organic pollutants as well as the loading
of Ag nanoparticles facilitated the photogenerated e
À /h
+ separation concomitant
with the inherent antibacterial properties of Ag nanoparticles, making the combination as an excellent photocatalyst material for water disinfection. Similar to nanowire
photocatalyst, nanobelts have been reported to exhibit bacterial inactivation activity.
However, the high exposed surface area in the nanobelt crystals makes these
7 Photocatalytic Nanomaterials for Bacterial Disinfection
221
to the higher light adsorption (Bai et al. 2013; Hamadanian et al. 2010).
Sanchez et al. (2014) also reported that nanorods could be prepared from the
calcination of ZnO at 350
C using spray pyrolysis solution in a water–ethanol
mixture grown on substrate fluorine-doped tin oxide. These nanorods showed
different disinfection mechanisms toward E. coli cells. The structure of the nanorods
of ZnO changed by modifying the ratio of the ethanol–water mixture, which controls
the evaporation of the solvent due to the fall in imposing the substrate under
ultraviolet and visible light irradiation. The same results were also reported by
other researchers (Alarcón et al. 2011; Sanchez et al. 2014, 2015). The ZnO and
TiO 2 nanorods showed similar bacterial disinfection under visible light (Basnet et al.
2013). Recently, Bi-based nanorods were prepared using monoclinic bismuth
tetraoxide (m-Bi 2 O 4 ) by hydrothermal process. These nanorods showed high bacterial disinfection as well as fast disintegration of organic pollutants under visible light
irradiation than CdS and Bi 2 O 3 . This finding encouraged many studies on Bi 2 O 4
nanorods under visible light irradiation. Bi 2 O 4 nanorods were reported to be highly
active and non-toxic and show stable photocatalytic performance (Wang et al.
2015a).
Nanowires
Nanowires are another one-dimensional nanomaterial type with a diameter of
20–100 nm which displays high-performance photocatalytic activity for water
disinfection. For instance, Zhang et al. (2008) reported that organic contaminants,
such as foulants, were effectively removed under ultraviolet radiation. Titanium
nanowires prepared by hydrothermal synthesis–filtration method showed high antifouling property (Zhang et al. 2008). The use of these photoactive materials and their
performance opens the opportunity for their application in the water disinfection
process. Liu et al. (2016) fabricated iron oxide nanowires (Bac-FeO x NWs) produced
by bacteria (Mariprofundus ferrooxydans) as photocatalytic material which displays
photocatalytic disinfection properties (Wang et al. 2016). These nanowires displayed
excellent reusability with no significant loss of activity even after six cycles. These
nanowires are naturally produced, inexpensive, highly active, stable, and magnetic
and have the potential to be used for broad applications including water disinfection.
Recently, efforts have been made on combining TiO 2 nanowire/nanofiber membrane with other materials such as Ag to form Ag/TiO 2 nanofiber membrane as
photocatalytic material for bacterial disinfection (Chong et al. 2010; Janpetch et al.
2015; Jin et al. 2007; Liu et al. 2012b). This combination has been shown to render
active surface sites exposed to bacteria and organic pollutants as well as the loading
of Ag nanoparticles facilitated the photogenerated e
À /h
+ separation concomitant
with the inherent antibacterial properties of Ag nanoparticles, making the combination as an excellent photocatalyst material for water disinfection. Similar to nanowire
photocatalyst, nanobelts have been reported to exhibit bacterial inactivation activity.
However, the high exposed surface area in the nanobelt crystals makes these
7 Photocatalytic Nanomaterials for Bacterial Disinfection
221