friendly nature, and expanded solar light absorption, promoting its usage as water
pollutant eliminator. The expanded utilization of n-type semiconductor has proven to
be in component due to drawbacks like large band gap, insufficient surface area, and
rapid recombination of charge carriers. To overcome these limitations, we have
presented in detail the potential abilities of metal oxides, ferrous oxide (Fe 2 O 3 ), and
cuprous oxide (Cu 2 O) in heterojunction with g-C 3 N 4 . A fruitful discussion on
photocatalytic properties, green synthetic routes, and sustainability of g-C 3 N 4 -
Fe 2 O 3 and g-C 3 N 4 -Cu 2 O heterostructure in the arena of water restoration and
microbial disinfection is provided in this chapter.
Keywords g-C 3 N 4 · Fe 2 O 3 · Cu 2 O · Photocatalysis · Heterojunction · Wastewater
restoration · Bacterial disinfection
2.1 Introduction
The flourishing global population, expanding industrialization, and climate variations have led to pervasive depletion of already scarce resources. Environmental
pollution and excessive utilization of renewable resources have posed a major
challenge to scientific communities in the twenty-first century. The accelerating
energy demands have been so pressing that it is indispensable to scrutinize highly
efficient solar energy-driven technologies for environment restoration. The need for
solar-inspired research primarily focusses as an alternative cost-effective energy
resource in maintaining the standards of human life (Priya et al. 2016a, b; Gautam
et al. 2016a, b, c; Kumar et al. 2019). Among the multifarious energy crises, water
body deterioration has emerged at the forefront, as there is currently no scalable
provision means of conserving it (Raizada et al. 2017a, b; Singh et al. 2017). Rapid
discharge of inorganic pesticides, fertilizers, pollutants, and antibiotics decreases
biochemical oxygen demand, lessening the survival of aquatic ecosystem (Singh
et al. 2018; Gautam et al. 2016a, b, c). The increased public concerns regarding the
rising levels of these pollutants have impelled the necessity to develop an innovative
water remediation technique.
Various water treatment processes have been developed over the years but have
limited large-scale application. These are as follows: (i) Adsorption on activated
carbon and air stripping are chemically driven. (ii) Incineration leads to the formation of dioxins and furans due to incomplete combustion of organic pollutants. (iii)
Filtration, membrane-assisted, and sedimentation methods result in the formation of
heavy sludge and secondary pollutants. (iv) Biological treatment and coagulation
accumulate pollutants, with formation of non-toxic secondary pollutants (Sudhaik
et al. 2018a, b; Hasija et al. 2019a, b). Currently, the key drivers to eliminate the
limitations of conventional methods are advanced oxidation technologies for effective removal of high load of pollutants (Pare et al. 2008; Hasija et al. 2019a, b). The
mechanism of advanced oxidation technologies involves an interaction of photons
54
P. Raizada et al.
pollutant eliminator. The expanded utilization of n-type semiconductor has proven to
be in component due to drawbacks like large band gap, insufficient surface area, and
rapid recombination of charge carriers. To overcome these limitations, we have
presented in detail the potential abilities of metal oxides, ferrous oxide (Fe 2 O 3 ), and
cuprous oxide (Cu 2 O) in heterojunction with g-C 3 N 4 . A fruitful discussion on
photocatalytic properties, green synthetic routes, and sustainability of g-C 3 N 4 -
Fe 2 O 3 and g-C 3 N 4 -Cu 2 O heterostructure in the arena of water restoration and
microbial disinfection is provided in this chapter.
Keywords g-C 3 N 4 · Fe 2 O 3 · Cu 2 O · Photocatalysis · Heterojunction · Wastewater
restoration · Bacterial disinfection
2.1 Introduction
The flourishing global population, expanding industrialization, and climate variations have led to pervasive depletion of already scarce resources. Environmental
pollution and excessive utilization of renewable resources have posed a major
challenge to scientific communities in the twenty-first century. The accelerating
energy demands have been so pressing that it is indispensable to scrutinize highly
efficient solar energy-driven technologies for environment restoration. The need for
solar-inspired research primarily focusses as an alternative cost-effective energy
resource in maintaining the standards of human life (Priya et al. 2016a, b; Gautam
et al. 2016a, b, c; Kumar et al. 2019). Among the multifarious energy crises, water
body deterioration has emerged at the forefront, as there is currently no scalable
provision means of conserving it (Raizada et al. 2017a, b; Singh et al. 2017). Rapid
discharge of inorganic pesticides, fertilizers, pollutants, and antibiotics decreases
biochemical oxygen demand, lessening the survival of aquatic ecosystem (Singh
et al. 2018; Gautam et al. 2016a, b, c). The increased public concerns regarding the
rising levels of these pollutants have impelled the necessity to develop an innovative
water remediation technique.
Various water treatment processes have been developed over the years but have
limited large-scale application. These are as follows: (i) Adsorption on activated
carbon and air stripping are chemically driven. (ii) Incineration leads to the formation of dioxins and furans due to incomplete combustion of organic pollutants. (iii)
Filtration, membrane-assisted, and sedimentation methods result in the formation of
heavy sludge and secondary pollutants. (iv) Biological treatment and coagulation
accumulate pollutants, with formation of non-toxic secondary pollutants (Sudhaik
et al. 2018a, b; Hasija et al. 2019a, b). Currently, the key drivers to eliminate the
limitations of conventional methods are advanced oxidation technologies for effective removal of high load of pollutants (Pare et al. 2008; Hasija et al. 2019a, b). The
mechanism of advanced oxidation technologies involves an interaction of photons
54
P. Raizada et al.