Chapter 4
MoS 2 Based Nanocomposites for Treatment
of Industrial Effluents
Manjot Kaur, Unni Krishnan, and Akshay Kumar
Abstract Water pollution due to various industrial pollutants is a major threat for
safe environment. Conventional methodology for removal of these pollutants is
hindered by various obstacles. However, photocatalysis has been considered by
many industries as solution for removal of these pollutants because of its advantageous features. Semiconductor transition metal dichalcogenides with unique properties are gaining lot of interest as photocatalyst. Molybdenum disulfide (MoS 2 )
from metal dichalcogenide family is promising for photocatalysis due to existence of
direct band gap but it possesses some limitations such as lack of emission, high
recombination and stacking faults. MoS 2 based nanocomposites overcome these
limitations and has a great degradation efficiency for degrading all major pollutants
and dyes.
This chapter reviews the emerging trends and various combinations of MoS 2
based nanocomposites utilised for wastewater treatment. The major pollutants are
the industrial wastes of azo and nitroaromatic based compounds. MoS 2 based
nanocomposites like SnO 2 /Ag/MoS 2 , MoS 2 /GO and MoS 2 /TiO 2 have exhibited
degradation efficiency of ~ 90% against 2,4-diclorophenol (DCP), 99% against
methylene blue and 99.35% reduction in 4-nitrophenol respectively. A comprehensive review of mechanism followed by nanocomposites for degradation is also
elucidated in this chapter. Most of their degradation mechanism followed a
Z-scheme or heterojunction formation, which showed high results. Additionally,
PANI@MoS 2 nanocomposites has good removal rate against heavy metals like Cr
(VI). This chapter also discusses various factors which effect the photocatalytic
property. Degradation efficiencies are dependent on factors like bandgap, phases and
morphology. The photocatalytic efficacy is attributed to OH⦁ and ⦁O 2
À radicals,
which affects reusability and efficiency. Finally, the chapter also provides an insight
into constraints in photocatalysis and the advantages of MoS 2 based nanocomposites
to overcome the same.
M. Kaur · U. Krishnan · A. Kumar (*)
Advanced Functional Materials Laboratory, Department of Nanotechnology, Sri Guru Granth
Sahib World University, Fatehgarh Sahib, Punjab, India
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. Rajendran et al. (eds.), Metal, Metal-Oxides and Metal-Organic Frameworks for
Environmental Remediation, Environmental Chemistry for a Sustainable World 64,
https://doi.org/10.1007/978-3-030-68976-6_4
97
MoS 2 Based Nanocomposites for Treatment
of Industrial Effluents
Manjot Kaur, Unni Krishnan, and Akshay Kumar
Abstract Water pollution due to various industrial pollutants is a major threat for
safe environment. Conventional methodology for removal of these pollutants is
hindered by various obstacles. However, photocatalysis has been considered by
many industries as solution for removal of these pollutants because of its advantageous features. Semiconductor transition metal dichalcogenides with unique properties are gaining lot of interest as photocatalyst. Molybdenum disulfide (MoS 2 )
from metal dichalcogenide family is promising for photocatalysis due to existence of
direct band gap but it possesses some limitations such as lack of emission, high
recombination and stacking faults. MoS 2 based nanocomposites overcome these
limitations and has a great degradation efficiency for degrading all major pollutants
and dyes.
This chapter reviews the emerging trends and various combinations of MoS 2
based nanocomposites utilised for wastewater treatment. The major pollutants are
the industrial wastes of azo and nitroaromatic based compounds. MoS 2 based
nanocomposites like SnO 2 /Ag/MoS 2 , MoS 2 /GO and MoS 2 /TiO 2 have exhibited
degradation efficiency of ~ 90% against 2,4-diclorophenol (DCP), 99% against
methylene blue and 99.35% reduction in 4-nitrophenol respectively. A comprehensive review of mechanism followed by nanocomposites for degradation is also
elucidated in this chapter. Most of their degradation mechanism followed a
Z-scheme or heterojunction formation, which showed high results. Additionally,
PANI@MoS 2 nanocomposites has good removal rate against heavy metals like Cr
(VI). This chapter also discusses various factors which effect the photocatalytic
property. Degradation efficiencies are dependent on factors like bandgap, phases and
morphology. The photocatalytic efficacy is attributed to OH⦁ and ⦁O 2
À radicals,
which affects reusability and efficiency. Finally, the chapter also provides an insight
into constraints in photocatalysis and the advantages of MoS 2 based nanocomposites
to overcome the same.
M. Kaur · U. Krishnan · A. Kumar (*)
Advanced Functional Materials Laboratory, Department of Nanotechnology, Sri Guru Granth
Sahib World University, Fatehgarh Sahib, Punjab, India
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. Rajendran et al. (eds.), Metal, Metal-Oxides and Metal-Organic Frameworks for
Environmental Remediation, Environmental Chemistry for a Sustainable World 64,
https://doi.org/10.1007/978-3-030-68976-6_4
97