Chapter 1
Nanotechnology for Water and Wastewater
Treatment Using Graphene Semiconductor
Composite Materials
Francis Opoku, Ephraim M. Kiarii, and Penny P. Govender
Contents
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Semiconductors Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 Basic Principles and Mechanism for Photocatalytic Pollutant Removal . . . . . . . . . . 4
1.2.2 Fundamentals of Semiconductor-Based Photocatalyst Materials . . . . . . . . . . . . . . . . . 6
1.3 Factors Controlling Photocatalytic Pollutant Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4 Characterization of Nanomaterials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.1 Charge Carrier Transfer Kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4.2 Band Structure and Light Absorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4.3 Surface Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.5 Synthesis of Nanomaterials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.6 Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.6.1 History of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.6.2 Properties and Structure of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.6.3 Synthesis of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.6.4 Characterization of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.6.5 Adsorption Mechanism of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 13
1.7 Progress on Graphene and Semiconductor Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.7.1 Graphene/Semiconductor Composites as Adsorbents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.7.2 Graphene-Based Photocatalyst Materials for Water Treatment . . . . . . . . . . . . . . . . . . . 16
1.8 Principles of Graphene/Semiconductor Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.9 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Abstract Recently, contamination of water resources has become a persistent
problem to human due to advanced industrialization and rapid population growth.
The major causes of water pollution are dye effluents from textile dyeing, pharmaceuticals, and paper printing industries. Therefore, cost-effective technologies, such
as membrane filtration, adsorption, coagulation, microbial degradation, and chemical oxidation, are adopted for the removal of pollutants from water effluents.
Graphene-based materials have gained much consideration as a novel material for
F. Opoku · E. M. Kiarii · P. P. Govender (*)
Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa
e-mail: pennyg@uj.ac.za
© Springer Nature Switzerland AG 2020
N. Dasgupta et al. (eds.), Environmental Nanotechnology Volume 4, Environmental
Chemistry for a Sustainable World 32, https://doi.org/10.1007/978-3-030-26668-4_1
1
Nanotechnology for Water and Wastewater
Treatment Using Graphene Semiconductor
Composite Materials
Francis Opoku, Ephraim M. Kiarii, and Penny P. Govender
Contents
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Semiconductors Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 Basic Principles and Mechanism for Photocatalytic Pollutant Removal . . . . . . . . . . 4
1.2.2 Fundamentals of Semiconductor-Based Photocatalyst Materials . . . . . . . . . . . . . . . . . 6
1.3 Factors Controlling Photocatalytic Pollutant Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4 Characterization of Nanomaterials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.1 Charge Carrier Transfer Kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4.2 Band Structure and Light Absorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4.3 Surface Reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.5 Synthesis of Nanomaterials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.6 Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.6.1 History of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.6.2 Properties and Structure of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.6.3 Synthesis of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.6.4 Characterization of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.6.5 Adsorption Mechanism of Graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 13
1.7 Progress on Graphene and Semiconductor Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.7.1 Graphene/Semiconductor Composites as Adsorbents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.7.2 Graphene-Based Photocatalyst Materials for Water Treatment . . . . . . . . . . . . . . . . . . . 16
1.8 Principles of Graphene/Semiconductor Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.9 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Abstract Recently, contamination of water resources has become a persistent
problem to human due to advanced industrialization and rapid population growth.
The major causes of water pollution are dye effluents from textile dyeing, pharmaceuticals, and paper printing industries. Therefore, cost-effective technologies, such
as membrane filtration, adsorption, coagulation, microbial degradation, and chemical oxidation, are adopted for the removal of pollutants from water effluents.
Graphene-based materials have gained much consideration as a novel material for
F. Opoku · E. M. Kiarii · P. P. Govender (*)
Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa
e-mail: pennyg@uj.ac.za
© Springer Nature Switzerland AG 2020
N. Dasgupta et al. (eds.), Environmental Nanotechnology Volume 4, Environmental
Chemistry for a Sustainable World 32, https://doi.org/10.1007/978-3-030-26668-4_1
1