Carbon Nanomaterials and their Composites as Adsorbents

Nanomaterials have grown over the years globally associated to their advancement in the past decades and remarkable impact to the various applications. This chapter discussed the properties of the nanomaterials namely electrical, magnetic, mechanical, and antibacterial properties. Subsequently, the types of nanomaterials selected to be discussed in this book chapter are carbon, inorganic, organic, and composite based nanomaterials. The latter part of the book chapter shall focus on the classification of nanomaterials from zero dimensional to three dimensional and the synthesis of nanomaterials typically on bottom-up and top-downapproach.

Carbon is one of the highly explored materials because of its exceptional properties such as high chemical stability, superior mechanical strength, catenation property, anisotropy and conductivity. Researchers have investigated numerous morphologies of carbon, specially at the nanoscale for their utilization in the advancements of various operational areas. This chapter deals with the overview of various carbon based nanoadsorbents (CNs): Carbon nanotubes (CNTs), Graphene and its derivatives, fullerenes and carbon quantum dots (CQDs). The structure, exceptional properties and synthetic strategies of these nanoadsorbents have been discussed and compared. The shifts and advancements in these strategies were observed towards a greener perspective, so that CNs can be adopted as a suitable and efficient alternative for conventional techniques of water purification.

Carbon nanomaterials with various nanostructures (carbon nanotubes, graphene, graphene oxide, fullerene, nano diamonds, carbon quantum dots, carbon nanofibers, graphitic carbon nitrides, and nano porous carbons) are the decade’s most distinguishing and popular materials. They have distinctive physicochemical qualities such as chemical stability, mechanical strength, hardness, thermal and electrical conductivities, and so on. Furthermore, they are easily surface functionalized and tweaked, modifying them for high-end specific applications. Carbon nanostructures’ properties and surface characteristics are determined by the synthesis method used to create them. Nanoscience and nanotechnology have the potential to create materials with unexpected functions and qualities, which are transforming all industries. Carbon nanoparticles such as fullerene, carbon nanotubes, and graphene stand out among the various kinds of nanomaterials. These nanoparticles offer a wide range of practical applications, particularly in adsorption processes. Carbon nanoparticles exhibit unique structures that could be used in the construction of extremely sensitive, selective, and effective adsorbent devices for the removal of inorganic, organic, and biological pollutants from water solutions, as well as nano sensors and drug delivery systems. In this chapter, we demonstrated the number of studies published in recent years that used carbon nanomaterials as adsorbents. Furthermore, this chapter discusses essential features of adsorption and different nanocarbon carbon composite material, such as the contrast between physical and chemical absorption. Furthermore, diverse carbon nanomaterial synthesis such as AC–FeO −Cu and Bimetallic FeO −Cu/algae activated carbon composites AC–Fe0 −Cu methodologies, functionalization, and characteristics are provided and logically addressed.

The study of carbon-based materials (CBMs) have grasped the attention of scientists from various field of science all around the world, like bio-sensing, cancer therapy, drug delivery, etc. This is due to the unique physical, chemical, and biological properties which includes thermal, mechanical, electrical, optical, antibacterial and antimicrobial activity. Various types of carbon-based materials like carbon fiber (CF), carbon nanotubes (CNT), graphene, carbon black (CB), activated carbon (AC), carbon dots/graphene quantum dots (CDs/GQDs), graphene oxide (GO), etc. have been investigated for various bio-medical applications which shows unique biological properties.

Carbon materials have been known since early human activities for heating purposes and basic daily life. With the development and the industrial revolution, the need for carbon materials for energy and scientific developments became inevitable. The diverse forms of carbon materials include cheap allotropy such as graphite and expensive such as diamond. The synthesis strategies are divided into natural and laboratory. The synthesis of carbon nanotubes in different forms has added many applications to the field. Moreover, graphene and its doped forms are considered a huge expansion into the chemistry of carbon materials. Here in this chapter, we discuss the fundamentals of the synthesis strategies of carbon materials.

Surface modification and engineering is the science that deals with modification involving the surface area of any material especially solids. The act of surface modification is done by bringing changes in physical, chemical or biological characteristics that are different from the original ones. The main objective of this technique is to improve performance of materials that interacts with the environment as the interaction can degrade the surface over a period of time. The significant improvement required would be to resist damages that are caused by wear, corrosion, fatigue, creep, etc. A rising demand for an alternative material for applications in engineering sectors for the want of minimizing structural weight has resulted in a prospective growth of composites. The demand is due to requirement of reduction in structural weight that would create a tremendous positive impact on energy efficiency. The major challenge in engineering sector is to achieve a competitive structure as light as possible. The materials that are micro nano-sized, incorporates many special properties that are widely used in various fields. An adsorbent is a substance used to adsorb particles from liquid or gas resulting in the betterment of the materials, which can harm the environment. The structure of activated carbon adsorbents with its pore size and surface properties aids to provide high efficacy and safety.

Nanoscale materials represent a new class of materials with extremely broad application prospects. Their development and utilization are intricately intertwined with societal progress. Nanomaterial adsorbents possess distinctive attributes, including a large specific surface area, a quantum size effect, and special surface properties. Therefore, it exhibits excellent adsorption performance. Compared with other traditional adsorbents, the application prospects of nanomaterial adsorbents in the environmental field are more attractive. This chapter elucidates the types, synthesis and, characterization of nanomaterial adsorbents according to their properties. Combined with the application of relevant examples in the environment, the corresponding nanoscale adsorbents are briefly introduced. Furthermore, the application of nanomaterial adsorbents in environment treatment was prospected.

Adsorption is a significant phenomenon that underlies a variety of crucial technical and environmental processes. There is no question about the importance of adsorption in protecting the environment and the industrial sector. Additionally, the first stage in many catalytic processes is adsorption of reactants over the catalyst. Therefore, numerous attempts have been made to explore the various adsorption process elements. However, a vital stage in the design and operation of adsorption equipment is having the working grasp of adsorption equilibrium and kinetics. To comprehend the adsorption equilibrium and kinetics, several different isotherms and kinetics models have been created. This chapter makes an effort to present an overview of a particular set of theories, isotherms and kinetic models used to describe adsorption events at the gas–solid interface. This chapter is split into two sections: the first section covers the theories and models (kinetics). The models that are used to analyze the isotherms of adsorption are the main topic of the second section.

Food products may be adulterated by the use of low-cost look-alike materials, low-quality materials, dilution of the original product, incorrect labeling of the material’s age and origin, and low-quality materials. The majority of dishonest traders base their decision to illegally adulterate their goods to increase sales on these four main criteria. Adsorption technology is one of these strategies that is effective and inexpensive. A special diagnostic technique for determining the chemical make-up of food contaminants is DESI mass spectrometry (MS). Adsorption, a powerful technology that can separate complex mixtures under delicate working conditions, is frequently required in the food processing industry. Among these techniques, the adsorption method emerged as an efficient and cost-effective way of eliminating from the food sector both organic and inorganic allergens such as synthetic colorants and organic contaminants like methylene blue, benzene, phenols, and methyl orange. The study also examines the adsorption process’s kinetics, isotherms, and mechanism, which can be used to effectively extract and concentrate additives or adulterants from extracts or the food products or wastewater produced by agricultural operations and the food industry.

Micropollutant (MP) contamination of water resources has sparked extensive environmental research. These MPs are frequently found in sewage, groundwater, wastewater, drinking water and surface water. This chapter gives the brief overview of the isotherms of MPs from aqueous solution from various adsorbents such as agricultural solid wastes, activated carbons, clays, and metal–organic-framework. Several isotherm models including Langmuir, Temkin, Freundlich, Dubinin- Radushkevich, Sips, Redlich-Peterson and Toth isotherm were discussed. This chapter demonstrates that the equilibrium graph fits the Langmuir isotherm in most cases and has found successful application in many monolayer adsorption sorption processes. Most of the literatures available perform batch process but this review provides the platform for developing continuous flow systems with large-scale applications at the small-scale also. The majority of the reported studies are done in batch mode, but this review provides a foundation for designing continuous flow systems with industrial applications at the commercial level as well.

The biggest issue in the globe is the environmental pollution, mainly from heavy metals and minerals from industrial effluents. Their concentration has reached risky levels due to the widespread anthropogenic activities such as industrial operations, mining, agricultural processes, and industrial waste materials. Several adsorbents have been utilised to remove heavy metals in recent years due to the rising pollution levels. Industrial effluent contains heavy metals such as Ni, Cr, Pb, Zn, Ar, Cr, Se, and U and other organic pollutants. Adsorbents have been used in the variety of successful heavy metal removal procedures because it is highly straightforward, affordable, efficient, and adaptable. It has emerged as the method of choice for removing hazardous pollutants from wastewater. Here, we discuss about how to remove heavy metals from wastewater using freshly prepared nanoparticles. The good investigation would be useful for figuring out how to conduct adsorption–desorption cycles for the removal of heavy metal from the water sources.

Pesticides represent a major class of water contaminants that are released in huge amounts to water bodies through agricultural activities. The accumulation of pesticides in soil and water causes severe health problems including endocrine disruption, damage of the kidney, liver, and other body organs, reproductive problems, and cancer. It is crucial to remove pesticides from the environment to protect biodiversity and reduce their hazardous effect on human beings. Adsorption is the most simple, practical, economical, feasible, and efficient method to remove pesticides from the environment. Carbon-based nanomaterials are gaining an increasing upsurge of interest as effective adsorbent materials due to their high surface area, biocompatibility, thermal stability, and high adsorption efficiency. The application of various carbon-based nanomaterials such as graphene, carbon nanotubes, chitosan, and cellulose has been demonstrated in this chapter for the development of efficient adsorbent material/membrane for the removal of all types of pesticides present in water. The regeneration of these materials can be performed through the desorption of pesticides and several recycling runs have been reported using these materials under mild conditions.

The color of the water is the most important and evident indicator of water quality parameter. It may not only be unsettling visually, but also the sign of contamination. Adsorption is the most widely used dye removal technology since it is straightforward, economical and very successful method. This chapter give current information on the most extensively research for the dyes adsorption and desorption methods. Illustrations are provided for the impacts of the initial dye concentration, pH, adsorbent dose, particle size and temperature. Likewise, potential eluents might be used to wash out contaminants from adsorbent materials. In this chapter, the adsorption and desorption investigations of dyes Methylene Blue, Congo Red, Malachite Green and Crystal Violet are discussed.

The availability of clean water is of pressing concern in developing countries and has been a key area of focus for research and development worldwide. The sixth Sustainable Development Goal of the United Nations emphasizes the need for clean water. Aromatic hydrocarbons are emerging organic contaminants that are being found frequently in drinking water, municipal wastewater, and surface water. Conventional wastewater treatment plants have been shown to have limited efficiency in removing these trace pollutants from water. Due to advantages including cost, effectiveness, simplicity of use, and reusability, the adsorption process is recognized as a promising water remediation technology for aromatic compound removal. Advanced carbon-based materials discussed in this chapter are two-dimensional materials, such as graphene and carbon nanotubes, and their composites. Their performance towards remediating monocyclic aromatic hydrocarbons (MAHs) and polycyclic aromatic hydrocarbons (PAHs) was explored using recent published results between 2007 and 2022 from reputable sources. The concluding section of the chapter presents recommendations for bridging knowledge gaps, as well as suggestions for future research direction.

Water deterioration and the scarcity of pure drinking water are the long-haul global problems faced by humanity. To keep the aquatic environment clean, toxic organic and inorganic contaminants must be removed from the water bodies. Even in micromolar concentrations, these contaminants can harm the environment and human health. The salinity levels of seawater are steadily rising due to global warming and climate change, which reduce the amount of freshwater available for domestic and industrial purposes. The water treatment technique not only has to eliminate the pollutants but also significantly desalinate the water. Carbon nanomaterials such as graphene, carbon nanotubes, fullerenes, graphene, graphitic carbon nitride and nanodiamonds are excellent materials for water purification due to their antifouling property, self-cleaning properties, easy modification, large specific surface area, high chemical stability, porosity and simplicity of regeneration and reusability. This chapter presents a comprehensive overview of the state-of-the-art carbon nanomaterials, including significant recent and past advancements and plans for their application in water treatment.

In this article, the nonlinear vibrations of single-walled carbon nanotubes were discussed. The governing equations of each layer are connected with those of its neighboring layers via the Van der Waals interlayer forces. By comparing the new results to those from earlier research, the effects of changes in the geometrical parameters of the nanotubes and the material constants of the elastic media around them on the vibration characteristics are studied. The variational iteration technique (VIM), the Adomian decomposition method (ADM), and the new homotopy perturbation method are compared. These strategies are solid and effective for resolving various linear and nonlinear differential equations that can appear in various branches of research and engineering. Also contrasting with numerical simulations are our results. The answers derived using these three methods and a numerical solution agrees extremely well. Please be aware that your name and affiliation and if applicable those of your co-author(s) will be published as presented in this proof. If you want to make any changes, please correct the details now. Please note that after publication corrections won’t be possible. Due to data protection we standardly publish professional email addresses, but not private ones, even if they have been provided in the manuscript and are visible in this proof. If you or your co-author(s) have a different preference regarding the publication of your mail address(s) please indicate this clearly. If no changes are required for your name(s) and affiliation(s) and if you agree with the handling of email addresses, please respond with “Ok”. The author and co-author names and affiliations are correct.