Environmental Applications of Nanomaterials

The use of nanomaterials is important in environmental science and technology in terms of their applications in green chemistry, pollution prevention, remediation of contaminated soils and water, and sensing and detection of pollutants. These applications are directed towards environmental improvement and pollution control. 

One of the major breakthroughs in nanotechnology is the use of nanomaterials as catalysts for environmental applications [149]. Nanomaterials have been developed to improve the properties of catalysts, enhance reactivity towards pollutants, and improve their mobility in various environmental media [150]. Nanomaterials offer applications to pollution prevention through improved catalytic processes that reduce the use of toxic chemicals and eliminate wastes. Nanomaterials also offer applications in environmental remediation and, in the near future, opportunities to create better sensors for process controls. 

This section covers environmental applications of nanomaterials insofar as they are directly applied to the pollutant of interest. The photocatalytic degradation of organic pollutants and remediation of polluted soils and water are discussed here. The high surface areas and photocatalytic activities of semiconductor nanomaterials have attracted many researchers. Semiconductor nanomaterials are commercially available, stable, and relatively nontoxic and cheap. Prominent examples that are discussed are metal oxides such as Ti02 and ZnO and a variety of Fe-based nanomaterials. 

Bimetallic nanomaterials such as Pd/Fe, Ni/Fe, and Pd/Au are also active catalysts for the degradation of organic contaminants, including halogenated pesticides, nitroaromatics, polychlorinated biphenyls, and halogenated aliphatics (ethenes and methanes) [151]. 

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G. E. Fryxell, G. Cao, eds, Environmental Applications of Nanomaterials Synthesis, Sorbents and Sensors, Imperial College Press, London, 2007. 

A common theme throughout this volume involves the adsorption and interfacial, especially biointerfacial, behaviour of all of the above mentioned nanomaterials. For environmental and human protection, the adsorption of heavy metal ions, toxins, pollutants, drugs, chemical warfare agents, narcotics, etc. is often desirable. A healthy mix of experimental and theoretical approaches to address these problems is described in various contributions. In other cases the application of materials, particularly for biomedical applications, requires a surface rendered inactive to adsorption for long term biocompatibility. Adsorption, surface chemistry, and particle size also plays an important role in the toxicological behaviour of nanoparticles, a cause for concern in the application of nanomaterials. Each one of these issues is addressed in one or more contributions in this volume. 

Matzger AJ, Lawrence CE, Grubbs RH, Lewis NS (2000) Combinatorial approaches to the synthesis of vapor detector arrays for use in an electronic nose. J Comb Chem 2 301-304 Mauter MS, EUmelech M (2008) Environmental applications of carbon-based nanomaterials. Environ Sci Technol 42(16) 5843-5859... 

Mauler, M. S., Elimelech, M. (2008). Environmental Applications of Carbon-Based Nanomaterials. Environmental Science Technology, 42(16), 5843-5859. 

Electroanalytical chemistry and physical electrochemistry are of interdisciplinary nature. The electroanalytical chemistry focused on the analysis of life and environmental related systems. While physical electrochemistry focused more on the understanding of the interfacial and surface structures and the energy related system. Along with this background, we can classify the progresses made in electroanalytical chemistry and physical electrochemistry based on nanomaterials into two aspects understanding of the electrochemistry at the nanometer scale and the application of nanomaterials for electroanalysis. 

XPS has been used in almost every area in which the properties of surfaces are important. The most prominent areas can be deduced from conferences on surface analysis, especially from ECASIA, which is held every two years. These areas are adhesion, biomaterials, catalysis, ceramics and glasses, corrosion, environmental problems, magnetic materials, metals, micro- and optoelectronics, nanomaterials, polymers and composite materials, superconductors, thin films and coatings, and tribology and wear. The contributions to these conferences are also representative of actual surface-analytical problems and studies [2.33 a,b]. A few examples from the areas mentioned above are given below more comprehensive discussions of the applications of XPS are given elsewhere [1.1,1.3-1.9, 2.34—2.39]. 

This volume details work presented at the NATO Advanced Research Workshop entitled Pure and Applied Surface Chemistry and Nanomaterials for Human Life and Environmental Protection held in Kiev, Ukraine, September 14-17, 2005. A total of 39 selected works have been compiled detailing research in three categories all related to the surface chemistry of nanomaterials fundamentals, biomedical applications for human life, and environmental protection. 

While these techniques are widely used, they do not provide sufficient purity. Liquid phase purification is not an environmentally friendly process and requires corrosion-resistant equipment, as well as costly waste disposal processes. Alternative dry chemistry approaches, such as catalyst-assisted oxidation or ozone-eiuiched air oxidation, also require the use of aggressive substances or supplementary catalysts, which result in an additional contamination. Moreover, in many previous studies trial and error rather than insight and theory approaches have been applied. As a result, a lack of understanding and limited process control often lead to extensive sample losses of up to 90%. Because oxidation in air would be a controllable and enviromnentaUy friendly process, selective purification of carbon nanomaterials, such as CNT and ND, in air is very attractive. In contrast to current purification techniques, air oxidation does not require the use of toxic or aggressive chemicals, catalysts, or inhibitors and opens avenues for numerous new applications of carbon nanomaterials. 

For an industrial-scale production of carbon nanomaterials, it is important to use a simple and environmentally friendly purification method to selectively remove sp -bonded carbon from nanodiamond and amorphous carbon from nanotubes with minimal or no loss of diamond or nanotubes. In contrast to current purification techniques, which usually use mixtures of oxidizing acids, controlled air oxidation does not require the use of toxic or aggressive chemicals, catalysts, or inhibitors, thus opening avenues for numerous new applications of carbon nanomaterials. 

Magnetism of Earth, Planetary, and Environmental Nanomaterials Applications of magnetic nanoparticles... 

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