Advanced ecological applications of clay minerals

Abstract

Nowadays advanced materials derived from clay minerals with potential applications in many diverse fields are under study and development following certain Nanoscience and Nanotechnology concepts [1]. So, novel approaches are being applying for the use of this natural resource in a rational and ecological way to prepare nanostructured materials and, vice versa to apply them in turn to reduce environmental impact. In this context some of them can be utilized, for instance, in the removal of pollutants and other kind of repair and green activities. In this context, clay minerals represent a paradigmatic example because they belong to the most widely spread type of silicates that are present in soils and ore deposits, being exploited since the dawn of humanity. In this lecture it will be introduced recent contributions from our Research Group at the Materials Science Institute of Madrid (CSIC) related to diverse clay-based nanostructured materials, showing their ability for efficient elimination in a green way of pollutants, such as hexavalent chromium, radionuclides, pesticides, drugs in urban water, etc. [2,3]. Also, it will be considered examples of clay-based biohybrids provided of specific and predetermined behavior crucial to design materials of interest as sensing agents for selective ion-recognition, virus particles immobilization for improved adjuvant of vaccines or DNA non-viral transfection [4]. Finally, this lecture will also show the production of clay-carbonaceous materials containing carbon nanotubes and graphenes of great interest for the fabrication of conducting electrodes for potential uses in energy generation and storage as well as in biosensing devices. This methodology may open the way to a future large scale production of graphene-clay based materials in an ecological way [5]. The synthetic strategies here discussed concern layered smectites and vermiculites, as well as microfibrous silicates, such as sepiolite and palygorskite, which can be used as basic building units for the design and preparation of both structural and functional materials.