When manufacturing a material, imperfections, like holes in Swiss cheese, arise spontaneously and without any control. According to a press release, research by the Spanish National Research Council (CSIC) has led to directing the growth of porous cavities appearing on gold (Au) nanostructures. The finding was published in the journal Nanotechnology. The research team developed a new synthesis technique for nanoporous gold films by utilizing plasma. Lead CSIC researcher Alberto Palmero, who also teaches at the Institute of Materials Science of Seville, said "Until now, the synthesis of this material did not allow a precise control of the structure ".
Plasma is an ionized gas, filled with ions and electrons, which is used to pulverizes the surface of a gold block used in the research. By altering the properties of the plasma, Palmero’s team was able to direct powdered gold atoms towards another surface to promote the formation of gold structures on which it has been possible to control the size, arrangement, and depth of nanopores .
Unlike conventional gold used in jewelry, the nanoporous version is characterized by generating a high catalytic activity in oxidation reactions. This allows its use to remove gaseous pollutants and turn them into substances less harmful to the environment. The catalytic activity of gold occurs inside their nanocavities. The importance of this research, therefore, lies in the possibility of controlling the nanoporosity of the material and optimizing the decontamination process.
Palmero spoke of carbon monoxide (CO), saying "When this toxic gas, of great polluting power, penetrates the nanostructure and comes into contact with its surface, the energy needed for activation is reduced so that it can oxidize and turn into carbon dioxide (CO2). Said the CSIC researcher, “…the possibility of synthesizing gold with controlled nanoporosity opens a new door to technological applications in fields as diverse as the elimination of gaseous pollutants, the development of sensors, the petrochemical industry and fuel cells, among others". Furthermore, Palmero emphasizes that "this technique can easily be implemented industrially."