A research group of the University of Cordoba, linked to ceiA3, develops a system to prepare decontaminating materials able to remove nitrogen oxides from the air.
Nitrogen oxides are some of the main gases responsible for pollution, which generates serious health problems. Most are generated due to the use of fossil fuels, although others occur due to natural causes, such as bacterial decompositions, fires or storms. A research work from the University of Cordoba developed a methodology to prepare decontaminating materials from rice husk waste. Most of these decontaminating materials are applied to floorings and buildings. Their effectiveness is based on photocatalysis, that is, a mechanism by which pollutants are removed from the air by an oxidation process activated by solar energy.
Led by professor Luis Sánchez, the research group FQM 175 attached to the Research Institute on Fine Chemistry and Nanochemistry of the University of Cordoba developed these photocatalyst compounds, based on zinc oxide supported on silicon oxide. What is new is that rice husk waste has been used to "modulate the growth of zinc oxide particles on a nanometric scale and its sensitivity to nitrogen dioxide", which is a polluting gas with a high degree of toxicity.
Obtained by a process of grinding and calcination, the compounds "offered the highest efficiency and selectivity in the photochemical elimination of these gases in an inexpensive, simple and sustainable way so far."
In addition, laboratory-scale research shows these photocatalysts can make disappear the high concentration of these polluting gases during peak traffic hours in the cities. Moreover, the activity of these compounds is fully recoverable with water cleaning, so this research "will allow to implement the actual use of these decontaminants in large cities."
The research work was published in the Chemical Engineering Journal and has been financed from the MINECO MAT2017-88284-P project 2D and 3D Systems based on Hydrotalcites as Photocatalysts for the Elimination of NOx gases.