Newswise —

The problem of air pollution and its concentrated presence in urban areas is a current societal issue, with detrimental impacts on both the environment and human well-being. One reason for this pollution is the escalation in nitrogen oxide discharges, primarily attributed to the utilization of non-renewable energy sources.

Despite efforts to reduce gas emissions, photocatalysis is emerging as a solution for purifying air in urban areas. This technique involves creating semiconductors that, when exposed to ultraviolet light, trigger the degradation of pollutants upon contact, leading to a decrease in their concentration in the atmosphere.

The Chemical Institute for Energy and the Environment (IQUEMA) and the Department of Inorganic Chemistry and Chemical Engineering at the University of Cordoba have formed two research groups to develop these materials. The BioPrEn and Inorganic Chemistry groups have collaborated to create biodegradable materials that can anchor nanoparticles with photocatalytic properties, such as titanium dioxide, to increase their effectiveness in decontaminating the air.

According to researcher Eduardo Espinosa, the progress achieved through this project includes two main achievements. Firstly, the development of a biodegradable medium made from nanocellulose extracted from agricultural waste. Secondly, the creation of a surface modification technique that enhances the dispersion and immobilization of nanoparticles, resulting in increased photocatalytic activity.

This project's progress is two-fold: firstly, the creation of a sustainable material through the utilization of agricultural waste (contributing to the Circular Economy), and secondly, the simplification of the process of anchoring photocatalytic nanoparticles to this biodegradable medium. The benefits are exponential, as the material's porosity and three-dimensional structure enhance air decontamination by exposing more photocatalytic particles to ultraviolet light compared to opaque materials or those with only one exposed surface.

What is it like? Where is it used?

This material is light and has a low density, similar to construction insulation or corn puffs. When used for decontamination purposes, it can serve as a porous filter for gas streams, allowing them to pass through and be exposed to ultraviolet light, resulting in decontamination. As Eduardo Espinosa explains, industrial gas emissions can pass through this filter and come out almost completely free of nitrogen oxides.

The next step in this research would be to modify the photocatalytic particles to make them more sensitive to light from the visible spectrum, eliminating the need for ultraviolet light sources. This modification would enable the activation of photocatalytic power by sunlight alone, allowing this technology to be applied to textiles and other materials, thereby reducing gas concentration through exposure to sunlight only.

References:

Carrasco, Sergio & Espinosa Víctor, Eduardo & González, Zoilo & Cruz-Yusta, Manuel & Sánchez, Luis & Rodríguez, Alejandro (2023). Simple Route to Prepare Composite Nanocellulose Aerogels: A Case of Photocatalytic De-NO x Materials Application. ACS Sustainable Chemistry &Engineering. https://doi.org/10.1021/acssuschemeng.2c06170

Journal Link: ACS Sustainable Chemistry & Engineering