Scientists tackle indoor air pollution

People on average spend nearly 90% of their time indoors and, especially in the cold winter months in Canada, this statistic can be even higher. With all that time spent indoors, filtering out pollutants from indoor air is very important for the health of Canadians.

Researchers from the College of Engineering at the University of Saskatchewan (USask) have been developing a catalyst for a new type of air purifying technique that would clean air at room temperature.

“Ozone is one of the strongest purifying agents that has been used in the water treatment industry for a long time. In our research, we use ozone and an effective catalyst to purify indoor air from Volatile Organic Compounds or VOCs,” explained PhD student Mehraneh Ghavami.

Ghavami and co-researcher Dr. Jafar Soltan used the HXMA beamline at the Canadian Light Source (CLS) at USask to discover which types of metal catalysts would work best for eliminating pollutants out of the air and recently published their findings.

Their air purifying system uses ozone gas and a catalyst to remove indoor air pollutants and turn them into carbon dioxide and water.

Read more on the Canadian Light Source website

Image: Mehraneh Ghavami using the CLS’ HXMA beamline

Credit: CLS

Unravelling the history of 15th Century Chinese porcelains

Researchers from French and Spanish Institutions used the combination of two synchrotron light characterization techniques to study Chinese blue-and-white Ming porcelains. They were able to identify the firing temperature by determining the porcelain’s pigments and the reduction-oxidation media conditions during their production. The approach they used can also be applied on a broad range of modern and archaeological ceramics to elucidate their production technology.

Pottery is found at the majority of archaeological sites dating from the Neolithic period, when first human settings appear, onwards. Which makes it a major focus of study in archaeological science.  The study of style and production of ceramics is central to the historical reconstruction of a site, region and period.

More specifically, ceramic technological studies look to reconstruct the production technology of ceramics, by determining the selection and preparation of the raw materials, the formation of ceramics, treatment and decoration of the ware’s surface and the firing atmosphere. All of this is possible thanks to the scientific techniques available nowadays.

In a recent publication, researchers from French and Spanish Institutions used the combination of two synchrotron light characterization techniques to study Chinese blue-and-white Ming porcelains. These characteristic porcelains, whose production flourished around the 14th century, are decorated under the glaze with Cobalt-based blue pigments that provided their distinctive blue decorations and produced during a one-step firing at high temperatures.

They were able to identify the firing temperature by determining the porcelain’s pigments and the reduction-oxidation media conditions during their production. The approach they used can also be applied on a broad range of modern and archaeological ceramics to elucidate their production technology.

Read more on the ALBA website

Image: Porcelain Jar with cobalt blue under a transparent glaze (Jingdezhen ware). Mid-15th century

Credit: Metropolitan Museum of Art.

Fe Cations Control the Plasmon Evolution in CuFeS2 Nanocrystals

Research on the synthesis of CuFeS2, an exciting semiconductor, outlines a method to verify its phase purity and investigate its properties.

Plasmonic semiconductor nanocrystals have become an appealing avenue for researching nanoscale plasmonic effects due to their wide spectral range (visible to infrared) and great tunability compared to traditional precious metal nanocrystals. CuFeS2 is an exciting semiconductor that has a prominent plasmon absorption band in the visible range (∼498 nm). In this work, the researchers determined the origin of the plasmonic behaviour in CuFeS2 by characterizing the nucleation and growth stages of the reaction through a series of ex situ and in situ probes (e.g., X-ray absorption spectroscopy and X-ray emission spectroscopy). They showed that the plasmon formation is driven by band structure modification from Fe(II) incorporation into the nanocrystals. Mixed oxidation state of Cu(I)/Cu(II) and Fe(II)/Fe(III) was observed.  Using these results, the researchers proposed a reaction mechanism for synthesis of CuFeS2 and outlined a method to verify the phase purity of the material.

Read more on the CHESS website