Tag: visible light

Effective and environmentally friendly removal of pharmaceuticals from wastewater under visible light

Effective and environmentally friendly removal of pharmaceuticals from wastewater under visible light

The research team working under the leadership of Prof. Anna Zielińska-Jurek from the Faculty of Chemistry at Gdańsk University of Technology, in cooperation with scientists from ASTRA beamline, developed and characterized a new semiconductor material based on bismuth orthovanadate (BiVO4) and copper oxide sub-nanoclusters (CuOx). This material, when exposed to visible light, is able to effectively remove pharmaceuticals in water. Measurements made at the SOLARIS synchrotron using X-ray absorption spectroscopy (XAS) revealed the oxidation state of copper oxides. The research results were published in the journal “Separation and Purification Technology” from Elsevier publisher.

The rapid development of medicine and the pharmaceutical industry has made pharmaceutical pollution one of the greatest environmental dangers. Some of the most frequently detected pharmaceuticals in Polish sewage are naproxen, a popular painkiller, and ofloxacin, an antibiotic. These compounds, found in rivers, lakes or seas, are persistent and not susceptible to biological degradation, and conventional methods used in sewage treatment plants are insufficient to remove them.

A promising way to remove pharmaceuticals from the aqueous phase is their degradation in the process of heterogeneous photocatalysis supported by peroxymonosulfate ions (HSO5−, PMS). These processes are based on the generation of highly reactive radicals under sunlight, which, as a result of reaction with pollutants, are able to purify water.

Read more on Solaris website

Ultrafast and tunable

Ultrafast and tunable

Terahertz-to-visible light conversion for future telecommunications

A study carried out by a research team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the Catalan Institute of Nanoscience and Nanotechnology (ICN2), University of Exeter Centre for Graphene Science, and TU Eindhoven demonstrates that graphene-based materials can be used to efficiently convert high-frequency signals into visible light, and that this mechanism is ultrafast and tunable, as the team presents its findings in Nano Letters (DOI: 10.1021/acs.nanolett.3c00507). These outcomes open the path to exciting applications in near-future information and communication technologies.

The ability to convert signals from one frequency regime to another is key to various technologies, in particular in telecommunications, where, for example, data processed by electronic devices are often transmitted as optical signals through glass fibers. To enable significantly higher data transmission rates future 6G wireless communication systems will need to extend the carrier frequency above 100 gigahertz up to the terahertz range. Terahertz waves are a part of the electromagnetic spectrum that lies between microwaves and infrared light. However, terahertz waves can only be used to transport data wirelessly over very limited distances. “Therefore, a fast and controllable mechanism to convert terahertz waves into visible or infrared light will be required, which can be transported via optical fibers. Imaging and sensing technologies could also benefit from such a mechanism,” says Dr. Igor Ilyakov of the Institute of Radiation Physics at HZDR.

Read more on the HZDR website

Image: A graphene-based material converts incoming terahertz pulses (from above) into visible light in an ultrafast and controllable manner – optimal for data transport in optical fibers.

Credit: B. Schröder/HZDR