Chemists develop a simple, easy-to-use method to break down pollutants in water

February 8, 2018, Martin-Luther-Universität Halle-Wittenberg
water
Credit: George Hodan/public domain

Chemists from Martin Luther University Halle-Wittenberg (MLU) have determined how stubborn pollutants in water can be disintegrated easily and cost-effectively. The process requires only a green LED light, a catalyst and vitamin C, and can produce hydrated electrons that reliably destroy the pollutants in the water. Until now, complex laser systems were required. The study was recently published in Angewandte Chemie.

Researchers in photochemistry use to initiate chemical reactions. "The idea is that light penetrates a molecule and triggers a reaction there," says chemist Martin Goez from MLU, whose research group developed the new process. Of particular interest are electrons, which are released by the light energy from their molecular compound in vitamin C and then exist freely in the water. "These so-called hydrated electrons are extremely reactive and can, for example, break down pollutants. The advantage over other substances is that the electrons completely disappear after the , meaning they do not leave any harmful residues," Goez continues. These special electrons can even react with very stable substances and break them down into their individual components.

Until now, expensive and complex high-power lasers were required to generate these types of electrons. Using this kind of equipment is also linked to strict safety precautions. In contrast, the development made by Goez' team at MLU is significantly easier and more cost-effective. "Our system consists of a standard green light-emitting diode, traces of a metal complex that act as a catalyst and vitamin C. This method can be taught to undergrad students at a very early stage," says Goez. The research group tested the new method on chloroacetic acid, an extremely toxic, stable substance. With their system, the researchers were able to destroy the compound into harmless components. They were also able to demonstrate that their cost-effective alternative could generate just as many electrons as a high-power laser.

The development by the MLU's research group is not only suitable for decomposing harmful chlorides or fluorides, the approach can also be applied to many other photochemical reactions that are difficult to initiate by other means.

Explore further: New efficient catalyst for key step in artificial photosynthesis

More information: Robert Naumann et al, Generating Hydrated Electrons for Chemical Syntheses by Using a Green Light-Emitting Diode (LED), Angewandte Chemie International Edition (2017). DOI: 10.1002/anie.201711692

Related Stories

The unbelievable speed of electron emission from an atom

November 13, 2017

In a unique experiment, researchers have clocked how long it takes for an electron to be emitted from an atom. The result is 0.000 000 000 000 000 02 seconds, or 20 billionths of a billionth of a second. The researchers' ...

Recommended for you

Nanodiamonds as photocatalysts

October 19, 2018

Climate change is in full swing and will continue unabated as long as CO2 emissions continue. One possible solution is to return CO2 to the energy cycle: CO2 could be processed with water into methanol, a fuel that can be ...

Producing defectless metal crystals of unprecedented size

October 19, 2018

A research group at the Center for Multidimensional Carbon Materials, within the Institute for Basic Science (IBS), has published an article in Science describing a new method to convert inexpensive polycrystalline metal ...

Shining light on the separation of rare earth metals

October 18, 2018

Inside smartphones and computer displays are metals known as the rare earths. Mining and purifying these metals involves waste- and energy-intense processes. Better processes are needed. Previous work has shown that specific ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.