New! Sign up for our free email newsletter.
Science News
from research organizations

New material cleans and splits water

Date:
November 5, 2018
Source:
Ecole Polytechnique Fédérale de Lausanne
Summary:
Researchers have developed a photocatalytic system based on a material in the class of metal-organic frameworks. The system can be used to degrade pollutants present in water while simultaneously producing hydrogen that can be captured and used further.
Share:
FULL STORY

Some of the most useful and versatile materials today are the metal-organic frameworks (MOFs). MOFs are a class of materials demonstrating structural versatility, high porosity, fascinating optical and electronic properties, all of which makes them promising candidates for a variety of applications, including gas capture and separation, sensors, and photocatalysis.

Because MOFs are so versatile in both their structural design and usefulness, material scientists are currently testing them in a number of chemical applications. One of these is photocatalysis, a process where a light-sensitive material is excited with light. The absorbed excess energy dislocates electrons from their atomic orbits, leaving behind "electron holes." The generation of such electron-hole pairs is a crucial process in any light-dependent energy process, and, in this case, it allows the MOF to affect a variety of chemical reactions.

A team of scientists at EPFL Sion led by Kyriakos Stylianou at the Laboratory of Molecular Simulation, have now developed a MOF-based system that can perform not one, but two types of photocatalysis simultaneously: production of hydrogen, and cleaning pollutants out of water. The material contains the abundantly available and cheap nickel phosphide (Ni2P), and was found to carry out efficient photocatalysis under visible light, which accounts to 44% of the solar spectrum.

The first type of photocatalysis, hydrogen production, involves a reaction called "water-splitting." Like the name suggests, the reaction divides water molecules into their constituents: hydrogen and oxygen. One of the bigger applications here is to use the hydrogen for fuel cells, which are energy-supply devices used in a variety of technologies today, including satellites and space shuttles.

The second type of photocatalysis is referred to as "organic pollutant degradation," which refers to processes breaking down pollutants present in water. The scientists investigated this innovative MOF-based photocatalytic system towards the degradation of the toxic dye rhodamine B, commonly used to simulate organic pollutants.

The scientists performed both tests in sequence, showing that the MOF-based photocatalytic system was able to integrate the photocatalytic generation of hydrogen with the degradation of rhodamine B in a single process. This means that it is now possible to use this photocatalytic system to both clean pollutants out of water, while simultaneously producing hydrogen that can be used as a fuel.

"This noble-metal free photocatalytic system brings the field of photocatalysis a step closer to practical 'solar-driven' applications and showcases the great potential of MOFs in this field," says Kyriakos Stylianou.


Story Source:

Materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Content may be edited for style and length.


Journal Reference:

  1. Stavroula Kampouri, Tu N. Nguyen, Mariana Spodaryk, Robert G. Palgrave, Andreas Zu?ttel, Berend Smit, Kyriakos C. Stylianou. Concurrent Photocatalytic Hydrogen Generation and Dye Degradation Using MIL-125-NH2 under Visible Light Irradiation. Advanced Functional Materials, 2018 DOI: 10.1002/adfm.201806368

Cite This Page:

Ecole Polytechnique Fédérale de Lausanne. "New material cleans and splits water." ScienceDaily. ScienceDaily, 5 November 2018. <www.sciencedaily.com/releases/2018/11/181105081705.htm>.
Ecole Polytechnique Fédérale de Lausanne. (2018, November 5). New material cleans and splits water. ScienceDaily. Retrieved July 14, 2024 from www.sciencedaily.com/releases/2018/11/181105081705.htm
Ecole Polytechnique Fédérale de Lausanne. "New material cleans and splits water." ScienceDaily. www.sciencedaily.com/releases/2018/11/181105081705.htm (accessed July 14, 2024).

Explore More

from ScienceDaily

RELATED STORIES