
Simultaneous photocatalytic hydrogen generation and dye degradation using a visible light active metal–organic framework. Creidt: Alina-Stavroula Kampouri/EPFL
Researchers at EPFL’s Institute of Chemical Sciences and Engineering 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.
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.
Learn more: New material cleans and splits water
The Latest on: Photocatalytic system
via Google News
The Latest on: Photocatalytic system
- Direct observation of charge separation in an organic light harvesting system by femtosecond time-resolved XPSon February 19, 2021 at 2:19 am
Understanding ultrafast dynamics of photon-to-charge conversion is paramount for optimising light-harvesting systems. Here, the authors use femtosecond time-resolved X-ray photoemission spectroscopy ...
- Applications of Polyimide Nano-Aerogelson February 18, 2021 at 5:54 am
Nano-aerogels have been incorporated into thermal insulation materials due to their low thermal conductivity and photocatalytic devices ... of PI-nano-aerogels into the thermal protection system of ...
- Organic polymer dots boost green hydrogen productionon February 15, 2021 at 1:44 am
“But getting these components to work well together in a photocatalytic system is challenging.” To investigate how well the three components worked together, Tian and his colleagues used spectroscopic ...
- Metal–organic frameworks embedded in a liposome facilitate overall photocatalytic water splittingon February 14, 2021 at 4:00 pm
Fig. 1: Structure of the LP–MOF for overall photocatalytic water splitting and the proposed ‘Z-scheme’ electron-transfer chain in the LP–MOF system. Fig. 2: HER-MOF and WOR-MOF structures.
- Producing more sustainable hydrogen with composite polymer dotson February 12, 2021 at 2:32 am
But getting these components to work well together in a photocatalytic system is challenging,” says Haining Tian, Associate Professor (Docent) of Physical Chemistry at Uppsala University.
- Producing more sustainable hydrogen with composite polymer dotson February 11, 2021 at 4:00 pm
But getting these components to work well together in a photocatalytic system is challenging," says Haining Tian, Associate Professor (Docent) of Physical Chemistry at Uppsala University.
- Applied UV Announces Acquisition of the Airocide(R) Technology Platform for Airborne Pathogen Reductionon February 9, 2021 at 4:54 pm
The Airocide® system, originally developed for NASA ... owns the exclusive world-wide rights to a unique NASA commissioned photocatalytic oxidation technology that is the foundation of the ...
- New nanocoating a breakthrough for hydrogen fuelon February 9, 2021 at 1:58 am
Researchers have developed a very effective protection strategy for narrow bandgap semiconductors, stabilizing them during photoreactions.
- IIT Jodhpur Develops New Sterilisation Systemon January 27, 2021 at 8:10 am
Indian Institute of Technology (IIT Jodhpur) has developed a new sterilization system called Advanced Photocatalytic Oxidation Conveyor System named or APCOC to sterilize the surfaces of food ...
via Bing News