A research team from several US universities has developed a dual-purpose photocatalyst that purifies pesticide-contaminated water while producing hydrogen. That's according to a recent study published in ACS Catalysis, a journal of the American Chemical Society that specializes in the innovation and development of catalysts.
The study of these photoactive catalysts comes as part of the globally challenging water pollution control project, as well as the pursuit of green hydrogen fuel, a clean and renewable fuel.
The team combined both oxidation to purify water and reduction to produce hydrogen by splitting water (Getty Images)
Combined redox
In obtaining the photocatalytic system, the research team relied on combining both oxidation to purify water and reduction to produce hydrogen by splitting water.
Study leader Kyriakos Stiliano, assistant professor of chemistry at Ohio State University, said: "We can combine redox in one process to achieve an effective photocatalytic system, as oxidation occurs through a photolysis reaction, and reduction occurs through the reaction in the hydrogen production process."
According to the press release of Oregon State University, catalysts are substances that increase the rate of chemical reaction without subjecting themselves to any permanent chemical change, most notably photocatalysts, which are substances that absorb light to reach a higher energy level, which can be used to break down organic pollutants through oxidation.
The statement notes that light catalysts have different applications, most notably self-cleaning coatings for walls, floors, ceilings and furniture that are resistant to stains and odors.
The team developed titanium dioxide photocatalysts to purify water (Getty Images)
Development of a catalyst from an organic metal frame
In this study, the team developed titanium dioxide photocatalysts derived from metal-organic frameworks (MOFs), which are porous crystals made up of positively charged metal ions surrounded by organic molecules.
Gases can be stored on these crystals, such as hydrogen, natural gas or carbon dioxide, and can then help eliminate greenhouse gases, such as absorbing, sequestering and storing carbon dioxide before it reaches the atmosphere.
On the other hand, these MOFs purify water from pollutants, as well as desalinate seawater, a recent discovery in the use of MOFs.
The discovery of MOFs is due to the Jordanian-American scientist Professor Omar Yaghi, who discovered them in the early nineties of the last century.
According to this study, the researchers were able to obtain photocatalysts by high heating during the calcination of MOFs' calcination, through which semiconductor materials such as titanium dioxide, the most commonly used photocatalyst, can be generated.
According to the Encyclopedia Britannica, calcination is a process in which solids are heated to a high temperature for the purpose of removing volatile substances, oxidizing part of the mass, or making them friable. Therefore, calcination is sometimes considered a purification process.
The catalyst developed helps produce hydrogen by splitting water via photocatalysis (Pixaby)
Catalytic hydrogen production
The press release says that the catalyst developed produces hydrogen by splitting water via photocatalysis, which is cleaner and more sustainable than the traditional method of deriving hydrogen from natural gas through a carbon dioxide production process known as methane vapor reform.
Hydrogen serves many scientific and industrial purposes, in addition to its energy-related roles, and its use in automotive fuel cells and in the manufacture of many chemicals, including ammonia, and in metal refining and plastic production.
Water is "a rich source of hydrogen, and photocatalysis is a way to harness abundant solar energy for hydrogen production and environmental remediation," says Stiliano.
"We show in this study that through photocatalysis renewable fuels can be produced while removing organic pollutants, or converted into useful products," Stiliano said.