GUWAHATI, Oct 25: Researchers at the Indian Institute of Technology-Guwahati (IIT-G) are developing novel materials that can use sunlight to split water into energy-rich hydrogen and oxygen.
The research team led by Prof. Mohammad Qureshi from the department of chemistry, IIT-G developed non-noble metal catalysts that are as good as expensive metals in splitting water in photo electro chemical (PEC) cells.
PEC cells use solar energy to split simple and safe compounds such as water into hydrogen and oxygen, hydrogen being a high-energy fuel that can be stored and used as needed. These cells are therefore considered the ‘holy grail’ to a carbon-free hydrogen economy.
The team reported their recent findings in the peer-reviewed journal of the American Chemical Society, Journal of Physical Chemistry Letters. The paper has been co-authored by Prof. Qureshi and Suhaib Alam.
Elaborating on the importance of the research, Prof. Qureshi said, “Despite the promise, PEC cells are not yet a practical solution to the energy crisis because of the scientific bottlenecks such as the sluggishness of the water-oxidation process. Catalysts are used to activate the water-splitting process but these catalysts are expensive metals such as platinum, iridium and ruthenium, among others, which render the cells impractical.”
“The combination of semiconductors which are impeded by their energy level mis-match for carrier transportation can use this approach as a model system. Semiconductors with sluggish water oxidation kinetics can transform into materials with faster kinetics,” a statement from IIT-G said.
Explaining further, Prof. Qureshi said, “We have developed a ternary catalyst that comprises cobalt-tin layered-double hydroxides (LDH) and bismuth vanadate, which forms a p-n junction semiconductor with graphene bridges, and have shown that the catalyst, when used as a photoanode, is able to split water easily to produce hydrogen and oxygen.”
The research team believes that their findings will help us understand the mechanism of hetero-structured photoanodes and inspire the design of cheaper photoelectrode systems for improved water oxidations.
The researchers are now in the process of developing a prototype device to test their photoanode in practical PEC cells.