In a search for inexpensive clean energy, scientists have demonstrated how an inexpensive semiconductor material when tweaked generates hydrogen from water using sunlight. The likely key component in the transition to cleaner energy sources has long been touted to be hydrogen.

A new alloy of an inexpensive semiconductor material when immersed in water and exposed to sunlight enables the chemical bond between hydrogen and oxygen to be broken, allowing the energy carrier to be collected, scientists say.

As hydrogen is not abundantly available in a pure form on Earth, unlocking it from other compounds is the key crucial component in the transition to cleaner energy sources, scientists say. Hydrogen is not considered an energy source, but rather an energy carrier.

Currently, a large amount of electricity is needed to generate hydrogen by water splitting and the process entails a large amount of carbon dioxide emissions.

The new research by professors at the University of Kentucky Center for Computational Sciences and the University of Louisville Conn Center for Renewable Energy Research could change all that.

The scientists have found that an alloy of antimony (Sb) and gallium nitride (GaN) helps sunlight split water molecules into hydrogen and oxygen. Once they are separate, hydrogen can be collected. The process is called photoelectrochemical (PEC) water splitting.

When the catalyst is properly manufactured, one could buy it in a commercial store for making hydrogen in his backyard, Professor Madhu Menon of the University of Kentucky told IBTimes.

The research should attract the interest of other scientists across a variety of disciplines. Photocatalysis is currently one of the hottest topics in science. We expect the present work to have a wide appeal in the community spanning chemistry, physics and engineering, said Menon.

width=630

Hydrogen's potential utility in green tech initiatives is immense. It can be used to generate electricity, produce heat and run vehicles. It also has wide-ranging applications in science and industry. When combusted, hydrogen combines with oxygen to form water vapor as its only waste product, the report points out.

The GaN-Sb alloy is the first simple, easy-to-produce material to be considered a candidate for photoelectrochemical water splitting.

According to another researcher, Professor Mahendra Sunkara of the University of Louisville Conn Center for Renewable Energy Research, the GaN-Sb alloy has the potential to convert solar energy into an economical, carbon-free source for hydrogen.

Hydrogen production now involves a large amount of CO2 emissions... Once this alloy material is widely available, it could conceivably be used to make zero-emissions fuel for powering homes and cars and to heat homes, said Sunkara.

The components of the alloy, gallium nitride and antimony, are widely used in the electronics industry. While gallium nitride is used to make bright-light LEDs, antimony has been used as metalloid element in the microelectronics industry.

Previous research on PEC [photoelectrochemical] has focused on complex materials, said Menon. We decided to go against the conventional wisdom and start with some easy-to-produce materials, even if they lacked the right arrangement of electrons to meet PEC criteria. Our goal was to see if a minimal 'tweaking' of the electronic arrangement in these materials would accomplish the desired results.

 

Graduate

Graduate student Chandrashekhar Pendyala studies water splitting via sunlight at UofL's Conn Center.

 

The material may be reused indefinitely as it functions as a catalyst in the PEC reaction and is not consumed. The researchers are working on the production of the alloy and would test its ability to convert solar energy to hydrogen, the report says.