Research funded by the U.S. Department of Energy has demonstrated how to tweak an inexpensive semiconductor material to generate hydrogen from water by using sunlight, a finding that could revolutionize the energy sector.
Scientists say hydrogen can be a crucial component in the transition to cleaner energy sources, but unlocking it from other compounds is the key as it is not abundantly available in a pure form on Earth.
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 finding shows that an alloy formed by a two percent substitution of antimony (Sb) in gallium nitride (GaN) has the right electrical properties to enable solar energy to split water molecules into hydrogen and oxygen. When the alloy is immersed in water and exposed to sunlight, the chemical bond between the hydrogen and oxygen molecules in water is broken. The hydrogen can then be collected, reported the Science Daily.
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.
Previous research on PEC [photoelectrochemical] has focused on complex materials, said Professor Madhu Menon of the University of Kentucky. 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.
According to the Science Daily, 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 researchers are working on the production of the alloy and would test its ability to convert solar energy to hydrogen, the report says.
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.