According to a team of researchers at Nevada, hydrogen will be the fuel of the future. The ability to efficiently and cost-effectively produce hydrogen gas from water would transform our lives; it is a matter of finding a sustainable way to obtain it.
Imagine driving your car, powering your refrigerator, using only clean hydrogen. It's only bi-product is water. No green house gasses or smog-contributing agents are produced.
The team of researchers led my Dr. Mano Misra in the department of chemical & metallurgical engineering at Nevada are one of only a few groups of scientists' worldwide working on using sunlight and water to create clean, renewable hydrogen.
"Gasoline is only thirty percent efficient. Hydrogen is seventy percent efficient," Misra said. "We consume more oil each day than we produce."
Ideally, hydrogen is obtained by splitting the water molecule. Each water molecule has two atoms of hydrogen and one oxygen atom. A process of splitting water called electrolysis is well known, but it is energy intensive.
It requires too much electricity to make it sustainable, especially because the energy it requires usually comes from the same fossil fuels scientists are trying to replace.
Photo-catalytic water splitting, or splitting water aided by the energy of sunlight, is a hopeful alternative. Splitting a water molecule would still demand some energy input in the form of electricity, but the right combination of materials would allow sunlight to weaken the molecule enough that it would take a lot less energy to split.
This is the process of water-splitting that Misra and a team of six graduate and two research professors have been working on for the last three years thanks to a $3 million grant from the department of energy.
"I expect it will take another three to four years to make commercial," Misra said.
Although water and sunlight are both abundant, water splitting does not occur naturally because it requires a complex go-between material in the realm of "photo-catalytic semi-conductors."
In order to grasp how these photosensitive materials work, as explained my one research scientist, one can relate it to the semi-conductor materials such as those used in the common rooftops for solar energy. (Photovoltaic or PV cells.)
When a ray of sunlight strikes the material, an electron-hole pair is formed. These charge carriers are responsible for the flow of electricity in PV cells as well as being the agent in weakening the hydrogen/oxygen bond in water molecules. This is what is beginning to make hydrogen production from water-splitting a viable source of energy.
The photosensitive materials designed by Nevada scientists are self-assembled nano-structures with regular formation. (Much like the formation of a honeycomb, but where each compartment is only about 1/50th the diameter of a hair.) Because they are so small, the increased surface area creates more catalytic reactions from the sun's rays.
Right now, 10 kilograms (10 kilograms of water, 2.2 pounds.) can be converted into one kilogram of hydrogen gas, which if applied correctly could run an SUV for 75 miles. The process is too expensive yet to be sensible, but scientists are experimenting with nano-structural titanium oxide materials in combination with introducing carbon or nitrogen atoms to improve conversion efficiency.
Imagine driving your car, powering your refrigerator, using only clean hydrogen. It's only bi-product is water. No green house gasses or smog-contributing agents are produced.
The team of researchers led my Dr. Mano Misra in the department of chemical & metallurgical engineering at Nevada are one of only a few groups of scientists' worldwide working on using sunlight and water to create clean, renewable hydrogen.
"Gasoline is only thirty percent efficient. Hydrogen is seventy percent efficient," Misra said. "We consume more oil each day than we produce."
Ideally, hydrogen is obtained by splitting the water molecule. Each water molecule has two atoms of hydrogen and one oxygen atom. A process of splitting water called electrolysis is well known, but it is energy intensive.
It requires too much electricity to make it sustainable, especially because the energy it requires usually comes from the same fossil fuels scientists are trying to replace.
Photo-catalytic water splitting, or splitting water aided by the energy of sunlight, is a hopeful alternative. Splitting a water molecule would still demand some energy input in the form of electricity, but the right combination of materials would allow sunlight to weaken the molecule enough that it would take a lot less energy to split.
This is the process of water-splitting that Misra and a team of six graduate and two research professors have been working on for the last three years thanks to a $3 million grant from the department of energy.
"I expect it will take another three to four years to make commercial," Misra said.
Although water and sunlight are both abundant, water splitting does not occur naturally because it requires a complex go-between material in the realm of "photo-catalytic semi-conductors."
In order to grasp how these photosensitive materials work, as explained my one research scientist, one can relate it to the semi-conductor materials such as those used in the common rooftops for solar energy. (Photovoltaic or PV cells.)
When a ray of sunlight strikes the material, an electron-hole pair is formed. These charge carriers are responsible for the flow of electricity in PV cells as well as being the agent in weakening the hydrogen/oxygen bond in water molecules. This is what is beginning to make hydrogen production from water-splitting a viable source of energy.
The photosensitive materials designed by Nevada scientists are self-assembled nano-structures with regular formation. (Much like the formation of a honeycomb, but where each compartment is only about 1/50th the diameter of a hair.) Because they are so small, the increased surface area creates more catalytic reactions from the sun's rays.
Right now, 10 kilograms (10 kilograms of water, 2.2 pounds.) can be converted into one kilogram of hydrogen gas, which if applied correctly could run an SUV for 75 miles. The process is too expensive yet to be sensible, but scientists are experimenting with nano-structural titanium oxide materials in combination with introducing carbon or nitrogen atoms to improve conversion efficiency.
