Can Gold, Sunlight, and Water Make Hydrogen Fuel?
Charleston native and West Virginia University graduate student Scott Cushing is in pursuit of one of the holy grails of energy sourcing: instead of using gasoline, or other fossil fuels with harmful emissions, he aims to use water and the sun to harvest hydrogen gas.
Cushing explains that his goal is ultimately to figure out a way to split water and efficiently harvest hydrogen gas—a fuel that could be used to power automobiles like the zero-emission, mid-size, four-door sedan Toyota just announced is in the works for this year.
“We’re very interested in how you can take sunlight and create a fuel with it. And specifically we want to do that by splitting water into hydrogen. If we can do that, then it’s a resource that’s always there.”
Cushing is deep into research at the nano level working with what are called Plasmons.
“Plasmonics?” Cushing says, “It’s a fancy scientific word to basically describe the fact that we’re making really, really small antennas out of gold.”
So he takes a piece of gold that is smaller than a wavelength of light and uses it as an antenna to harvest and somehow amplify the energy from the sun. He says using noble metals like gold and silver in this way isn’t new, nor is using a semiconductor like those found in solar panels as a way to convert solar energy into a usable fuel.
However on their own, each of these systems lacks key properties to allow high efficiency solar-to-hydrogen conversion, which would conceivably allow us to fill tanks in our back yards with hydrogen for our own personal use.
“So our work went into finding a way to actually couple these together. That’s where these advanced lasers and all of these optics come into play.”
Cushing stands next to a giant floating table—so sensitive that it needs a cushion of air to protect it from the vibrations of the building. And what’s on top of the table? A laser maze. About fifty mirrors and dozens of lenses to control the path-length and manipulate the laser beam. Cushing says that even with the special table, when the temperature changes dramatically outside, sometimes he needs to realign lenses and mirrors.
Cushing explains that there’s a lot of information packed into the journey light takes through space and time. And understanding or observing that information with our limited human perspectives requires some creative maneuvering.
He compares his lasers (there are actually two on the table) to racers, explaining that timing them through this maze of obstacles reveals certain information about how light reacts to the materials they encounter enroute.
“If one comes out earlier,” Cushing says, “he may have seen something completely different than the guy who came out ten minutes later. They come out at the same time and they probably are gonna see around the same experience.”
Cushing says the research is at a point where results are impressive, but it could still be years before a significant breakthrough will make collecting hydrogen gas efficient and marketable.
“We’re getting to the point now where I can take you to the other lab and we can put this magic-looking material in water, shine light on it, and you’ll see [hydrogen] bubbles come off of it. But obviously, there are a lot of steps between that and having an entire field of hydrogen generators in your back yard.”
“It’s like the computer,” Cushing adds. “They made the transistor, and then everyone could start working on it.”
Cushing’s work is funded by the National Science Foundation. The research project is headed by Dr. Nick Wu with Dr. Alan Bristow as a collaborator, both professors act as Cushing’s advisor in pursuing his graduate degree.