Please tell us about your work

Using hydrogen for energy production is nothing new. But with his research, Materials Science and Engineering (MSE) Ph.D. candidate Ajay Pisat hopes to unlock its full potential as a primary, mainstream energy storage medium by maximizing the efficiency of hydrogen production through photocatalysis.

While there is much research being done with photocatalysis, Pisat’s work at the nano-level is an important first step leading into larger scale research, because it focuses at the lowest possible level, the structural level. He spends his time in the lab engineering the surface morphology of oxide compounds, optimizing their surface areas for hydrogen evolution which, in turn, increases the efficiency of hydrogen production through photocatalysis.

Original Link:

https://engineering.cmu.edu/news-events/news/2017/07/24-pisat-photocatalysis.html

If Pisat is able to scientifically engineer the surface structure of the oxide compound his lab uses—strontium titanate, which has a similar structure to many other oxide compounds—for maximum efficiency, then he can engineer similar compounds which absorb sunlight better. Researchers could then use these compounds at a larger scale, on entire photocatalytic systems.

“We feel that it’s the structure of the material which is vital to the process,” Pisat says. “But the chemistry of the material is vital to the actual functionality.”

How did you end up in such an offbeat, unconventional and unique career?

As a native of Mumbai, he grew up in a world that influenced his decision to pursue the research he has. “In my own lifetime,” he says, “I got to see that the climate is not the same. I have seen the quality of air degrade throughout my own childhood.” Every five years, he shares, he could see and feel the quality of the air lowering around him.

So when he entered college at IIT Madras, he was very pointed about the major he chose: materials engineering. Through his studies, he became involved with research on clean, renewable hydrogen power through photocatalysis and the material engineering of oxide compounds.

In pursuing his Ph.D. at Carnegie Mellon, he chose a program where he could study with not one, but three professors conducting nano-level research on oxide compounds used in photocatalysis: Gregory Rohrer, Paul Salvador, and Mohammad Islam. Currently, he is being co-advised by professors Rohrer and Salvador.

How does your work benefit the community?

Photocatalysis, in general, is using light in conjunction with catalyst materials to enable or quicken chemical reactions. The particular reaction involving the splitting of water into hydrogen and oxygen is called photocatalytic water splitting, or photocatalytic hydrogen production. The hydrogen produced can then be used to power on-site fuel cells or generators that are independent of infrastructure-based power grids—in other words, a consistent power source in places where those power grids don’t reach.

Two additional benefits of continued hydrogen power research are the cleanliness and renewability of the resulting hydrogen power. Unlike the carbon emissions and greenhouse gases that result from fossil fuels, hydrogen power does not yield harmful byproducts.

Taking a broad view of his research and that of others, Pisat appreciates the work that still needs to be done.

“It might not be used straightaway because everything else is just so cheap,” he says, when asked about the practical future of hydrogen power. “Coal is just so cheap. So competing with those kinds of technologies is going to take some time.”

While, as he says, it will take some time, Pisat has made great strides. “I’m definitely making a lot of progress,” he says, in terms of the results he is seeing in the lab. “Once this technique [surface morphology optimization] is perfected,” he adds, “people are going to try to use it to engineer entire photocatalytic systems to make hydrogen production completely driven by solar power. Maybe then, after five or ten years, we can see them competing with gas.”