Researchers in the Solar Materials and Electrochemistry Laboratory of Shannon Boettcher, professor of chemistry, studied the catalyst material and also developed a computer model for applying catalyst thin films in solar water-splitting devices as a tool to predict the effectiveness of a wide range of catalyst materials for solar-hydrogen production.
Boettcher's lab, located in the UO's Materials Science Institute, studies fundamental materials chemistry and physical concepts related to the conversion of solar photons (sunlight) into electrons and holes in semiconductors that can then be used to drive chemical processes such as splitting protons off water to make hydrogen and oxygen gases. Multiple labs across the country are seeking effective and economical ways of taking sunlight and directly producing hydrogen gas as an alternative sustainable fuel to replace fossil fuels.
The iron-nickel oxides, he said, have higher catalytic activity than the precious-metal-based catalytic materials that have been thought to be the best for the job.
"What we found is that when we take nickel oxide films that start out as a crystalline material with the rock-salt structure like table salt, they absorb iron impurities and spontaneously convert into materials with a layered structure during the catalysis process," Boettcher said.
Lena Trotochaud, a doctoral student and lead author on both papers, studied this process and how the films can be combined with semiconductors. "The semiconductors absorb the light, generating electron-hole pairs which move onto the catalyst material and proceed to drive the water-splitting reaction, creating fuel," Boettcher said.
The computer modeling was used to understand how the amount of sunlight that the catalyst blocks from reaching the semiconductor can be minimized while simultaneously speeding up the reaction with water to form oxygen gas. This basic discovery remains a lab accomplishment for now, but it could advance to testing in a prototype device, Boettcher added.
"We're now looking at the fundamental reasons why these materials are good," Trotochaud said. "We are trying to understand how the catalyst works by focusing on the chemistry that is happening, and then also recognizing how that fits into a real system. Our research is fundamentally guiding how you would take these catalysts and incorporate them into something that is useful for everyone in society."
This story is reprinted from material from University of Oregon, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.