By smoothening the surface of hematite, a team of researchers led by Boston College chemist Dunwei Wang achieved ‘unassisted’ water splitting using the abundant rust like mineral and silicon to capture and store solar energy within hydrogen gas. Finding an efficient solar water splitting method to mine electron rich hydrogen for clean power has been thwarted by the poor performance of hematite. But by ‘regrowing’ the mineral’s surface, a smoother version of hematite doubled electrical yield, opening a new door to energy harvesting artificial photosynthesis, according to a report published in the journal Nature Communications.
Regrown hematite proved to be a better power generating anode, producing a record low turn on voltage that enabled the researchers to be the first to use earth abundant hematite and silicon as the sole light absorbers in artificial photosynthesis, said Boston College associate professor of chemistry Dunwei Wang, a lead author of the report. The new hydrogen harvesting process achieved an overall efficiency of 0.91 percent, a ‘modest’ mark in and of itself, but the first ‘meaningful efficiency ever measured by hematite and amorphous silicon, two of the most abundant elements on Earth,’ the team reported. ‘This offers new hope that efficient and inexpensive solar fuel production by readily available natural resources is within reach,’ said Wang.