New efficient materials for solar fuel cells developed

Scientists, including one of Indian origin, have developed new high-performing materials for cells that harness sunlight to split carbon dioxide and water into "green fuels" like methanol and hydrogen gas, that can power cars or store energy in batteries.
"Technologies that simultaneously permit us to remove greenhouse gases like carbon dioxide while harnessing and storing the energy of sunlight as fuel are at the forefront of current research," said Krishnan Rajeshwar, a professor at University of Texas at Arlington.
"Our new material could improve the safety, efficiency and cost-effectiveness of solar fuel generation, which is not yet economically viable," Rajeshwar said.

The new hybrid platform uses ultra-long carbon nanotube networks with a homogeneous coating of copper oxide nanocrystals.
It demonstrates both the high electrical conductivity of carbon nanotubes and the photocathode qualities of copper oxide, efficiently converting light into the photocurrents needed for the photoelectrochemical reduction process.
"The performance of our hybrid has proved far superior to the properties of the individual materials," Rajeshwar said.

"These new hybrid films demonstrate five-fold higher electrical conductivity compared to their copper oxide counterparts, and generate a three-fold increase in the photocurrents needed for the reduction process," he said.
The new material also demonstrates much greater stability during long-term photoelectrolysis than pure copper oxide, which corrodes over time, forming metallic copper.

The research involved developing a multi-step electrodeposition process to ensure that a homogeneous coating of copper oxide nanoparticles were deposited on the carbon nanotube networks.
By varying the thickness of the carbon nanotube film and the amount of electrodeposited copper oxide, the researchers were able to optimise the efficiency of this new hybrid material.