Chemists at the University of Texas at Arlington (UTA) have developed new high-performing materials that can use sunlight to split carbon dioxide and water into usable fuels like methanol and hydrogen gas. These ‘green fuels’ could be used to power cars and home appliances, 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, UTA distinguished professor of chemistry and biochemistry and co-founder of UTA's Center of Renewable Energy, Science and Technology. "Our new material could improve the safety, efficiency and cost-effectiveness of solar fuel generation, which is not yet economically viable."

The new hybrid platform uses networks of ultra-long carbon nanotubes with a homogeneous coating of copper oxide nanocrystals. The material benefits from 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. It is described in a paper in the Journal of Materials Chemistry.

Morteza Khaledi, dean of the UTA College of Science, said Rajeshwar's work demonstrates the university's commitment to addressing critical issues with global environmental impact under the Strategic Plan 2020. "Dr. Rajeshwar's ongoing global leadership in research focused on solar fuel generation forms part of UTA's increasing focus on renewable and sustainable energy," Khaledi said. "Creating inexpensive ways to generate fuel from an unwanted gas like carbon dioxide would be an enormous step forward for us all."

"The performance of our hybrid has proved far superior to the properties of the individual materials. 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."Krishnan Rajeshwar, UTA

For this solar fuel cells project, Rajeshwar worked with Csaba Janáky, an assistant chemistry professor at the University of Szeged in Hungary and Janáky's master's student Egon Kecsenovity. Janaky served as a UTA Marie Curie Fellow from 2011 to 2013.

"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." 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 the formation of a homogeneous coating of copper oxide nanoparticles 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 optimize the efficiency of this new hybrid material.

This story is adapted from material from the University of Texas at Arlington, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.