Rice lab develops dual-surface graphene electrode to split water into hydrogen and oxygen
Rice University chemists have produced a catalyst based on laser-induced graphene that splits water into hydrogen on one side and oxygen on the other side. They said the inexpensive material may be a practical component in generating the hydrogen for use in future fuel cells.
The easily fabricated material developed by the Rice lab of chemist James Tour offers a robust and efficient way to store chemical energy. Tests showed the thin catalyst producing large bubbles of oxygen and hydrogen on either side simultaneously.
The process is the subject of a paper in the American Chemical Society’s Applied Materials and Interfaces.
“Hydrogen is currently made by converting natural gas to a mixture of carbon dioxide and hydrogen gas,” Tour said. “So for every two hydrogen molecules, a molecule of carbon dioxide is formed, making this traditional process a greenhouse-gas emitter.
“But if one splits water into hydrogen and oxygen, using a catalytic system and electricity generated from wind or solar energy, then the hydrogen afforded is entirely renewable,” he said. “Once used in a fuel cell, it reverts back to water with no other emissions. And fuel cells are often twice as efficient as internal combustion engines, further saving energy.”
The catalyst is another use for versatile laser-induced graphene (LIG), which Rice introduced in 2014. LIG is produced by treating the surface of a sheet of polyimide, an inexpensive plastic, with a laser. Rather than a flat sheet of hexagonal carbon atoms, LIG is a foam of graphene sheets with one edge attached to the underlying surface and chemically active edges exposed to the air.
LIG itself is inert, so turning it into a water splitter involves a few more steps. First, the lab impregnated the side of the plastic destined to pull hydrogen from water with platinum particles; then the lab used a laser to heat the surface and make LIG. The Rice material uses only a quarter of the platinum found in commercial catalysts, said Jibo Zhang, a Rice graduate student and lead author of the paper.
The other side, for oxygen evolution, was first turned into LIG and then enhanced with nickel and iron through electrochemical deposition. Both sides showed low onset potentials (the voltage needed to start a reaction) and strong performance over 1,000 cycles.
The lab came up with another variation: making the polyimide into an LIG catalyst with cobalt and phosphorus that could replace either the platinum or nickel-iron sides to produce hydrogen or oxygen. While the low-cost material benefits by eliminating expensive noble metals, it sacrifices some efficiency in hydrogen generation, Tour said.
When configured with cobalt-phosphorus for hydrogen evolution and nickel-iron for oxygen, the catalyst delivered a current density of 10 milliamps per square centimeter at 1.66 volts. It could be increased to 400 milliamps per square centimeter at 1.9 volts without degrading the material. The current density governs the rate of the chemical reaction.
Tour said enhanced LIG offers water-splitting performance that’s comparable and often better than many current systems, with an advantage in its inherent separator between oxygen and hydrogen products. He noted it may find great value as a way to chemically store energy from remote solar or wind power plants that would otherwise be lost in transmission.
The material might also serve as the basis for efficient electrocatalysis platforms for carbon dioxide or oxygen reduction, he said.
Learn more: 2 sides to this energy story
The Latest on: Water-splitting
[google_news title=”” keyword=”water-splitting” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]- Coronation Street star gives birth to her first baby – three years after finding love again after tough spliton May 10, 2024 at 12:20 am
CORONATION Street star Sair Khan has given birth to her first child. The star has played Alya Nazir in the ITV soap since 2014 and she revealed her pregnancy in December. Announcing the news ...
- New Study May Solve Mysterious Loss of Water on Venuson May 9, 2024 at 8:00 am
It's a reasonable assumption that Earth and Venus would have ended up with a similar amount of water when they formed in the same region of the solar system billions of years ago. Today, the planets ...
- DC Water repairs Northwest water main break; boil water advisory still in placeon May 9, 2024 at 7:39 am
DC Water said Thursday morning that crews repaired a water main break that prompted a boil water advisory for thousands of customers Wednesday. The advisory went into effect May 8 after DC Water found ...
- Mossyrock water system receives $265,000 in state funds for improvementson May 8, 2024 at 9:00 pm
Lewis County Water and Sewer System District No. 6, which operates around the greater Mossyrock area, has received $264,500 in state grant and loan funds to improve the system's capacity and ...
- New Study May Reveal Why Venus Has Almost No Wateron May 8, 2024 at 5:00 pm
Electrons in the atmosphere find these ions, and recombine to split the ions in two. In the process, hydrogen atoms zip away and may even escape into space entirely—robbing Venus of one of the two ...
- Venus Unveiled: The Mystery of Water Loss Revealedon May 7, 2024 at 1:40 pm
When HCO+ is split apart after combining with an electron, the now-free hydrogen atoms use the CO to catapult into space at incredible speeds, leading to Venus slowly losing its hydrogen, and ...
- Why Colorado River basin states are split on long-term plan to manage its wateron May 6, 2024 at 3:18 pm
The Upper and Lower basin states are split on a long-term plan to manage Lake Powell and Lake Mead, but meetings between the two sides are expected to pick up this month.
- Venus has almost no water: A new study may reveal whyon May 6, 2024 at 12:55 pm
Billions of years ago, Venus may have harbored as much water as Earth. Today, almost all of it has disappeared. A new study may help to explain why.
- Toward artificial leaves that float on water, bubbling fuelon May 2, 2024 at 2:14 pm
Researchers have now made such an artificial leaf device using an organic photovoltaic (OPV) material. Depending on the catalyst used, the device either splits water to make hydrogen fuel or splits ...
- As court overturns a lot-splitting law, SB 9, one early adopter asks whyon May 1, 2024 at 5:00 pm
But it requires the two lots to be split somewhat evenly ... He addressed easements, sewer lines, power lines, where water would flow when it rains, etc. Then he brought in an architect, which ...
via Google News and Bing News