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
- Highly efficient hydrogen gas production using sunlight, water and hematiteon May 7, 2020 at 10:10 am
A research group led by Associate Professor Tachikawa Takashi of Kobe University's Molecular Photoscience Research Center has succeeded in developing a strategy that greatly increases the amount of ...
- Figure 1: Mesocrystal Photoanode Formation and Photochemical Water Splitting Characteristics (image)on May 7, 2020 at 7:27 am
The oxidation potential is 1.23V. The solar water splitting capacity was greatly enhanced by making the nano-particles in the mesocrystal structures smaller.
- Water-Splitting Module a Source of Perpetual Energyon May 5, 2020 at 10:35 am
HOUSTON, TX — May 4, 2020 — Rice University researchers have created an efficient, low-cost device that splits water to produce hydrogen fuel. The platform developed by the Brown School of Engineering ...
- Water-Splitting “Artificial Leaf” Module a Source of Perpetual Energyon May 4, 2020 at 10:01 pm
Artificial leaf' concept inspires Rice University research into solar-powered fuel production. Rice University researchers have created an efficient, low-cost device that splits water to produce ...
- Water-splitting module a source of perpetual energyon May 4, 2020 at 10:42 am
lead author and Rice postdoctoral fellow Jia Liang and their colleagues in the American Chemical Society journal ACS Nano ("A Low-Cost and High-Efficiency Integrated Device toward Solar-Driven Water ...
- Water-splitting module a source of perpetual energyon May 4, 2020 at 9:45 am
Rice University researchers have integrated high-efficiency solar cells and electrode catalysts into an efficient, low-cost device that splits water to produce hydrogen fuel.
- Tuning of oxygen vacancy-induced electrical conductivity in Ti-doped hematite films and its impact on photoelectrochemical water splittingon May 4, 2020 at 2:04 am
Amongst existing technologies, hydrogen evolution by photocatalytic dissociation of ubiquitous water in a photoelectrochemical cell (PEC) is one of the simple processes to convert solar energy into a ...
- Water-splitting module a source of perpetual energyon May 3, 2020 at 5:00 pm
Rice University. (2020, May 4). Water-splitting module a source of perpetual energy: 'Artificial leaf' concept inspires research into solar-powered fuel production. ScienceDaily. Retrieved May 4 ...
- Visible light-photocatalytic water-splitting for hydrogenation of aryl chlorideson April 29, 2020 at 8:48 pm
Recently, Chenliang Su's research group from Shenzhen University, China, proposed a photocatalytic water splitting technology to in-situ "bubble" H 2 for controllable hydrogenation of aryl chlorides, ...
- photoelectrochemical water splittingon December 19, 2019 at 6:07 pm
We are first in your inbox with the most important news in the industry―keeping you smarter and one-step ahead in this ever-changing and competitive market.
via Google News and Bing News