Researchers at Rice University Engineering School in Houston have developed a new efficient and low-cost device that splits water to generate hydrogen fuel.
The platform combines perovskite solar cells and catalytic electrodes that generate electricity when activated by sunlight. When the currents flow toward the catalysts, they split the water into oxygen and hydrogen as high as 6.7%.
Although this type of catalysis is very common, the researchers integrated the electrodes and a layer of petrovskite into one single module. This module generates hydrogen with no further input when it’s immersed in water and places in the sunlight. Furthermore, the design if this self-sustaining synthesizer can be easily mass-produced.
The platform was launched by Jun Lou, lead author and Rice postdoctoral fellow Jia Liang; together with their collaborators in the American Chemical Society journal ACS Nano.
Perovskites are crystals that have cube-like lattices with the ability to tap light. To date, the most efficient perovskite solar cells realize an efficiency of more than 25%; but the materials are costly and get stressed by heat, humidity, and light.
Liang explained that the perovskite may not be the main component, but rather the polymer surrounding it. This safeguards the module and enables it to be submerged for longer periods. “Jia has replaced the more expensive components, like platinum, in perovskite solar cells with alternatives like carbon.”
The researches added that the integrated devices are promising because they create a system that is sustainable. It does not require any external power to keep the module running.
“Others have developed catalytic systems that connect the solar cell outside the water to immersed electrodes with a wire. We simplify the system by encapsulating the perovskite layer with a Surlyn (polymer) film,” Lou said.
The patterned film enables sunlight to reach the solar cell while safeguarding it. At the same time, it acts as an insulator between the electrodes and the cells.
“With a clever system design, you can potentially make a self-sustaining loop. Even when there’s no sunlight, you can use stored energy in the form of chemical fuel. You can put the hydrogen and oxygen products in separate tanks and incorporate another module like a fuel cell to turn those fuels back into electricity,” they explained.
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