Solar energy appears to be the only form of renewable that can be exploited at level that matches the world’s growing needs.
Solar energy appears to be the only form of renewable that can be exploited at level that matches the world’s growing needs. However, it is equally necessary to find efficient ways to store solar energy in order to ensure a consistent energy supply when sunlight is scarce. One of the most efficient ways to achieve this is to use solar energy to split water into hydrogen and oxygen, and get the energy back by consuming hydrogen in a fuel cell. But collecting solar energy on a large and sustainable scale means that such cells must be made from materials that are cheap, abundant, and have 10% solar to hydrogen conversion efficiency. Publishing in Nature Communications, an EPFL-led team of scientists has found a method to create a high-efficiency, scalable solar water splitting device using cheap materials.
Although one of the best means of sourcing renewable energy, solar systems cannot consistently produce adequate energy since sunlight varies from time to time and place to place. A solution to this problem is a device that can store energy in the form of hydrogen for later use, offering a consistent output over time with very little pollution.
One of the most sustainable methods of producing hydrogen is photoelectrochemical (PEC) water-splitting. Solar energy is used to break water molecules into hydrogen and oxygen through a process called “hydrogen evolution reaction”. This reaction requires a catalyst, which is a chemical agent that increases its speed. In PEC water-splitting devices, a common catalyst used to split water is platinum, which is deposited on the surface of the solar panel’s photocathode – the solar panel’s electrode that converts light into electric current.
A research team at EPFL has now found a way to make efficient solar-powered water splitting devices using abundant and cheap materials. The group of Xile Hu developed a molybdenum-sulfide catalyst for the hydrogen evolution reaction, and the group of Michael Grätzel developed copper oxide as a photocathode. The researchers found that the molybdenum sulfide can be deposited on the copper oxide photocathode for use in PEC water splitting through a simple deposition process that can be easily expanded onto a large scale.
The technique shows comparable efficiency to other hydrogen evolution reaction catalysts like platinum, it preserves the optical transparency for the light-harvesting surface and it shows improved stability under acidic conditions, which could translate into lower maintenance. But more importantly, both the catalyst and the photocathode are made with cheap, earth-abundant materials that could greatly reduce the cost of PEC water-splitting devices in the future. According to senior author Xile Hu, the work represents a state-of-the-art example for solar hydrogen production devices.
The Latest on: Water-splitting
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The Latest on: Water-splitting
- Co/Cu2O assisted growth of graphene oxide on carbon nanotubes and its water splitting activitieson April 22, 2021 at 8:27 pm
A hybrid nanomaterial of Co/Cu2O based on carbon nanotubes (CNTs) is proposed as a highly promising photocatalyst for solar hydrogen production. Cu2O nanoparticles are active catalysts for hydrogen ...
- Study may Help Develop Ideal Photoelectrode for Solar Water Splittingon April 20, 2021 at 6:57 am
Metal oxides, including rust, are fascinating photoelectrode materials that are used for producing green hydrogen with solar light.
- Extraction of mobile charge carrier photogeneration yield spectrum of ultrathin-film metal oxide photoanodes for solar water splittingon April 18, 2021 at 5:00 pm
Although the photogeneration yield spectrum is a key property for photoabsorbers in photovoltaic and photoelectrochemical cells, its characterization remains challenging. An empirical method to ...
- Potential-dependent switch aids water-splitting using cobalt-oxide catalystson April 14, 2021 at 8:00 am
Using abundant cobalt and a unique experimental approach to probe ways to speed a sluggish catalytic reaction to harvest hydrogen from water, researchers from Boston College and Yale University ...
- A nucleus-coupled electron transfer mechanism for TiO2-catalyzed water splittingon April 9, 2021 at 3:38 pm
Based on first-principles calculations, we reveal that in the photocatalytic oxygen evolution reaction (OER) at the TiO2/water interface, the formation of an O–O bond always involves the anti-bonding ...
- Controlling bubble formation on electrodeson March 29, 2021 at 12:23 am
Study finds the wettability of porous electrode surfaces is key to making efficient water-splitting or carbon-capturing systems. Using electricity to split water into hydrogen and oxygen can be an ...
- Controlling bubble formation on electrodeson March 27, 2021 at 6:49 pm
A new study finds the wettability of porous electrode surfaces is key to making efficient water-splitting or carbon-capturing systems. Using electricity to split water into hydrogen and oxygen can ...
- Controlling bubble formation on electrodeson March 26, 2021 at 1:57 pm
But as water-splitting technologies improve, often using porous electrode materials to provide greater surface areas for electrochemical reactions, their efficiency is often limited by the formation ...
- Potato Chips Inspire Novel Method for Water-Splittingon March 26, 2021 at 11:50 am
Potato chips. Led by Abraham Harris Professor of Materials Science and Engineering Vinayak Dravid, researchers in his VPD Group developed a new material to synthesize electrodes suitable for ...
- Harvard Researchers Develop Cheaper Method For Renewable Energy Storageon March 25, 2021 at 9:52 pm
The article, titled “Continuous electrochemical water splitting from natural water sources via forward osmosis,” was published in the journal Proceedings of the National Academy of Sciences on ...
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