Sugar has been a part of life for at least 10,000 years. It is a natural sweetener found in all plants and has many applications. It is commonly used to sweeten food and preserve food from spoilage and has also been used for medicinal purposes, often masking the bitterness of medicines. Some people might not know that sugar is hiding remarkable energy potential that Korean researchers have already begun to unlock. We are not referring to its good energy source for humans via consumption, but its promise as a renewable energy source.
Sugar is hiding energy potential that could power the world
Did you know that sugar could produce hydrogen? A research team led by Professors Seungho Cho and Kwanyong Seo from the School of Energy and Chemical Engineering at UNIST, in partnership with Professor Ji-Wook Jang’s team from the Department of Materials Science and Engineering at UNIST, discovered a pioneering system for hydrogen production.
Why is hydrogen significant? It is a next-generation fuel since it does not emit greenhouse gases while burning and stores energy at a density 2.7 times greater than gasoline. However, most of the world’s produced hydrogen is procured from natural gas, which results in high carbon dioxide emissions.
The pioneering system uses biomass procured from sugarcane waste and silicon photoelectrodes to produce hydrogen using solar power, resulting in a production rate that is four times higher than the US Department of Energy’s commercialization benchmark.
Korea has developed a method for extracting this energy
The research team’s system oxidizes furfural at the copper electrode to produce a high-value product. The residual matter converts into furoic acid, a product of high value. Water also splits at the silicon photoelectrode, resulting in hydrogen. This leads to a coproduction mechanism that theoretically doubles the production rate compared to traditional PEC systems. The mechanism’s performance obtains 1.4 mmol/cm²·h, almost four times the benchmark of 0.36 mmol/cm²·h.
The photoelectrode uses sunlight and produces electrons, which initiate the hydrogen production. The team utilizes crystalline silicon photoelectrodes in the coproduction mechanism as they yield many electrons. Of course, no system is without its challenges. A low voltage of 0.6V is produced, making the start of hydrogen production difficult due to the absence of external power.
Overcoming the challenges of extracting sugar’s energy potential
The research team kept an open mind and managed to address the issue. They added an oxidation reaction of furfural on the opposite electrode to balance the voltage, simultaneously preserving the crystalline silicon photoelectrodes’ high photocurrent density and reducing the system’s voltage burden. This allowed hydrogen production without external power.
The team’s system also uses an interdigitated back contact (IBC) structure to reduce voltage losses within the photoelectrode. The electrode is wrapped in nickel foil and glass layers, protecting it from electrolytes to ensure long-term stability. The overflow structure of the silicon photoelectrode supplies a self-cooling effect, resulting in high efficiency and stability compared to external coupling structures.
“This technology achieves an H₂ production rate from solar energy that is four times higher than the commercialization standard set by the U.S. Department of Energy, playing a crucial role in enhancing the economic viability of solar H₂ and ensuring competitive pricing against fossil fuel-based H₂.” – Professor Jang.
According to the team’s scientific paper, it could satisfy a considerable portion of the hydrogen production demand in the long term. The highly efficient system maximizes the high photocurrent of c-Si and represents significant progress toward practical solar-to-hydrogen production in real-world applications. If they continue to develop their system for real-world applications, sugar will surely become even more famous and perhaps high in demand. Only time will tell what all of this holds for the future.
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