Hydrogen has emerged as a popular green alternative to fossil fuel resources due to its carbon-neutral combustion products (water, electricity and heat) and is considered the next generation fuel for a zero-emission society. I’m here. Ironically, however, the main source of hydrogen is fossil fuels.

One way to produce hydrogen in a clean and sustainable way is by solar water splitting. This process, known as ‘photoelectrochemical (PEC) water splitting’, is the basis for the operation of organic solar cells. The advantages of this method are 1) mass production of hydrogen in a limited space without using a grid system, and 2) high efficiency conversion of solar energy to hydrogen. However, despite such advantages, the photoactive materials used in conventional PECs do not possess the necessary properties for commercial settings. In this regard, organic semiconductors (OS) have emerged as potential photoelectrode materials for commercial PEC hydrogen production due to their high performance and low cost printing. However, the drawback is that OS has poor chemical stability and low photocurrent density.

Now, a research team led by Professor Sanghan Lee at Gwangju University of Science and Technology in South Korea may have finally solved the problem. In a recent breakthrough that appeared on the cover of Journal of Materials Chemistry A, the team took an approach based on encapsulating his OS photocathode in platinum-decorated titanium foil. Exposure to electrolyte.

“Metal foil encapsulation prevents electrolyte penetration into the OS and helps improve long-term stability, as demonstrated in previous studies and other reports on OS, making it a long-term It is a powerful approach for achieving stable OS-based photocathode-based photoelectrodes,” explains Professor Lee. This study was made available online on May 14, 2022 and was published in Issue 25 of the journal on July 7, 2022.

The team fabricated an organic solar cell in which the OS photocathode was covered with a titanium foil and well-dispersed platinum nanoparticles. As a result of the tests, the OS photocathode showed an onset potential of 1 V and a photocurrent density of -12.3 mA cm against the reversible hydrogen electrode (RHE).^-2 at 0V_RHEMost notably, this cell exhibited record operational stability, sustaining 95.4% of the maximum photocurrent for over 30 hours without any noticeable degradation in OS. Additionally, the team was able to test the module under real sunlight and produce hydrogen.

The highly stable and efficient PEC modules developed in this study can enable large-scale production of hydrogen and inspire innovative routes for building future hydrogen gas stations. “With the growing threat of global warming, it is imperative to develop environmentally friendly energy sources. We can,” speculates an optimistic Professor Lee.

We hope his vision comes true soon!

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reference

DOIs: https://doi.org/10.1039/d2ta02322a

Author: Seo Se-hoon^ab Jeonghoon Lee^{Alternating current} Kim Ye Joon^a Kim Seung Gyu,^a Chang Jae Yoon,^d Hojun Choi,^a Sanson Lee^Ade Lee Kwan Hee ^Ade Kim Hee Joo ^F and Sanghan Lee ^*a

Affiliation:

^a College of Materials Science and Engineering, Gwangju University of Science and Technology

^b Lawrence Berkeley National Laboratory, Chemical Science Division and Liquid Sunlight Alliance

^c Department of Chemistry and Biomolecular Engineering, University of Illinois at Urbana-Champaign

^d Institute of Solar Energy and Sustainable Energy, Gwangju University of Science and Technology

^e Higer Leading Material Center, Gwangju University of Science and Technology

^What Energy Convergence Graduate School, Integrated Technology Institute, Gwangju University of Science and Technology

About Gwangju Institute of Science and Technology (GIST)

Gwangju Institute of Science and Technology (GIST) is a research-oriented university in Gwangju, South Korea. Established in 1993, his GIST has become one of the most prestigious schools in South Korea. The university aims to create a strong research environment to spur scientific and technological progress and foster collaboration between international and national research programs. With the motto “Proud Creator of Future Science and Technology”, GIST consistently wins his one of the best university rankings in South Korea.

Website: https://www.gist.ac.kr/

About the author

Dr. Sanghan Lee is a professor at the School of Materials Science and Engineering at the Gwangju Institute of Science & Technology (GIST) in South Korea. Before coming to GIST, he completed his Ph.D. After receiving a doctorate in materials engineering from the University of Wisconsin-Madison, he worked as a postdoctoral researcher at the same university. His group at GIST is currently developing thin films based on various semiconductor materials for the fabrication of high-performance photoelectrodes, memory his devices, and gas sensors.