Artificial photosynthesis technology that directly converts solar energy into hydrogen has entered the commercialization stage.
A team of professors Lee Jae-sung, Seok Sang-il, and Jang Ji-wook from the Department of Energy and Chemical Engineering at Ulsan National Institute of Science and Technology (UNIST) announced on the 23rd that they have developed a 'modular artificial leaf' with high efficiency, durability, and scalability. The research results were published in the international journal Nature Communications in May.
The artificial leaf is a concept that produces hydrogen using only sunlight and water, similar to natural leaves without any additional power source. Although it is a technology with excellent efficiency and economic viability, the efficiency level required for commercialization has not yet been achieved. To be commercially viable, the solar-to-hydrogen efficiency (Solar to Hydrogen Efficiency, STH) must exceed 10%, and this efficiency should also be achieved not just as individual units but as a modular unit.
The UNIST research team fabricated a high-efficiency photoanode using a perovskite-based solar absorption layer and nickel-iron-cobalt catalyst, developing a modular artificial leaf expanded into a 4×4 array. They improved efficiency and stability by combining a chlorine-added perovskite absorption layer, a UV-resistant electron transport layer, and a catalyst layer. To prevent damage from moisture exposure to the electrodes, they applied special nickel foil and resin bag technology, allowing for retention of 99% of the initial performance even after 140 hours of continuous operation.
The artificial leaf module produced achieved a solar-to-hydrogen conversion efficiency of 11.2%. This marks the highest level reported among artificial leaves so far, and it is significant that it achieved the required efficiency of over 10% at the modular level for commercialization.
Professor Lee Jae-sung noted, "This achievement is significant in that it exceeds merely high-efficiency hydrogen production in the laboratory and has achieved the commercialization benchmark of efficiency over 10% at a usable level for modular artificial photosynthesis devices. Additionally, it can be scaled up to large-area artificial leaf panels like solar panels, making a decisive advance towards commercialization."
References
Nature Communications (2025), DOI : https://doi.org/10.1038/s41467-025-59597-2