Quantum materials could enable the solar-powered production of hydrogen from water - Energy & Green Tech - Hi Tech & Innovation

Structural characterizations of InGaN/GaN SLs. Credit: Pan et al. (Nature Energy, 2026).

Hydrogen fuel is a promising alternative to fossil fuels that only emits water vapor when used and could thus help to lower greenhouse gas emissions on Earth. In the future, it could potentially be used to fuel heavy-duty transport vehicles, such as trucks, trains, and ships, as well as industrial heating and decentralized power generation systems.

Unfortunately, most current methods to produce hydrogen rely on the burning of fossil fuels, which limits its environmental advantages. Given its potential, many energy engineers worldwide have been trying to devise more sustainable strategies to produce hydrogen on a large scale.

One proposed method for the clean production of hydrogen is known as photocatalytic water splitting. This approach entails splitting water molecules into hydrogen and oxygen, using photocatalysts (i.e., materials that respond to sunlight and prompt desired chemical reactions).

Researchers at University of Michigan recently developed new excitonic quantum superlattices, ultra-thin layered superconducting materials in which pairs of bound electrons and holes (i.e., excitons) form, that could support the solar-powered production of hydrogen. These promising materials, presented in a paper published in Nature Energy, were found to split water and produce clean hydrogen with a remarkable efficiency. 

The dynamic process of gas production for outdoor test in filter view (green). Credit: Nature Energy (2026). DOI: 10.1038/s41560-026-01972-4 (for short film clip, see link below)

"Producing clean hydrogen directly from sunlight and water has emerged as a promising path for achieving carbon neutrality and environmental sustainability," wrote Yuyang Pan, Bingxing Zhang, and their colleagues in their paper.

"However, the inefficient utilization of photogenerated charge carriers in photocatalysts hinders the solar-to-hydrogen efficiency. We show the use of excitonic quantum superlattice structures, consisting of nanometer-scale gallium nitride and indium gallium nitride, to achieve effective charge steering for photocatalytic overall water splitting."

An innovative quantum superlattice design

Pan, Zhang, and their colleagues designed new layered materials that combine the semiconductors gallium nitride and indium gallium nitride into a so-called "superlattice." This is a periodic and nanometer-scale stack of two materials, which exhibits specific optoelectronic properties.

"With this structure, the lifetime of photogenerated indirect excitons, composed of electrons and holes via Coulomb interaction, can be substantially prolonged by exploiting the quantum-confined Stark effect," wrote Pan, Zhang, and their colleagues.

"As a result, photogenerated carriers can be effectively utilized for surface reactions, achieving high external quantum efficiency extended to visible light and a solar-to-hydrogen efficiency of 3.16% under ambient conditions and concentrated sunlight. Furthermore, outdoor scale-up demonstration achieved an average solar-to-hydrogen efficiency of 1.64% under 204-fold sunlight intensity."

Leveraging a phenomenon known as the quantum-confined Stark effect, the researchers were able to extend the lifetime of excitons within their carefully engineered quantum superlattices. They then tested the performance of the materials for prompting the splitting of water into hydrogen and oxygen via solar energy.

Scale-up and outdoor application demonstration. Credit: Nature Energy (2026). DOI: 10.1038/s41560-026-01972-4

Next steps and real-world applications

In initial laboratory and outdoor field experiments, the researchers found that their quantum materials enabled the solar-powered conversion of water into hydrogen with an efficiency of 3.16% in the lab under concentrated sunlight and up to 1.64% in an outdoor setting. These results are encouraging and highlight the potential of quantum materials for the realization of photocatalytic water splitting.

While the efficiencies reported by Pan, Zhang, and their colleagues are still far lower than they should be to enable the widespread adoption of water splitting systems, they prove the viability of converting water into hydrogen leveraging quantum superlattices. In the future, the materials introduced by the researchers could be improved further and could inspire the design of other similar superlattices.

Eventually, this could open new possibilities for the clean production of hydrogen on a large scale, contributing to global efforts aimed at reducing greenhouse gas emissions. 

by Ingrid Fadelli, Phys.org

edited by Gaby Clark, reviewed by Robert Egan 

Source: Quantum materials could enable the solar-powered production of hydrogen from water