New coating is a breakthrough for hydrogen fuel Photocatalysis using particles in water is a promisi

New coating is a breakthrough for hydrogen fuel

Photocatalysis using particles in water is a promising technology for generating fuels from sunlight. One major obstacle to producing these solar fuels cheaply and abundantly, though, is that it requires semiconductors that are efficient but prone to corrosion.

In a breakthrough that overcomes this challenge, the lab of Shu Hu, assistant professor of Chemical & Environmental Engineering, has found a solution with a first-of-its-kind coating. The results are published in the Proceedings of the National Academy of Sciences.

Water-splitting systems—which break water down to hydrogen and oxygen—need semiconductor materials with narrow bandgaps (a property allowing for absorbing more sunlight), which efficiently converts solar energy to chemical energy. While these materials can easily capture sunlight, they all corrode under illumination via self-reduction or self-oxidation. It’s a challenge that researchers have spent more than a half-century trying to solve. Strategies to protect these materials tend to limit their abilities to separate the charges of negative electrons and positive holes, a process that is essential to photocatalysis but harder to achieve than it is for other systems, such as solar cells. Typically, layers designed to guard these systems protect only one of the system’s two electrodes, namely the cathode or anode, limiting it to allow for the transport of either electron or hole—but not both.

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