Shu Hu Joins Yale Engineering Faculty

Of all the major challenges facing the modern world, discovering effective and sustainable alternative energy sources is one of the most critical. Shu Hu, who recently joined the Yale faculty as an assistant professor in the Department of Chemical & Environmental Engineering, is taking a novel approach to find a solution.

Widely considered the "power source of the future," solar energy stored as chemical energy in its densest form – chemical fuels – can theoretically provide a sustainable future for society. To that end, Hu designs photosynthetic electrochemical devices that actively "split" water into hydrogen fuels and oxygen under sunlight, the most abundant renewable energy source. Thanks largely to his innovations, scientists can stably produce hydrogen fuels from the sun with more than 10% solar-to-fuel conversion efficiencies and store solar energy acquired from a hot summer day into densified fuels. These stored fuels can then eventually be applied on a cold winter day.

A challenge for the past 50 years, materials used for solar fuel applications are commonly subject to photocorrosion and degradation, which diminish efficiency to zero over a few hours. Extending from the field of electronic materials which enabled computer chips, Hu has discovered that applying the Atomic-Layer Deposition technique to coat the otherwise unstable materials can dramatically extend the stability of the materials from time scales of hundreds of hours to over 2,200 hours and beyond.

This recent breakthrough has proven to be a practical pathway toward making an efficient and stable chemical device previously not possible. It brings back an entire class of materials that are otherwise unstable for solar fuels but are ubiquitously used for solar photovoltaic panels. Hu also develops computer modeling for solar fuel which couples processes of light absorption, photo-catalysis, product transport, and separation with much of the same intention as engineers designing chemical reactors.

Through photosynthesis, plants convert solar energy to fuel. At the Energy Sciences Institute on Yale's West Campus, faculty from multiple disciplines are collaborating to understand how photosynthesis works and mimic it for artificial photosynthesis. Given Hu's experience in device design and implementation, it should come as no surprise that he is a natural fit as a new, key member of the Institute.

"My vision is that, by learning what nature does best and modeling the key processes, we can then create new solar chemical devices beyond the conventional paradigm and achieve high-efficiency and long-term stability at a low cost," says Hu. "This would change the way we utilize solar energy. While solar panels intermittently output electrical energy, these next generation solar devices will consistently output chemical energy whenever there is sunshine!"