Abstract
Analogues to thin-film solar photovoltaics (PV), a solar-fuel membrane is a flexible, integrated photoelectrochemical (PEC) device that directly converts solar energy into H2 or liquid fuels, with inputs of sunlight, water and CO2 only.  Like its PV counterpart, it is designed with inherent cost advantages, and has the potential to break the cost paradigm of panel-based PEC devices or discrete PV connected to a fuel-forming electrolyzer.  However, achieving such a flexible solar-fuel membrane is not trivial.  Modeling and simulation play an important role in enabling continuous operation of such devices, as well as improving solar-to-hydrogen efficiency. 
In this talk, I will first address materials design for splitting water into H2 and O2.  Then, I will follow up with several key experimental investigation of protective coating and solid/liquid interfaces.  Although protective coatings are not prevalent in PV research, they contribute to an emerging field of PEC research and are essential because all technologically important semiconductors so far like Si and GaAs photocorrode.  With protective coating strategies, a 10% efficient water-splitting prototype has been demonstrated.  With modeling-inspired materials design, I will show a viable pathway beyond 20% efficiencies. 
Finally, I will discuss challenges and opportunities for advancing to particle-based solar fuel reactors.  I will conclude with an outlook for basic research needs of photocatalytic processes at solid/liquid interfaces. 
 
Speaker bio:
Shu Hu is an Assistant Professor of Chemical & Environmental Engineering at Yale University.  He is also affiliated with the Energy Science Institute at Yale West Campus.  Shu Hu graduated from Tsinghua University in 2006 and received his PhD degree of Materials Science and Engineering in 2011 from Stanford University, where he worked on nanoscale germanium crystal growth and epitaxy control.  He was then a postdoctoral scholar working with Professor Nate Lewis at California Institute of Technology and Joint Center for Artificial Photosynthesis, where his work spans fundamental and applied research areas in nanophotonics, nanoscale III-V growth and solid-electrolyte interfaces for artificial photosynthesis.  Dr. Hu has 5 issued patents, and is a co-author of over 30 peer-reviewed journal articles including Science, Nature Nanotechnology, Energy & Environmental Sciences and Nano Letters.  Dr. Hu has been awarded several honors for his work including the Stanford Graduate Fellowship Award, the MRS Graduate Student Gold Award and the Ross N. Tucker Award.  The experimental demonstration of protective coatings was reported in major media including NPR News, Scientific American, CE&N News, Nature, and highlighted in the US Department of Energy BES program report.