Resnick Institute


Is Water the Ideal Semiconductor for Direct Solar-Cell-Driven Desalination?

One in ten human beings does not have access to clean potable water, a number that the United Nations predicts will more than quadruple in the next 13 years mostly due to population growth in developing nations. While oceans constitute an enormous supply of water, the concentrated salt present in sea water is poisonous to people. Therefore, there exists an urgent need for rapidly-deployable, reliable, affordable, and efficient technologies to desalinate salt water for human consumption and agriculture.

My group is pioneering a new solar-energy-conversion technology that we think can help supply potable water to those people that need it most. Central to our approach is an innovative mechanism for light-to-ionic energy conversion inspired by traditional inorganic solar cells and photosynthesis in Archaea and that uses water as the semiconductor. We have shown that in one polymeric material the energy in sunlight is directly converted into ionic power, a process that theoretically can desalinate ocean water 20 times more rapidly than state-of-the-art solar thermal distillation can.

Our enabling materials breakthrough utilized covalent photoacid-dye-modified ion-exchange membranes. Absorption of visible light by photoacid molecules decreased their pKa values, which resulted in liberation of protons that were then collected at membranes selective to specific ionic charges. The resulting ionic photocurrent and photovoltage were consistent with a mechanism where ions were pumped against a concentration gradient to produce power. It is our hope that a technology based on our research can help overcome some of the urgent global challenges surrounding clean water scarcity.

About Shane

Shane obtained a BS in mathematics, with a minor in computer programming, from Towson University and subsequently worked as a software engineer, community college instructor, and high school teacher prior to attending graduate school. Shane obtained an MS in nutrition from the University of Maryland, College Park followed by MA and PhD degrees in photo-physical inorganic chemistry from the Johns Hopkins University, where he worked for Prof. Jerry Meyer. He then worked for Prof. Nate Lewis as a DOE-EERE Postdoctoral Research Awardee at the California Institute of Technology until 2013.

Since that time, Shane has been an Assistant Professor at the University of California, Irvine in the Department of Chemistry and holds a joint appointment in the Department of Chemical Engineering and Materials Science. His research interests are driven by the pursuit of understanding and controlling energy conversion mechanisms for applications in solar fuels devices, photovoltaics, solar seawater desalination, fuel cells, and redox flow batteries.

Shane was recently named one of five inaugural Moore Inventor Fellows, is a recipient of a Beall Innovation Award, and was named a Sloan Research Fellow and a Cottrell Scholar. His research group is also supported by funding from the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy and the U.S. National Science Foundation’s Chemical Catalysis Program.