Introduction

This is a very exciting time to be working in the field of energy conversion, an area that is poised to undergo a massive transformation in the coming years as society strives to achieve a more sustainable energy future. In the Solar Fuels Engineering Lab, our research is strongly motivated by the need to accelerate this transformation through the development of solar, catalytic, and electrochemical technologies that will form the backbone of this future energy system. We are also deeply interested in the fundamental chemistry and physics that underlies these technologies, as we seek to use that knowledge in concert with innovative device- and systems- level engineering to make those technologies more efficient, durable, scalable, and economically viable.

Of particular interest in our research group are photoelectrochemical (PEC) and photovoltaic (PV) electrolysis reactors, electrochemical devices that are capable of converting sunlight into storable chemical energy, or “solar fuels”, such as hydrogen. The fields of PEC and electrochemical energy conversion have tremendous potential to transform how renewable energy is captured and stored because they offer a means to overcome a primary weakness of solar energy: its intermittency. By converting sunlight into solar fuels during the day, PEC and PV electrolysis technologies enable energy from the sun to be stored in the form of chemical bonds during the day and converted back to electricity with a fuel cell when the sun is not shining. Shown here are schematics of solar fuels production pathways based on PV-electrolysis and photoelectrochemical cells:

Figure: Two pathways for the conversion of solar energy into solar fuels such as hydrogen.

In photovoltaic electrolysis (PV-electrolysis), conventional solar photovoltaic cells convert sunlight into electricity, which is then used by an electrochemical device called an electrolyzer to convert low-energy reactants into energy-dense fuels or chemicals. In the second pathway, photoelectrolysis, the light-harvesting and electrochemical processes are performed in a single, integrated device known as a photoelectrochemical (PEC) cell. There are advantages and disadvantages associated with both pathways, but in general both technologies require advances in new materials and devices (reactors) to become economically competitive with conventional fossil fuels.

Reflecting the interdisciplinary nature of PEC and PV electrolysis devices, the strengths of this research program are at the intersections of chemical engineering, electrochemistry, electroanalytical chemistry, catalysis, materials science, and interfacial science and engineering. Additionally, most of our research projects rely on the use of in situ analytical techniques that are used to evaluate the properties and performance of materials and devices with high spatial resolution. In other words, we rely on advanced measurement tools that can “see”, at very small length scales, how these materials and devices perform while they are operating in a (photo)electrochemical environment that mimics conditions that would be encountered in real-world applications.  Analytical tools commonly used in our lab include a high speed video camera, in situ spectroelectrochemistry, and scanning probe microscopies (SPM). By pushing the limits of what these tools can teach us, we seek to answer fundamental questions in photocatalytic, photovoltaic, and electrochemical science, and apply that knowledge to improve the performance of real-world energy conversion devices and systems.

Ph.D., masters, and undergraduate students are integral to this research group. Additionally, we actively seek and welcome collaborations with university, national lab, and industrial partners with common interests including, but not limited to, the solar, electrochemical, and chemical industries.