(3cc) Photovoltaics and Catalysis for Photoelectrochemical Applications

The energy available from sunlight striking Earth is orders of magnitude larger than the amount of energy currently consumed by mankind, yet our current energy system is dominated by CO₂–emitting, non-renewable fossil fuels. In order for solar technology to achieve widespread replacement of fossil fuels, major developments must be made in three interrelated areas: (i) solar conversion efficiency, (ii) materials and manufacturing costs, and (iii) energy storage. In my future research lab, I will explore solar and energy conversion technology that strives to address and overcome challenges in all three of these areas. A deep understanding of the trade-offs between each area is crucial for all levels of solar research, and I believe that there is a large and untapped potential for applying chemical engineering principles to evaluate these trade-offs and thereby optimize the overall worth of solar energy systems.

Central to my future research will be photoelectrochemical (PEC), solar thermal, and related hybrid technologies that are capable of directly converting sunlight into storable chemical and/or thermal energy.  By generating energy that can be stored, PEC and solar thermal processes overcome the problem of solar intermittency, an inherent weakness of photovoltaic technology. My research will build off of my past and current research experiences at the University of Delaware and the National Institute of Standards and Technology (NIST). At the University of Delaware, my thesis research was focused on the development of hydrogen evolution catalysts and PEC device design, allowing me to gain broad expertise in the fields of electrochemistry, catalysis, and photovoltaics. At NIST, my current research efforts are centered on the development of well-defined metal-oxide-semiconductor (MOS) photoelectrodes for PEC applications. As I will discuss in my oral presentation at this year’s meeting, these MOS structures hold great potential for efficient PEC energy conversion because they are well-suited for overcoming the fundamental efficiency/stability trade-off that so commonly hinders conventional photoelectrodes. The well-defined and ordered geometries of these MOS structures also make them ideal for micro-scale modeling and experimental efforts aimed at better understanding charge transfer phenomena in MOS-based photoelectrodes. In addition to presenting past, current, and future research efforts, I will also discuss my future teaching and outreach endeavors at this poster session.

Post-doctoral advisors: Dr. Thomas Moffat and Dr. Alec Talin, National Institute of Standards and Technology

Ph.D. advisors:  Prof. Jingguang G. Chen and Prof. Robert Birkmire, University of Delaware

Selected publications

1. D.V. Esposito, S.T. Hunt, Y. Kimmel, and J.G. Chen, “A New Class of Electrocatalysts for Hydrogen Production from Water Electrolysis: Metal Monolayers Supported on Low-Cost Transition Metal Carbides”. Journal of the American Chemical Society, vol. 134, 2012.
2. D.V. Esposito and J.G. Chen, “Monolayer Platinum Supported on Tungsten Carbides as Low-Cost Electrocatalysts: Opportunities and Limitations”.  Energy & Environmental Science, vol. 4, 3900-3912, 2011. (Invited perspective article)
3. D.V. Esposito, Y.  Chang, J.G. Chen, R.W. Birkmire, and N. Gaillard, “Hydrogen Production from Photo-driven Electrolysis of Biomass-derived Oxygenates: A Case Study on Methanol using Pt-modified WO₃ Thin Film Electrodes”. International Journal of Hydrogen Energy, vol. 36, 9632-9644, 2011.
4. D.V. Esposito, S.T. Hunt, A.L. Stottlemyer, K.D. Dobson, B.E. McCandless, R.W. Birkmire, and J.G. Chen, “Low-Cost Hydrogen Evolution Catalysts Based on Monolayer Platinum on Tungsten Monocarbide (WC) Substrates”.  Angewandte Chemie International Edition, vol. 49, 9859-9862, 2010. (Cover article and press release)
5. D.V. Esposito, O.Y. Goue, K.D. Dobson, B.E. McCandless, J.G. Chen, and R.W. Birkmire, “A New Photoelectrochemical Test Cell and Its Use for a Combined Two- and Three-Electrode Approach to Cell Testing”.  Review of Scientific Instruments, vol. 80, 125107, 2009.