Dr. Lewis’ research interests include artificial photosynthesis and electronic noses.  Technical details of these research topics focus on light-induced electron transfer reactions, both at surfaces and in transition-metal complexes, surface chemistry and photochemistry of semiconductor/liquid interfaces, novel uses of conducting organic polymers and polymer/conductor composites, and development of sensor arrays that use pattern recognition algorithms to identify odorants, mimicking the mammalian olfaction process.

Within JCAP, Dr. Lewis studies ways to harness sunlight to generate chemical fuel, specifically by splitting water to generate hydrogen.  These efforts have as their final goal the creation of a photoelectrochemical cell.  This cell consists of nanostructured arrays of anodes and cathodes, oxidation and reduction catalysts, and a central conductive membrane that allows for ion exchange.  Various subgroups are addressing the challenges inherent in developing this cell.


Recent Publications

Popczun, E. et al. Highly Branched Cobalt Phosphide Nanostructures for Hydrogen-Evolution Electrocatalysis. Journal of Materials Chemistry A, DOI: 10.1039/C4TA06642A (2015).

Sun, K. et al. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films. PNAS 112, 12, 3612–3617, DOI: 10.1073/pnas.1423034112(2015).

Verlage, E. et al. A Monolithically Integrated, Intrinsically Safe, 10% Efficient, Solar-Driven Water-Splitting System Based on Active, Stable Earth-Abundant Electrocatalysts in Conjunction with Tandem III-V Light Absorbers Protected by Amorphous TiO2 Films. Energy & Environmental Science, DOI: 10.1039/C5EE01786F (2015).

Hu, S. et al. Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation. Science 344, 1005-1009, DOI: 10.1126/science.1251428 (2014).

Hu, S., Xiang, C. X., Haussener, S., Berger, A. D. & Lewis, N. S. An analysis of the optimal band gaps of light absorbers in integrated tandem photoelectrochemical water-splitting systems. Energy & Environmental Science 6, 2984-2993, DOI: 10.1039/c3ee40453f (2013).


Additional Information

Lewis Group:  http://nsl.caltech.edu/