Solar fuels research at LPI

Solar energy is the ultimate renewable energy source, and its efficient conversion into electronic energy is an important challenge. However, sunlight is intermittent and regionally variable, so the storage and transport of the energy is necessary for its widespread use. Electronic energy suffers losses when transmitted over long distances or when stored in conventional batteries. An attractive alternative is to store the sun’s energy directly in chemical bonds by the photoelectrochemical generation of “Solar Fuels”.

The Solar Fuels subgroup at LPI is aimed at developing materials and processes for clean and renewable chemical fuel generation from sunlight, namely via water splitting to produce hydrogen or carbon dioxide reduction to form hydrocarbons. This employs the concept of photoelectrochemistry, encompassing the solid state physics of light absorption and charge separation, the electrochemistry of semiconductor/catalyst/liquid interfaces, and the chemical engineering of gas generation, electrolyte management, and cell design.

Selected publications

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J Luo, JH Im, MT Mayer, M Schreier, et al. Science, 2014

We demonstrated standalone water splitting exceeding 12% solar-to-hydrogen by combining two perovskite photovoltaic cells with two identical bifunctional and earth-abundant catalysts based on Ni-Fe hydroxides.

doi.wiley.com/10.1002/adfm.201301106

Tilley, Schreier, Azevedo, et al. Advanced Functional Materials, 2014

A new benchmark for stable, high-performance Cu2O photocathodes was achieved by employing electrodeposited RuOx.

pubs.rsc.org/en/content/articlelanding/2014/ee/c4ee02160f#!divAbstract

 J Azevedo, L Steier, P Dias, M Stefik, M Graetzel, SD Tilley, et al. Energy & Environmental Science, 2014

A simple hydrothermal treatment enables a highly stable copper oxide-based photocathode for H2 production.

pubs.acs.org/doi/abs/10.1021/jp509719d

P. Cendula, S.D. Tilley, et al. J. Phys. Chem. C 2014
A physical model is presented for the semiconductor electrode of a photoelectrochemical cell. Our model calculations are suitable to enhance understanding and improve the properties of semiconductors for photoelectrochemical water splitting.

pubs.rsc.org/en/content/articlelanding/2014/ee/c4ee03454f#!divAbstract

M. Schreier, P. Gao, M.T. Mayer, J. Luo, T. Moehl, M.K. Nazeeruddin, S.D. Tilley, M. Gratzel

Photoelectrochemical reduction of CO2 to CO was driven by a TiO2-protected Cu2O photocathode paired with a rhenium bipyridyl catalyst.

onlinelibrary.wiley.com/doi/10.1002/adfm.201402742/abstract

   L. Steier, et al.

Fe2O3 photoanodes combined with underlayers and overerlayers of different oxides produce enhanced performance, and the nature of these enhancements was studied in detail using electrochemical impedance spectroscopy.

pubsdc3.acs.org/doi/full/10.1021/jacs.5b12157

M Schreier, J Luo, P Gao, T Moehl, MT Mayer, M Graetzel. J. Am. Chem. Soc. 2016
The immobilization of rhenium-containing CO2 reduction catalysts on the surface of a protected Cu2O-based photocathode enabled a photofunctional unit combining the advantages of molecular catalysts with inorganic photoabsorbers.