Using nanocrystal surface chemistry to afford functional materials for energy conversion

Department

Chemistry

Abstract

materials for energy conversion and storage. Gains in solar electricity and battery technologies are evidenced by the availability of commercial products. However viable solar fuel platforms—where the energy in sunlight is used to form storable fuels such as hydrogen gas—have not yet been realized. The need for rationally designed functional materials from earth-abundant sources motivates the synthetic strategies proposed in this work. Our key scientific objective is to demonstrate controlled substitutional doping of zinc sulfide nanocrystals (ZnS NCs) via cation exchange (CE). ZnS NCs are attractive materials for solar hydrogen evolution because of the material’s high conduction band energy, which is sufficient to reduce hydrogen ions in aqueous solutions. However, the wide bandgap of ZnS (~3.7 eV) limits the amount of sunlight absorbed such that the majority of energy in the solar spectrum cannot be harnessed by ZnS alone. Substitutionally doping cations into the host ZnS NCs is a known strategy for tuning the optical, electronic, and magnetic properties of ZnS. Here we describe modifications of NC surface chemistry and the use of dopant sterics to enable controllable doping of ZnS NCs.

Presentation format

Poster

Poster Number

122

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Using nanocrystal surface chemistry to afford functional materials for energy conversion

materials for energy conversion and storage. Gains in solar electricity and battery technologies are evidenced by the availability of commercial products. However viable solar fuel platforms—where the energy in sunlight is used to form storable fuels such as hydrogen gas—have not yet been realized. The need for rationally designed functional materials from earth-abundant sources motivates the synthetic strategies proposed in this work. Our key scientific objective is to demonstrate controlled substitutional doping of zinc sulfide nanocrystals (ZnS NCs) via cation exchange (CE). ZnS NCs are attractive materials for solar hydrogen evolution because of the material’s high conduction band energy, which is sufficient to reduce hydrogen ions in aqueous solutions. However, the wide bandgap of ZnS (~3.7 eV) limits the amount of sunlight absorbed such that the majority of energy in the solar spectrum cannot be harnessed by ZnS alone. Substitutionally doping cations into the host ZnS NCs is a known strategy for tuning the optical, electronic, and magnetic properties of ZnS. Here we describe modifications of NC surface chemistry and the use of dopant sterics to enable controllable doping of ZnS NCs.