Improved Efficiency and Stability of Cadmium Chalcogenide Nanoparticles by Photodeposition of Co-Catalysts

Abstract

The production of hydrogen by photocatalytic water splitting is a potentially clean and renewable source for hydrogen fuel. Cadmium chalcogenides are attractive photocatalysts because they have the potential to convert water into hydrogen and oxygen using photons in the visible spectrum. Cadmium sulfide rods with embedded cadmium selenide quantum dots (CdSe@CdS) are particularly attractive because of their high molar absorptivity in the UV-blue spectral region, and their energy bands can be tuned; however, two crucial drawbacks hinder the implementation of these materials in wide spread use: poor charge transfer and photochemical instability.

Utilizing photochemical deposition of co-catalysts onto CdSe@CdS substrates we can address each of these weaknesses. We report how novel co-catalyst morphologies can greatly increase efficiency for the water reduction half-reaction. We also report photostability for CdSe@CdS under high intensity 455nm light (a wavelength at which photocatalytic water splitting by CdSe@CdS is possible) by growing metal oxide co-catalysts on the surface of our rods.