Abstract
Semiconductor-metal hybrid nanostructures offer a highly controllable platform for light-induced charge separation, with direct relevance for their implementation in photocatalysis. Advances in the synthesis allow for control over the size, shape and morphology, providing tunability of the optical and electronic properties. A critical determining factor of the photocatalytic cycle is the metal domain characteristics and in particular its size, a subject that lacks deep understanding. Here, using a well-defined model system of cadmium sulfide-gold nanorods, we address the effect of the gold tip size on the photocatalytic function, including the charge transfer dynamics and hydrogen production efficiency. A combination of transient absorption, hydrogen evolution kinetics and theoretical modelling reveal a non-monotonic behaviour with size of the gold tip, leading to an optimal metal domain size for the most efficient photocatalysis. We show that this results from the size-dependent interplay of the metal domain charging, the relative band-alignments, and the resulting kinetics.
| Original language | English |
|---|---|
| Article number | 10413 |
| Journal | Nature Communications |
| Volume | 7 |
| DOIs | |
| State | Published - 19 Jan 2016 |
Bibliographical note
Funding Information:We thank Dr Vitaly Gutkin from the Unit for Nanocharacterization at the Hebrew University for assistance in the X-ray photoelectron spectroscopy measurements. The research leading to these results has received funding from The Israel Science Foundation (grant no. 1560/13) and the Ministry of Science, Technology and Space, Israel & the Directorate General for Political and Security Affairs of the Ministry of Foreign Affairs, Italy. U.B. thanks the Alfred & Erica Larisch memorial chair. G.C. acknowledges support by the EC under Graphene Flagship (contract no. CNECT-ICT-604391). Y.B.S. acknowledges support by the Ministry of Science, Technology and Space, Israel & the Camber Scholarship.
