The Other Dimension-Tuning Hole Extraction via Nanorod Width

Nanomaterials (Basel). 2022 Sep 25;12(19):3343. doi: 10.3390/nano12193343.

Abstract

Solar-to-hydrogen generation is a promising approach to generate clean and renewable fuel. Nanohybrid structures such as CdSe@CdS-Pt nanorods were found favorable for this task (attaining 100% photon-to-hydrogen production efficiency); yet the rods cannot support overall water splitting. The key limitation seems to be the rate of hole extraction from the semiconductor, jeopardizing both activity and stability. It is suggested that hole extraction might be improved via tuning the rod's dimensions, specifically the width of the CdS shell around the CdSe seed in which the holes reside. In this contribution, we successfully attain atomic-scale control over the width of CdSe@CdS nanorods, which enables us to verify this hypothesis and explore the intricate influence of shell diameter over hole quenching and photocatalytic activity towards H2 production. A non-monotonic effect of the rod's diameter is revealed, and the underlying mechanism for this observation is discussed, alongside implications towards the future design of nanoscale photocatalysts.

Keywords: hole extraction; hydrogen; photocatalysis; seeded rods; semiconductor nanorods; transient absorption.

Grants and funding

L.A acknowledges funding by the Israeli Ministry of National Infrastructures, Energy and Water Resources (grant number 218-11-044). NGP gratefully acknowledges funding from the European Union’s Horizon 2020 research and innovation programme through a Marie Sklodowska-Curie Individual Fellowship (grant agreement no. 798409-HMST-PC). M.M. and M.W. acknowledge funding by the German Research Foundation (DFG) under Project No. 364549901–TRR234 (CataLight, B4). Funding was provided by a “Nevet” grant from the Grand Technion Energy Program (GTEP) and a Technion VPR Berman Grant for Energy Research to N.A.