Simultaneous optimization of colloidal stability and interfacial charge transfer efficiency in photocatalytic Pt/CdS nanocrystals

Abstract

Colloidal stability and efficient interfacial charge transfer in semiconductor nanocrystals are of great importance for photocatalytic applications in aqueous solution since they provide long-term functionality and high photocatalytic activity, respectively. However, colloidal stability and interfacial charge transfer efficiency are difficult to optimize simultaneously since the ligand layer often acts as both a shell stabilizing the nanocrystals in colloidal suspension and a barrier reducing the efficiency of interfacial charge transfer. Here, we show that, for cysteine-coated, Pt-decorated CdS nanocrystals and Na2SO3 as hole scavenger, triethanolamine (TEOA) replaces the original cysteine ligands in situ and prolongs the highly efficient and steady H2 evolution period by more than a factor of 10. It is shown that Na2SO3 is consumed during H2 generation while TEOA makes no significant contribution to the H2 generation. An apparent quantum yield of 31.5%, a turnover frequency of 0.11 H2/Pt/s, and an interfacial charge transfer rate faster than 0.3 ps were achieved in the TEOA stabilized system. The short length, branched structure and weak binding of TEOA to CdS as well as sufficient free TEOA in the solution are the keys to enhancing colloidal stability and maintaining efficient interfacial charge transfer at the same time. Additionally, TEOA is commercially available and cheap, and we anticipate that this approach can be widely applied in many photocatalytic applications involving colloidal nanocrystals.

Publication DOI: https://doi.org/10.1021/acsami.6b09364
Divisions: College of Engineering & Physical Sciences
College of Engineering & Physical Sciences > Aston Institute of Materials Research (AIMR)
College of Engineering & Physical Sciences > Energy and Bioproducts Research Institute (EBRI)
Additional Information: Funding: EPSRC Laser Loan Pool (EP/G03088X/1). The underlying EPSRC funded data in this paper is available from http://dx.doi.org/10.17638/datacat.liverpool.ac.uk/208.
Uncontrolled Keywords: aggregation-free,electron transfer,hole scavenging,water splitting,photocatalysis; solar fuels; transient absorption spectroscopy,Materials Science(all)
Publication ISSN: 1944-8252
Last Modified: 11 Jan 2024 08:10
Date Deposited: 19 Aug 2019 10:09
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://pubs.acs ... /acsami.6b09364 (Publisher URL)
PURE Output Type: Article
Published Date: 2016-11-02
Published Online Date: 2016-10-19
Accepted Date: 2016-10-11
Submitted Date: 2016-07-29
Authors: Wei, Li (ORCID Profile 0000-0003-4036-467X)
Lee, Jonathan
Jäckel, Frank

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