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Insights into Charge Transfer at an Atomically Precise Nanocluster/Semiconductor Interface
Author(s) -
Wang Yu,
Liu XiaoHe,
Wang Qiankun,
Quick Martin,
Kovalenko Sergey A.,
Chen QingYun,
Koch Norbert,
Pinicola
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201915074
Subject(s) - semiconductor , heterojunction , nanoparticle , photocatalysis , band gap , materials science , ultrafast laser spectroscopy , cluster (spacecraft) , absorption (acoustics) , catalysis , plasmon , optoelectronics , charge carrier , charge (physics) , nanotechnology , photochemistry , spectroscopy , chemistry , physics , biochemistry , quantum mechanics , computer science , composite material , programming language
The deposition of an atomically precise nanocluster, for example, Ag 44 (SR) 30 , onto a large‐band‐gap semiconductor such as TiO 2 allows a clear interface to be obtained to study charge transfer at the interface. Changing the light source from visible light to simulated sunlight led to a three orders of magnitude enhancement in the photocatalytic H 2 generation, with the H 2 production rate reaching 7.4 mmol h −1 g catalyst −1 . This is five times higher than that of TiO 2 modified with Ag nanoparticles and even comparable to that of TiO 2 modified with Pt nanoparticles under similar conditions. Energy band alignment and transient absorption spectroscopy reveal that the role of the metal clusters is different from that of both organometallic complexes and plasmonic nanoparticles: A type II heterojunction charge‐transfer route is achieved under UV/Vis irradiation, with the cluster serving as a small‐band‐gap semiconductor. This results in the clusters acting as co‐catalysts rather than merely photosensitizers.