Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Mechanistic insights into the photocatalytic properties of metal nanocluster/graphene ensembles. Examining the role of visible light in the reduction of 4-nitrophenol
Δημιουργός/Συγγραφέας:	Koklioti M.A. Skaltsas T. Sato Y. Suenaga K. Stergiou A. [EL] Ταγματάρχης, Νίκος[EN] Tagmatarchis, Nikos
Εκδότης:	Royal Society of Chemistry
Ημερομηνία:	2017
Γλώσσα:	Αγγλικά
ISSN:	2040-3364
DOI:	10.1039/c7nr02944f
Άλλο:	PubMed ID: 28675211
Περίληψη:	Metal nanoclusters (MNCs) based on silver and gold, abbreviated as AgNCs and AuNCs, respectively, were synthesized and combined with functionalized graphene, abbreviated as f-G, forming novel MNC/f-G ensembles. The preparation of MNCs/f-G was achieved by employing attractive electrostatic interactions developed between negatively charged MNCs, attributed to the presence of carboxylates due to α-lipoic acid employed as a stabilizer, and positively charged f-G, attributed to the presence of ammonium units as addends. The realization of MNC/f-G ensembles was established via titration assays as evidenced by electronic absorption and photoluminescence spectroscopy as well as scanning transmission electron microscopy (STEM) and energy-dispersive X-ray (EDX) spectroscopy analyses. Photoinduced charge-transfer phenomena were inferred within MNCs/f-G, attributed to the suppression of MNC photoluminescence by the presence of f-G. Next, the MNC/f-G ensembles were successfully employed as proficient catalysts for the model reduction of 4-nitrophenol to the corresponding 4-aminophenol as proof for the photoinduced hydrogen production. Particularly, the reduction kinetics decelerated by half when bare MNCs were employed vs. the MNC/f-G ensembles, highlighting the beneficial role of MNCs/f-G in catalysing the process. Furthermore, AuNCs/f-G displayed exceptionally higher catalytic activity both in the dark and under visible light illumination conditions, which is ascribed to three synergistic mechanisms, namely, (a) hydride transfer from Au-H, (b) hydride transfer from photogenerated Au-H species, and (c) hydrogen produced by the photoreduction of water. Finally, recycling and re-employing MNCs/f-G in successive catalytic cycles without loss of activity toward the reduction of 4-nitrophenol was achieved, thereby highlighting their wider applicability.
Τίτλος πηγής δημοσίευσης:	Nanoscale
Τόμος/Κεφάλαιο:	9
Τεύχος:	27
Σελίδες:	9685-9692
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Φασματοσκοπία[EN] Spectroscopy
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2017 The Royal Society of Chemistry.
Σημειώσεις:	Japan Society for the Promotion of Science, KAKEN: 16H06333, 16K05948; Japan Science and Technology Agency, JST; General Secretariat for Research and Technology, GSRT MIS: 5002409 Partial financial support by the General Secretariat for Research and Technology, Greece, through project "Advanced Materials and Devices" (MIS: 5002409) to NT is acknowledged. YS and KS acknowledge financial support from JSPS KAKENHI (grant numbers JP16 K05948 and JP16H06333) and the JST Research Acceleration Program.
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο