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Title: Facile preparation of zinc oxide nanorods surrounded by graphene quantum dots both synthesized via separate pyrolysis procedures for photocatalyst application

Journal Article · · Materials Research Bulletin
; ;  [1]
  1. Condensed Matter Group, Department of Basic Sciences, Tarbiat Modares University, Jalal-Ale-Ahmad avenue, Tehran (Iran, Islamic Republic of)

Highlights: • ZnO NRs and GQDs were made separately via a simple and one-stage pyrolysis method. • Because of the employed compositing method, GQDs compactly surrounded the ZnO NRs. • Bandgap of ZnO NRs decreased from 3.2 to 2.8 eV after they were surrounded by GQDs. • Despite being inefficient alone, GQDs largely enhanced ZnO photocatalytic activity. • The mechanism was mainly attributed to the decrease in recombination rate of ZnO. - Abstract: A facile pyrolysis method was employed for separate synthesis of zinc oxide nanorods (ZnO NRs) and graphene quantum dots (GQDs) and the structures were composited. The structures were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and Fourier transform infrared (FTIR) spectroscopy. The structures were optically characterized by UV–vis and photoluminescence (PL) spectrometry techniques, showing that the absorption of ZnO NRs increases in the visible region after being surrounded by GQDs. Optical bandgaps of ZnO NRs and ZnO NRs/GQDs composite were estimated as 3.2 and 2.8 eV, respectively. Based on PL analysis, it was deduced that the generated electron-hole recombination rate of ZnO NRs decreases after being surrounded by GQDs. Finally, it was shown that our GQDs, despite being relatively inefficient separately, significantly enhance the photocatalytic activity of ZnO on methylene blue mainly through decreasing the e-h recombination rate of ZnO NRs.

OSTI ID:
22805394
Journal Information:
Materials Research Bulletin, Vol. 98; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
Country of Publication:
United States
Language:
English