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Title: Enhanced photoelectrochemical water splitting from Si quantum dots/TiO{sub 2} nanotube arrays composite electrodes

Graphical abstract: Si quantum dots were firstly applied to modify TiO{sub 2} nanotubes and enhanced visible light response was demonstrated for the resulted Si QDs/TiO{sub 2} nanocomposite. Si QDs are promising in photoelectrochemical water splitting and photocatalysis since their low cost, abundance and environmentally-friendliness. - Highlights: • A novel nanocomposite Si QDs/TiO{sub 2} nanotubes was fabricated and characterized. • Enhanced photoelectrochemical water splitting was firstly demonstrated for Si QDs/TiO{sub 2}. • The visible light response of TiO{sub 2} increased with the presence of Si QDs. - Abstract: This work firstly introduced Si quantum dots (QDs) to modify TiO{sub 2} nanotube arrays for photoelectrochemical water splitting. A systematic study using surface and optical characterization tools reveals the nature of the combination of Si QDs and TiO{sub 2} nanotube arrays. Scanning electron microscopy and X-ray photoelectron spectroscopy results show that Si QDs were assembled on the surface of vertically aligned TiO{sub 2} nanotube arrays. The UV–vis diffuse reflectance spectra indicate the improved visible light absorbance. The enhanced photoelectrochemical water splitting was demonstrated under visible light illumination and the photocurrent density was 1.6 times larger than that of pristine TiO{sub 2} electrodes. Electrochemical impedance behavior was measured for the electrodes and the impedancemore » is slightly reduced for the nanocomposite electrode with the presence of Si QDs. This work demonstrated that Si QDs would be a novel and effective choice for improving the utilization of visible light for TiO{sub 2} nanotubes.« less
Authors:
 [1] ;  [1] ; ;  [2] ;  [3]
  1. Department of Materials Science, Fudan University, Shanghai 200433 (China)
  2. Department of Optical Science and Engineering, and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433 (China)
  3. School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States)
Publication Date:
OSTI Identifier:
22475782
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 66; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ELECTROCHEMISTRY; ILLUMINANCE; NANOTUBES; OPTICAL PROPERTIES; PHOTOCATALYSIS; QUANTUM DOTS; SCANNING ELECTRON MICROSCOPY; SURFACES; SYNTHESIS; TITANIUM OXIDES; VISIBLE RADIATION; WATER; X-RAY PHOTOELECTRON SPECTROSCOPY