Annealing-free synthesis of carbonaceous Nb{sub 2}O{sub 5} microspheres by flame thermal method and enhanced photocatalytic activity for hydrogen evolution

Journal Article · Mon Jun 15 00:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2015.02.005· OSTI ID:22475786

Ma, Xiaoqing; Chen, Yang; Li, Hui ^[1]; Cui, Xiaoli ^[1]; Lin, Yuehe ^[2]

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1. Department of Materials Science, Fudan University, Shanghai 200433 (China)
2. School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States)

Graphical abstract: Carbonaceous Nb{sub 2}O{sub 5} microspheres were firstly prepared by annealing-free flame thermal approach and its enhanced photocatalytic activity was demonstrated for hydrogen production. - Highlights: • Carbonaceous Nb{sub 2}O{sub 5} microspheres were prepared by annealing-free flame thermal approach in the first time. • Hydrolysis and incomplete combustion gave rise to Nb{sub 2}O{sub 5} incorporated with carbon. • Carbon species act as surface sensitizer to enhance photocatalytic activity. • It is possible to extend the strategy to develop various other metal oxides. - Abstract: An annealing-free synthesis of carbonaceous Nb{sub 2}O{sub 5} photocatalyst via a one-step flame assisted pyrolysis approach was proposed for the first time. Nearly amorphous carbonaceous Nb{sub 2}O{sub 5} microspheres were obtained directly through the facile and waste-free method. The presence of carbonate species was confirmed by means of EDS, XPS, BET and TEM. Both FT-IR and Raman analysis further revealed the existence form of carbon residuals for the resulted sample. UV–vis diffuse reflectance spectra showed the strong absorption of visible light and narrowed band gap for the carbon modified Nb{sub 2}O{sub 5}. On account of the vital role that carbon played in efficient electron-hole separation and light absorption, the hydrogen generation rate was 2.7 times that of the annealed and commercial Nb{sub 2}O{sub 5} samples. Further calcination can foster the crystallinity and expand specific surface area but lower the photocatalytic performance of as-prepared Nb{sub 2}O{sub 5} because of the elimination of carbon species. This work provides a new strategy for the preparation of carbonaceous Nb{sub 2}O{sub 5} candidates with enhanced photocatalytic activity.

• OSTI ID: 22475786
• Journal Information: Materials Research Bulletin, Vol. 66; Other Information: Copyright (c) 2015 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

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
ANNEALING
CARBON
CARBONATES
FOURIER TRANSFORMATION
HYDROGEN PRODUCTION
HYDROLYSIS
INFRARED SPECTRA
MICROSPHERES
MICROSTRUCTURE
NIOBIUM OXIDES
PHOTOCATALYSIS
SPECIFIC SURFACE AREA
SURFACE PROPERTIES
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
VISIBLE RADIATION
WASTES
X-RAY PHOTOELECTRON SPECTROSCOPY