Ultrasonic-assisted pyrolyzation fabrication of reduced SnO2–x /g-C3N4 heterojunctions: Enhance photoelectrochemical and photocatalytic activity under visible LED light irradiation

Journal Article · Fri Apr 29 00:00:00 EDT 2016 · Nano Research

DOI:https://doi.org/10.1007/s12274-016-1088-8· OSTI ID:1376896

Li, Kai; Zeng, Xiaoqiao; Gao, Shanmin; Ma, Lu; Wang, Qingyao; Xu, Hui; Wang, Zeyan; Huang, Baibiao; Dai, Ying; Lu, Jun

Novel SnO_2–x/g-C₃N₄ heterojunction nanocomposites composed of reduced SnO_2–x nanoparticles and exfoliated g-C₃N₄ nanosheets were prepared by a convenient one-step pyrolysis method. The structural, morphological, and optical properties of the as-prepared nanocomposites were characterized in detail, indicating that the aggregation of g-C₃N₄ nanosheets was prevented by small, well-dispersed SnO_2–x nanoparticles. The ultraviolet–visible spectroscopy absorption bands of the nanocomposites were shifted to a longer wavelength region than those exhibited by pure SnO₂ or g-C₃N₄. The charge transfer and recombination processes occurring in the nanocomposites were investigated using linear scan voltammetry and electrochemical impedance spectroscopy. Under 30-W visible-light-emitting diode irradiation, the heterojunction containing 27.4 wt.% SnO_2–x exhibited the highest photocurrent density of 0.0468 mA·cm–2, which is 33.43 and 5.64 times larger than that of pure SnO₂ and g-C₃N₄, respectively. The photocatalytic activity of the heterojunction material was investigated by degrading rhodamine B under irradiation from the same light source. Kinetic study revealed a promising degradation rate constant of 0.0226 min-1 for the heterojunction containing 27.4 wt.% SnO_2–x, which is 32.28 and 5.79 times higher than that of pure SnO₂ and g-C₃N₄, respectively. The enhanced photoelectrochemical and photocatalytic performances of the nanocomposite may be due to its appropriate SnO_2–x content and the compact structure of the junction between the SnO_2–x nanoparticles and the g-C₃N₄ nanosheets, which inhibits the recombination of photogenerated electrons and holes.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Vehicle Technologies Office; National Basic Research Program of China
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1376896
• Journal Information: Nano Research, Vol. 9, Issue 7; ISSN 1998-0124
• Publisher: Springer
• Country of Publication: United States
• Language: English