Journal of Materials Science

, Volume 54, Issue 7, pp 5280–5293 | Cite as

Ultra-small amorphous carbon dots: preparation, photoluminescence properties, and their application as TiO2 photosensitizers

  • Peng Wu
  • Xueyun Wu
  • Wei Li
  • Yushan Liu
  • Zhijun Chen
  • Shouxin LiuEmail author
Chemical routes to materials


Ultra-small carbon quantum dots (s-CQDs) with excitation wavelength-independent fluorescence had been obtained by hydrothermal-followed acid precipitation method and were characterized by FT-IR, TEM, XPS, UV–Vis and XRD. It was found that as-prepared s-CQDs were amorphous spherical particles with an average diameter of 1.51 nm, and there were abundant hydroxyl and carbonyl groups on their surfaces. Moreover, fluorescence emission study found that the luminescence of s-CQDs was aroused by oxygen group decorated on its surface, and the fluorescence properties of s-CQDs were much different from those of large CQDs (l-CQDs), which showed higher quantum yield and better photoluminescence (PL) property than that of l-CQDs. The PL of s-CQDs possessed two emission centers and was exhibited to be excitation independent. When s-CQDs was used as photosensitizer for TiO2 to photocatalytic degradation of methylene blue under visible light irradiation, it showed significantly improved photocatalytic activities compared with 1-CQDs, and the degradation efficiency of methylene blue reached up to 96.6%. The high degradation efficiency was attributed to the ultra-small particle size, abundant acidic groups, and excellent optical properties of s-CQDs.



This work was supported by the National Natural Science Foundation of China (Grant Nos. 31570567, 31500467, and 61705063) and the Fundamental Research Funds for the Central Universities (2572017ET02). We thank Andrew Jackson, PhD, from Liwen Bianji, Edanz Group China (, for editing the English text of a draft of this manuscript.

Compliance with ethical standards

Conflicts of interest

The authors declare there is no conflict of interest regarding the publication of this paper.


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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.College of Materials Science and EngineeringNortheast Forestry UniversityHarbinPeople’s Republic of China
  2. 2.College of Environmental and Chemical EngineeringHeilongjiang University of Science and TechnologyHarbinPeople’s Republic of China

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