title: High-yield synthesis and optical properties of g-C3N4.
abstract: Graphitic carbon nitride (g-C3N4), a metal-free semiconductor with a band gap of 2.7 eV, has received considerable attention owing to its fascinating photocatalytic performances under visible-light. g-C3N4 exhibits high thermal and chemical stability and non-toxicity such that it has been considered as the most promising photocatalyst for environmental improvement and energy conservation. Hence, it is of great importance to obtain high-quality g-C3N4 and gain a clear understanding of its optical properties. Herein, we report a high-yield synthesis of g-C3N4 products via heating of high vacuum-sealed melamine powder in an ampoule at temperatures between 450 and 650 °C. Using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), electron energy loss spectroscopy (EELS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the chemical composition and crystallization of the as-produced g-C3N4 are demonstrated. A systematic optical study of g-C3N4 is carried out with several approaches. The optical phonon behavior of g-C3N4 is revealed by infrared and Raman spectroscopy, and the emission properties of g-C3N4 are investigated using photoluminescence (PL) spectroscopy, while the photocatalytic properties are explored by the photodegradation experiment.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore. Qihua@ntu.edu.sg.
authors.forename: Yanwen
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authors.lastname: Yuan
authors.forename: Lulu
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authors.lastname: Zhang
authors.forename: Jun
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authors.lastname: Xing
authors.forename: M Iqbal Bakti
authors.initials: MI
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authors.forename: Xin
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authors.lastname: Lu
authors.forename: Kezhao
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authors.lastname: Du
authors.forename: Yongmei
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authors.lastname: Li
authors.forename: Xiao
authors.initials: X
authors.lastname: Hu
authors.forename: Shijie
authors.initials: S
authors.lastname: Wang
authors.forename: Aziz
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authors.lastname: Genç
authors.forename: Rafal
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authors.lastname: Dunin-Borkowski
authors.forename: Jordi
authors.initials: J
authors.lastname: Arbiol
authors.forename: Qihua
authors.initials: Q
authors.lastname: Xiong