Microstructural analysis of nitrogen-doped char by Raman spectroscopy: Raman shift analysis from first principles. (15th October 2020)

• Record Type: Journal Article
• Authors: Ayiania, Michael; Weiss-Hortala, Elsa; Smith, Matthew; McEwen, Jean-Sabin; Garcia-Perez, Manuel
• Is Part Of: Carbon. Volume 167(2020)
• Page Start: 559
• Page End: 574
• Publication Date: 2020-10-15
• Subjects: Density functional theory calculations -- N-doped carbons -- Raman spectroscopy; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2020.05.055
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Nitrogen-doped materials are known to possess unique functional properties, making these materials potentially useful for environmental applications, heterogeneous catalysis, and electronics. In this paper we constructed first principles-based models of various polyaromatic structures containing N functionalities to better understand the effect of these functional groups on char Raman spectra. The presence of N functional groups induces active vibrations in the regions between 1400 and 1550 cm −1 and 1605-1650 cm −1 . We used these insights to inform the deconvolution of N-doped cellulose char produced between 350 and 700 °C using cellulose/melamine blends 2:1. A consistent increase in the intensity of the D and G bands is observed with temperature, which is related to an increase in size of the aromatic cluster. A consistent decrease in the A (the valley region) band is related to the loss of heteroatoms (mainly N and O) as the carbonization temperature increases from 350 to 700 °C. Although the modeling results reported in this manuscript are used to inform the deconvolution of N-doped char Raman spectra, they are also relevant to study other nanocarbon-based materials. Graphical abstract: Image 1