Nitrogen-doped graphenic foam synthesized by solvothermal-based process: Effect of pyrolysis temperature on the material properties

• Published in: Microporous and mesoporous materials 2020-06, Vol.300, p.110165, Article 110165
• Main Authors: Moumaneix, Lilian, Fontana, Sébastien, Dossot, Manuel, Lapicque, François, Hérold, Claire
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Graphene foam; Inorganic chemistry; Nitrogen doping; Solvothermal-based process; Surface characterization; Synthetic microporous material
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2020.110165

Extraordinary properties of graphenic materials no longer need to be demonstrated. Nitrogen doping has been known to broaden the graphene application fields, especially for catalysis purposes. The present work reports a solvothermal-based process for the synthesis of a nitrogen-doped graphenic foam with up to 2.6 at.% nitrogen, exhibiting the inherent properties of graphenic materials with high textural properties and surface areas as high as 2243 m2 g−1. This study aims to give a better understanding of the influence of the pyrolysis treatment on the properties of the produced material for optimization of the synthesis in view to fuel cell applications. Several cross-linked techniques such as transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy, nitrogen physisorption at 77 K and X-ray photoelectron spectroscopy have been employed to give a complete, precise characterization of the elaborated N-doped graphenic foams, leading to optimized conditions for the pyrolysis step. Pyrolysis at 850 °C has been found to allow the best compromise in terms of purity, homogeneity and crystallinity, with high fractions of pyrrolic, pyridinic and graphitic N-substitution that are known to greatly enhance the material catalytic properties. An oxidative degradation process was also evidenced for temperatures above 875 °C, leading to far lower graphene amounts. [Display omitted] •Microporous N-doped graphenic foams possess a very high specific surface area.•Nitrogen is mostly inserted in the graphenic network.•The pyrolysis temperature is a key parameter for the surface N-functions.•N-doped graphenic foam is a promising material for electrocatalytic applications.