This paper by Spanish researchers Navarro-Suarez et al. describes the development of a new technology to produce lignin-based nanoporous carbon with narrow and tunable pores. This novel material was prepared by chemical activation of natural lignin at 900˚C, and it was tested as an electrode material for electrical double-layer capacitors.
Characterization of the morphological, chemical and electrical properties of this new material was done by different methods including SEM, HRTEM, EDX, electrochemical analysis and Raman microscopy. Raman characterization was performed with a Nanonics Multiview 2000 integrated with a Raman spectrometer. Such an integrated system enables characterization of morphological properties with simultaneous chemical characterization.
The authors shows that there are ordered and disordered carbon regions and presence of few layer graphene (FLG) embedded into the amorphous carbon matrix. The Raman spectral imaging and ratio between ID and IGRaman peaks of carbon confirmed SEM and HRTEM morphological results. Further electrochemical studies showed that capacitance value of 6.87 Fg-1 can be obtained.
Thus, the obtained results demonstrated that nonporous carbon with tunable pore size can be achieved by using a natural material such as lignin and can be effectively used as electrodes material in energy storage applications.
Distribution obtained by Raman spectral imaging of the ordered and disordered areas inside a particle for samples (a) 2, (b) 4 and (c) 6.
Color scale on the right varies with the ID/IG values from 0.0 (dark blue) to 1.2 (dark red).
Published: RSC Advances, 2014, 4, 48336-48343
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