Carbonization and H3PO4 activation of fern Dicranopteris linearis and electrochemical properties for electric double layer capacitor electrode

• Published in: Scientific reports 2020-11, Vol.10 (1), p.19974-19974, Article 19974
• Main Authors: Trinh, Trang K., Tsubota, Toshiki, Takahashi, Shuto, Mai, Nga T., Nguyen, Minh N., Nguyen, Nam H.
• Format: Article
• Language: English
• Subjects: 639/301; 704/172; Capacitance; Charcoal; Climate change; Dicranopteris linearis; Electrical properties; Electrodes; Ferns; Greenhouse gases; Humanities and Social Sciences; multidisciplinary; Pyrolysis; Science; Science (multidisciplinary); Sulfuric acid
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-77099-7

Today, the world’s climate change is a growing problem, plant carbon sequestration is one of the effective ways to mitigate climate change by reducing greenhouse gases, mostly carbon gases. Dicranopteris linearis ( D. linearis ), a common fern species in the tropic or subtropic ecoregions, has been recently recognized as a potential feedstock to produce highly porous biochar. This study aims to enhance the specific surface area (SSA) and pore volumes of biochars derived from the D. linearis by H 3 PO 4 activation and examine electrical properties of the activated biochars and their possible usage for the electric double-layer capacitor (EDLC) electrode. The treated raw fern was activated with H 3 PO 4 85% by the three different mixing ratios 1:0, 1:1, and 1:3 (w/w) and then pyrolysis under N 2 flow maintained at 500 °C for 1 h. The performance as the electrode for an EDLC was evaluated in 1 mol L −1 H 2 SO 4 solution for the H 3 PO 4 -activated samples. The SSA and pore volumes were drastically increased after activation. The maximum SSA and pore volume were 1212 m 2  g −1 and 1.43 cm 3  g −1 , respectively for the biochar activated at 400 °C with a weight mixing ratio 1:3 (w/w) between the fern and H 3 PO 4 acid while these values of the biochar at 400 °C were 12 m 2  g −1 and 0.02 cm 3  g −1 , respectively. The biochar activated at 600 °C with the mixing ratio 1:1 (w/w) showed the maximum capacitance value, ca . 108 F g −1 at 1 mV s −1 . The activation using H 3 PO 4 showed a positive tendency to enhance electrochemical properties and it could be a premise toward a higher performance of EDLC from the D. linearis derived activated biochar.