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

Abstract

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 H3PO4 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 H3PO4 85% by the three different mixing ratios 1:0, 1:1, and 1:3 (w/w) and then pyrolysis under N2 flow maintained at 500 °C for 1 h. The performance as the electrode for an EDLC was evaluated in 1 mol L−1 H2SO4 solution for the H3PO4-activated samples. The SSA and pore volumes were drastically increased after activation. The maximum SSA and pore volume were 1212 m2 g−1 and 1.43 cm3 g−1, respectively for the biochar activated at 400 °C with a weight mixing ratio 1:3 (w/w) between the fern and H3PO4 acid while these values of the biochar at 400 °C were 12 m2 g−1 and 0.02 cm3 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 H3PO4 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.

Evolution of physico-chemical properties of Dicranopteris linearis-derived activated carbon under various physical activation atmospheres

“…Compared with various D. linearis- derived chars from different pyrolysis techniques in our previous studies, which showed their SSA values in the range from 40 to 524 m 2 g −1 , the CO 2 /steam-activated chars expressed a much higher SSA 22 . More interestingly, the performance of CO 2 and steam in boosting SSA was at least equal to that of H 3 PO 4 28 , and this finding is well aligned with previous studies using the same method 29 , 30 .…”

Biomass waste-based material: Electrochemical performance and CO2 uptake capability

“…Figure 6 illustrates a distinct increase in electrochemical capacity of the A-xKC samples, characterized by rectangular CV shapes and triangular GCD shapes, both typical of Electric Double-Layer Capacitor (EDLC) electrode materials (Trinh et al 2020). A-xKC had a capacitance of both CV and GCD greater than 160 F g − 1 , which is considered better than biochar prepared from some bark materials such as willow bark (Hobisch et al 2020), tree bark (Momodu et al 2017).…”

The Application of the Activated Carbon from Cordia africana Leaves for Adsorption of Chromium (III) from an Aqueous Solution

“…Tis optimization process was intended to produce high biochar yields and specifc surface area. About 30 g of powdered leaves was impregnated with H 3 PO 4 (85% w/w, Merck) at the ratio of 1 : 1 with diferent acid concentrations (25%, 55%, and 85%) for 24 h and heated in an oven at 60 °C [23]. Tis impregnation ratio was taken constantly throughout the experiment.…”