Synthesis of multi-application activated carbon from oak seeds by KOH activation for methylene blue adsorption and electrochemical supercapacitor electrode

• Main Authors: Seyed Abbas Borghei, Masoud Habibi Zare, Mojtaba Ahmadi, Mohammad Hasan Sadeghi, Azam Marjani, Saeed Shirazian, Mahdi Ghadiri
• Format: Article
• Language: English
• Published: Elsevier 2021-02-01
• Series: Arabian Journal of Chemistry
• Subjects: Activated carbon; Adsorbent; Supercapacitor; Methylene blue
• Online Access: http://www.sciencedirect.com/science/article/pii/S1878535220305190

In the current study, an oak as a non-expensive, renewable, and a biomass resource was used to generate a nano-porous activated carbon applicable in methylene blue adsorption from wastewater and energy storage equipment. Furnace activation in the temperature range of 450, 550, 650 and 750 °C was used for activated carbon synthesis after infusion with potassium hydroxide. The synthesized activated carbon was characterized using different techniques including nitrogen adsorption/desorption, scanning electron microscopy, and fourier-transform infrared spectroscopy. The results showed that temperature has significant effect on activated carbon efficiency. Specific surface and pore volumes increased with the enhancement of temperature until 650 °C, but then it was decreased. Pores volume was consisting of mesoporous and microporous structure. The highest surface area (2896 m2/g) and pores volume (1.554 cm3/g) was obtained for the sample prepared at 650 °C. Freundlich isotherm model is appropriate for methylene blue adsorption isotherm by the synthesized activated carbon. The maximum adsorption capacity of MB was obtained as 24 mg/g. Moreover, the synthesized activated carbon exhibited the highest specific capacitance when it was used as electrode (551 F/g at current density of 1 A/g) in 1 M sulphuric acid electrolyte and 96% specific capacitance was remained after 5000 charge-discharge cycles at a current density of 10 A/g.