Activated carbon is generally recognized as an applicable material for gas or liquid adsorption and electrochemical devices, such as electric double-layer capacitors (EDLCs). Owing to the continuous increase in its price, research aimed at discovering alternative materials and improving its fabrication yield is important. Herein, organic pigments were ingeniously employed to enhance the fabrication of high-surface-area activated carbon with remarkable efficiency. Moreover, the focus was centered on the assessment of activated carbon derived from 2,9-dimethylquinacridone, also known as CI Pigment Red 122 for its capacity to adsorb tetracycline (TC) and its applicability as an electrode material for EDLCs. Activating these organic pigments with varying potassium hydroxide ratios allowed the fabrication of activated carbon with a higher yield than that for conventional activated carbon. Furthermore, it was confirmed that activated carbon with a very high specific surface area can be efficiently fabricated, demonstrating a remarkable potential in various application fields. Notably, this activated carbon exhibited an impressive maximum specific surface area and a total pore volume of 3,935 m2/ g and 2.324 cm3/ g, respectively, showcasing its substantial surface area and distinctive porous characteristics. Additionally, the Langmuir and Freundlich isotherm models were employed to examine the TC adsorption on the activated carbon, with the Langmuir model demonstrating superior suitability than the Freundlich model. Furthermore, the electrochemical performance of an activated carbon-based electrode for EDLCs was rigorously evaluated through cyclic voltammetry. The specific capacitance exhibited a considerable increase in proportion to the expanding specific surface area of the activated carbon.

Electrochemical and physical adsorption properties of activated carbon with ultrahigh specific surface area using 2,9-dimethyl quinacridone (2,9-DMQA)
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Preparation of pigment-based activated carbon
        2.3 Characterization of the pigment-based activated carbon
        2.4 TC adsorption experiments
        2.5 Fabrication of activated carbon electrodes and their electrochemical properties
    3 Results and discussion
        3.1 Morphology and pore structure of the pigment-based activated carbon
        3.2 Adsorption performance analysis of the pigment-based activated carbon
        3.3 Electrochemical characteristics of the pigment-based activated carbon electrodes
    4 Conclusions
    References

• Taemin Ahn(Department of Textile System Engineering, College of Engineering, Kyungpook University, Daegu 41566, Korea)
• Woong Kwon(Department of Textile System Engineering, College of Engineering, Kyungpook University, Daegu 41566, Korea)
• Byong Chol Bai(Division of Energy Engineering, Daejin University, Pocheon 1007, Korea) Corresponding author
• Euigyung Jeong(Department of Textile System Engineering, College of Engineering, Kyungpook University, Daegu 41566, Korea)