Coconut shell-derived activated carbon and carbon nanotubes composite: a promising candidate for capacitive deionization electrode

• Published in: Synthetic metals Vol. 265; p. 116415
• Main Authors: Huynh, Le Thanh Nguyen, Pham, Thi Nam, Nguyen, Thai Hoang, Le, Viet Hai, Nguyen, Thi Thom, Nguyen, Thi Diem Kieu, Tran, Thanh Nhut, Ho, Pham Anh Vu, Co, Thanh Thien, Nguyen, Thi Thu Trang, Vo, Thi Kieu Anh, Nguyen, Trung Huy, Vu, Thi Thu, Luong, Viet Mui, Uyama, Hiroshi, Pham, Gia Vu, Hoang, Thai, Tran, Dai Lam
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.07.2020; Elsevier BV
• Subjects: AC-CNTs composite; Activated carbon; Activated carbon (AC); Adsorption; Capacitive deionization (CDI); Carbon nanotubes; Coconut shell; Deionization; Desalination; Electrode materials; Electrodes; Energy consumption; AC-CNTs composite; Coconut shell; Activated carbon (AC); Capacitive deionization (CDI); Desalination
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2020.116415

•Controllable and easy to scale up design of innovative composites (from inexpensive coconut shell-derived activated carbon and treated MWCNTs) with improved physico-chemical properties.•The composites exhibit superior capacitance value (90.2 F/g), salt adsorption capacity (SAC) of 14.1 mg/g at 1.0 V and stability (95.7% after 100 cycles at 1.0/0 V).•The composite can be a promising candidate for large scale CDI electrode applications. Aiming at more efficient use of coconut resources to achieve multi-purpose goals, this work proposes an innovative composite for capacitive deionization (CDI) electrode in desalination applications when using coconut shell-derived activated Carbon (AC) as a matrix into which a certain amount of carbon nanotubes (CNTs) is incorporated. The electrochemical studies show that the optimized 9mAC:1CNTs electrode with a surface area of 630 m2/g has a specific capacitance of 90.2 F/g (at scan rate of 20 mV/s), salt adsorption capacity (SAC) of 14.1 mg/g at 1.0 V. SAC value is retained as high as 95.7% after 100 adsorption–desorption cycles at 1.0/0 V, showing a good cyclic stability of the electrode composites. Moreover, a calculated specific energy consumption (SEC) value of 0.312 kW h/m3 was quite low compared with other CDI electrodes reported in literature. Briefly, the present study indicates that AC-CNTs composite can serve as promising CDI electrode materials for desalination application.