Agricultural waste buckwheat husk derived bifunctional nitrogen, sulfur and oxygen-co-doped porous carbon for symmetric supercapacitors and capacitive deionization. (25th May 2021)

• Record Type: Journal Article
• Authors: Li, Guanfeng; Yang, Fan; Wu, Lisha; Qian, Lei; Hu, Xiaorong; Wang, Zaimin; Chen, Wen
• Is Part Of: New journal of chemistry. Volume 45:Number 23(2021)
• Page Start: 10432
• Page End: 10447
• Publication Date: 2021-05-25
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d1nj00579k
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : A practical strategy for the value-added utilization of agricultural waste was provide. The buckwheat husk derived N, S, O-co-doped porous carbon was used as bifunctional electrode materials for symmetric supercapacitor and capacitive deionization. Abstract : In electric double layer capacitors (EDLCs), the capacitance is produced by the electrostatic charge separation at the interface between the electrode and the electrolyte. Capacitive deionization (CDI) is a novel desalination technique which shares a similar working principle with EDLCs. Due to their similar working principles, highly efficient electrode materials for EDLCs and CDI have many similarities. In this report, N, S, O-co-doped porous carbon (NSO-PC) were prepared and used as bifunctional materials for EDLCs and CDI using buckwheat husk as a precursor and thiourea as a dopant. The double-edged sword effect of heteroatom doping was discussed in detail. When the ratio of thiourea to buckwheat husk was 2 : 1, the proposed NSO-PC exhibited high surface area, an interconnected micro–mesoporous structure, good EDLCs performance and could be used for constructing a symmetric supercapacitor. The symmetric supercapacitor could be used as an energy storage device for an LED array. The NSO-PC also displayed high electrosorption capacity (12.7 mg g −1 at 1.2 V in 500 mg L −1 NaCl solution), high charge efficiency (higher than 0.9) and good desalination–regeneration performance (the electrosorption capacity retention was 96% after 30 cycles) in CDI application. This study provides a bright way to develop bifunctional electrodes from agricultural waste for symmetric supercapacitors and CDI.