Multifunctional N and O co-doped 3D carbon aerogel as a monolithic electrode for either enzyme immobilization, oxygen reduction and showing supercapacitance. (1st November 2021)

• Record Type: Journal Article
• Authors: Kang, Zepeng; Wang, Yuanming; Yang, Chennan; Xu, Bing; Wang, Lei; Zhu, Zhiguang
• Is Part Of: Electrochimica acta. Volume 394(2021)
• Publication Date: 2021-11-01
• Subjects: Carbon aerogel -- Preoxidation process -- Biofuel cell -- Supercapacitors -- ORR; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139179
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: A novel N and O co-doped 3D carbon aerogels (CAs) with a cross-linked "string-bead" network was prepared by a two-step carbonization technology of preoxidation and carbonization. The peroxidation process could improve the thermostability and heteroatoms content of polymer-derived carbon materials during the carbonization process. The developed network structure could increase the electroconductibility and the nanoscale "bead" could provide more effective electrochemical active sites. Four major reactions were speculated to explain the effect of structural evolution during the preoxidation process on the properties of final products . This composite CAs displayed excellent electrochemical performance in enzymatic biofuel cells, supercapacitors and ORR. Abstract: Herein, a novel N and O co-doped three dimensional (3D) hybrid carbon aerogel (CA) was prepared by a two-step carbonization technology, i.e. preoxidation process (240 °C, air atmosphere) and carbonization process (600∼1000 °C, nitrogen atmosphere). It was found that the peroxidation process could improve the thermostability and heteroatoms content during the carbonization. The obtained CA samples inherited their original morphology of "string-bead" network and had a higher heteroatoms content, while the control samples did not. We focused on the application of this CA in either lactate oxidase-modified, super-capacitive and oxygen reductive electrodes. The fabricated lactate-powered integrated electronic skin could produce a maximum power density of ca. 1.3 mW cm −2, which allowed powering a multiplexed metabolic electronic in situ . The sample of CF-PVA-PANI800 showed the highest specific capacitance of 427.2 F g −1 at a discharge specific current of 0.5 A g −1 . The synergistic effect of the N functionalities endowed the sample of CF-PVA-PANI900 with similar electrocatalytic activity to a 20 wt% commercial Pt/C catalyst for ORR. This fabrication strategy of carbon aerogel may provide a new alternative for preparing more heteroatom-doped 3D carbon materials in future. Graphical abstract: Image, graphical abstract