Multifunctional N and O co-doped 3D carbon aerogel as a monolithic electrode for either enzyme immobilization, oxygen reduction and showing supercapacitance

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 degrees C, air atmosphere) and carbonization process (600 similar to 1000 degrees 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-PANI(800) 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-PANI(900) 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. (C) 2021 Elsevier Ltd. All rights reserved.