Three-dimensional (3D) carbon nanotube-based porous networks have received considerable attention as active nanomaterials for flexible/wearable sensor applications due to their excellent conductivity and mechanical flexibility. Herein, ultralight, biocompatible, and conductive SWCNT/tannic acid (TA) and Mg 2+ /SWCNT/TA aerogels have been facilely fabricated using TA as a dispersion reagent and crosslinker and Mg 2+ to introduce a metal−phenolic network. The construction of a SWCNT@ TA core−shell structure and the low CNT concentration of SWCNT/TA 3:3 contribute to a high linear sensitivity of 432 kPa −1 in a wide pressure range (0.014−28 kPa), while Mg 2+ modulation endows Mg 2+ /SWCNT/TA 1:1 with an ultrahigh linear sensitivity of 13662 kPa −1 in a pressure range of 0.014−1.05 kPa. The superior sensing performance of as-prepared aerogels, including high sensitivity, wide working range, low detection limit (14 Pa), and fast stimuli-response (200−300 ms), enables them to detect tiny changes in human biosignals and imperceptible vibration, which show great potential in applications of health monitoring, human− machine interfaces, and various flexible electronics.

Biomass is an abundant, low-cost, renewable, and structurally diverse carbon-rich source, which makes it an intriguing precursor to fabricate diversified carbon materials, whereas it is difficult to control the structure and surface functionality of biomass-derived porous carbons. In this work, a strategy of utilizing in situ-formed FeCl2 as a catalyst, molten salt as a template, NH4Cl as a N source, and a chemical blowing agent to assist in activating, catalyzing, and doping the biomass precursor is proposed to fabricate heteroatom-doped porous carbon NPCFe. The as-prepared NPCFe has a large specific surface area of 1168.5 m2 g–1 with abundant micropores and a high level of N/O-doping content (8.6/7.5 atom %). The NPCFe as an electrode material has a high specific capacitance of 379 F g–1, good rate capability, and excellent cycle stability. The NPCFe-assembled symmetric supercapacitor has a high energy density of 18.9 Wh kg–1 at a power density of 325 W kg–1. This strategy of combining in situ molten salt templating and chemical blowing is promising in preparing high-performance porous carbons for supercapacitor applications.

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