Jang, Ji Soo Yu, Hayoung Choi, Seon-Jin Koo, Won-Tae Lee, Jiyoung Kim, Dong-Ha Kang, Joon-Young Jeong, Yong Jin Jeong, Hyeonsu Kim, Il-Doo 2024-01-19T20:33:45Z 2024-01-19T20:33:45Z 2021-09-02 2019-03 1944-8244 https://pubs.kist.re.kr/handle/201004/120310 The development of freestanding fiber-type chemiresistors, having high integration ability with various portable electronics including smart clothing systems, is highly demanding for the next-generation wearable sensing platforms. However, critical challenges stemming from the irreversible chemical sensing kinetics and weak reliability of the free-standing fiber-type chemiresistor hinder their practical use. In this work, for the first time, we report on the potential suitability of the freestanding and ultraporous reduced graphene oxide fiber functionalized with WO3 nanorods (porous WO3 NRs-RGO composite fiber) as a sensitive nitrogen dioxide (NO2) detector. By employing a tunicate cellulose nanofiber (TCNF), which is a unique animal-type cellulose, the numerous mesopores are formed on a wet-spun TCNF-GO composite fiber, unlike a bare GO fiber with dense surface structure. More interestingly, due to the superior wettability of TCNF, the aqueous tungsten precursor is uniformly adsorbed on an ultraporous TCNF-GO fiber, and subsequent heat treatment results in the thermal reduction of a TCNF-GO fiber and hierarchical growth of WO3 NRs perpendicular to the porous RGO fiber (porous WO3 NRs-RGO fiber). The freestanding porous WO3 NRs-RGO fiber shows a notable response to 1 ppm NO2. Furthermore, we successfully demonstrate reversible NO2 sensing characteristics of the porous WO3 NRs-RGO fiber, which is integrated on a wrist-type wearable sensing device. English American Chemical Society Heterogeneous Metal Oxide-Graphene Thorn-Bush Single Fiber as a Freestanding Chemiresistor Article 10.1021/acsami.8b22015 1 ACS Applied Materials & Interfaces, v.11, no.10, pp.10208 - 10217 ACS Applied Materials & Interfaces 11 10 10208 10217 N scie scopus 000461538000061 2-s2.0-85062495485 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article LIQUID-CRYSTALS CELLULOSE FILM TRANSITION NANOTUBES MEMBRANES CATALYSTS AREA porous graphene fiber liquid crystal tunicate nitrogen dioxide gas sensor