Inherently Flexible Sn _{1– <i>x</i>} Sb _<i>x</i> O ₂ Solid Solution Nanofibers with Light-Driven Plasmon for Wearable Room-Temperature Gas Sensors

The rapid advancement of the Internet of Things technology has driven a significant demand for wearable and portable gas sensors. However, the inherent brittleness and rigidity of inorganic resistive metal oxide semiconductors (MOSs) limit their flexibility in wearable sensor applications. Herein, for the first time, we present a novel approach to address these limitations by developing inherently flexible gas sensors using electrospun Sn_1-<i>x</i>Sb_<i>x</i>O₂ solid solution nanofibers. The self-supported nanofiber membranes exhibit remarkable inherent flexibility, which can be attributed to their ultrafine grain size and hybrid amorphous-crystalline structure that effectively mitigates the formation of macroscopic cracks within the Sn₁_-<i>x</i>Sb_<i>x</i>O₂ nanofibers. Furthermore, these Sn₁_-<i>x</i>Sb_<i>x</i>O₂ solid solution nanofibers demonstrate pronounced surface plasmon resonance absorption in the visible-light spectrum, enabling visible-light-driven room-temperature detection of nitrogen dioxide (NO₂) at parts-per-billion (ppb) levels, which enhances their applicability for wearable devices. Additionally, the unique nanofiber network structure significantly improves air permeability, thereby facilitating gas sensing reactions while enhancing user comfort. These findings pave the way for the development of wearable real-time gas monitoring technologies, addressing critical challenges within the gas sensing field.