Two-dimensional (2D) transition metal dichalcogenides (TMDs) hold great promise for room temperature (RT) NO₂ sensors. However, the exposure of the edges of TMDs with high adsorption capability and electronic activity remains a great obstacle to achieve high sensor sensitivity. Herein, we demonstrate a high-performance RT NO₂ gas sensor based on WS₂ nanosheets/carbon nanofibers (CNFs) composite with abundant intentionally exposed WS₂ edges. Few-layer WS₂ nanosheets are anchored on CNFs through a hydrothermal process. The approach permits to achieve a coating presenting an optimized active surface area and accessibility of the sensing layers. The exposure of WS₂ edges remarkably improves the sensing properties. Consequently, the WS₂@CNFs composite exhibits excellent selectivity to NO₂ at RT with improved response and much lower detection limit in comparison to the WS₂ and CNFs counterparts. Density functional theory (DFT) calculations verify a surprisingly strong NO₂ adsorption on WS₂ edge sites (adsorption energy 3.40 eV) with a partial charge transfer of 0.394e, while a week adsorption on the basal surface of WS₂ (adsorption energy 0.25 eV) with a partial charge transfer of 0.171e. The strategy proposed herein will be instructive to the design of efficient material structures for low-power NO₂ sensors with optimized performances.

二维（2D）过渡金属二硫化碳（TMD）对于室温（RT）NO ₂传感器具有广阔的前景。然而，具有高吸附能力和电子活性的TMD边缘暴露仍然是实现高传感器灵敏度的巨大障碍。本文中，我们演示了一种基于WS ₂纳米片/碳纳米纤维（CNF）复合材料的高性能RT NO ₂气体传感器，其中有大量故意暴露的WS ₂边缘。几层WS ₂纳米片通过水热过程固定在CNF上。该方法允许获得呈现最佳的活性表面积和感测层可及性的涂层。WS ₂的曝光边缘显着改善了感测特性。因此，与WS ₂和CNFs对应物相比，WS ₂ @CNFs复合物在RT下对NO ₂表现出优异的选择性，并具有改善的响应性和更低的检测限。密度泛函理论（DFT）计算验证了WS ₂边缘位点上的NO ₂吸附能力出乎意料的强（吸附能3.40 eV），部分电荷转移为0.394e，而在WS ₂的基面上吸附了一周（吸附能0.25 eV） ），且部分电荷转移为0.171e。本文提出的策略将对设计低功率NO ₂的有效材料结构具有指导意义 具有优化性能的传感器。