Rapid and ultrasensitive detection of toxic gases at room temperature is highly desired in health protection but presents grand challenges in the sensing materials reported so far. Here, we present a gas sensor based on novel zero dimensional (0D)/two dimensional (2D) indium oxide (In₂O₃)/titanium carbide (Ti₃C₂T_x) Schottky heterostructures with a high surface area and rich oxygen vacancies for parts per billion (ppb) level nitrogen dioxide (NO₂) detection at room temperature. The In₂O₃/Ti₃C₂T_x gas sensor exhibits a fast response time (4 s), good response (193.45% to 250 ppb NO₂), high selectivity, and excellent cycling stability. The rich surface oxygen vacancies play the role of active sites for the adsorption of NO₂ molecules, and the Schottky junctions effectively adjust the charge-transfer behavior through the conduction tunnel in the sensing material. Furthermore, In₂O₃ nanoparticles almost fully cover the Ti₃C₂T_x nanosheets which can avoid the oxidation of Ti₃C₂T_x, thus contributing to the good cycling stability of the sensing materials. This work sheds light on the sensing mechanism of heterojunction nanostructures and provides an efficient pathway to construct high-performance gas sensors through the rational design of active sites.

中文翻译：

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介孔封装 In2O3/Ti3C2TX 肖特基异质结可在室温下快速检测 ppb 级 NO2

在健康保护方面非常需要在室温下快速、超灵敏地检测有毒气体，但这对迄今为止报道的传感材料提出了巨大的挑战。在这里，我们提出了一种基于新颖的零维（0D）/二维（2D）氧化铟（In ₂ O ₃）/碳化钛（Ti ₃ C ₂ T _x）肖特基异质结构的气体传感器，具有高表面积和富氧室温下十亿分之一 (ppb) 级二氧化氮 (NO _{2 ) 检测的空缺。}In ₂ O ₃ /Ti ₃ C ₂ T _x气体传感器具有快速响应时间（4 s）、良好响应（193.45%至250 ppb NO ₂）、高选择性和出色的循环稳定性。丰富的表面氧空位起到吸附NO ₂分子的活性位点的作用，肖特基结通过传感材料中的传导隧道有效地调节电荷转移行为。此外，In ₂ O ₃纳米颗粒几乎完全覆盖Ti ₃ C ₂ T _x纳米片，可以避免Ti ₃ C ₂ T _x的氧化，从而有助于传感材料良好的循环稳定性。这项工作揭示了异质结纳米结构的传感机制，并为通过合理设计活性位点构建高性能气体传感器提供了有效途径。