Developing efficient and reliable vapor sensors to detect and monitor 2-Methoxyethanol vapor is crucial to prevent unwanted health issues. Here, we report the preparation of an optimized CdS-TiO₂ nanocomposite with highly reactive and selective Ti-S bonds through the chemical bath deposition of CdS quantum dots on oxygen-deficient TiO₂ nanotubes. Characterization using XRD, FE-SEM, and TEM reveals that the hexagonal CdS quantum dots in the nanocomposite are either distributed on anatase TiO₂ nanotubes or exist as smaller cauliflower-like aggregations compared to pure CdS quantum dots. BET and XPS analyses indicate that, despite having a lower BET specific surface area than pure CdS quantum dots and TiO₂ nanotubes, the CdS-TiO₂ nanocomposite possesses a significant number of unique and highly reactive Ti-S bonds. The nanocomposite-based sensor demonstrates a highly enhanced vapor response (85.20–100 ppm) and improved selectivity towards 2-Methoxyethanol over Ethanol, Ethylene glycol, N,N-Dimethylformamide, Methanol, and Acetone at a lower operating temperature of 360°C. The high sensitivity and selectivity for detecting 2-Methoxyethanol vapor by the CdS-TiO₂ nanocomposite are attributed to the abundant, highly reactive, and selective Ti-S bonds present on the surface of TiO₂ nanotubes and at the CdS-TiO₂ interface, which enhance the surface reactivity of TiO₂ nanotubes and facilitate electron transfer across the CdS/TiO₂ heterojunctions. Overall, the 0D-1D CdS-TiO₂ nanocomposite with abundant Ti-S bonds is a promising candidate for highly sensitive and selective detection of 2-Methoxyethanol vapor.

中文翻译：

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优化的 CdS-TiO2 纳米复合材料，用于 2-甲氧基乙醇蒸气的高灵敏度和选择性检测


开发高效可靠的蒸气传感器来检测和监测 2-甲氧基乙醇蒸气对于防止不必要的健康问题至关重要。在这里，我们报道了通过在缺氧 TiO₂ 纳米管上化学浴沉积 CdS 量子点制备具有高反应性和选择性 Ti-S 键的优化 CdS-TiO₂ 纳米复合材料。使用 XRD、FE-SEM 和 TEM 进行的表征表明，与纯 CdS 量子点相比，纳米复合材料中的六方 CdS 量子点要么分布在锐钛矿 TiO₂ 纳米管上，要么以更小的花椰菜状聚集体存在。BET 和 XPS 分析表明，尽管 CdS-TiO₂ 纳米复合材料的 BET 比表面积低于纯 CdS 量子点和 TiO₂ 纳米管，但具有大量独特且高反应性的 Ti-S 键。在 360°C 的较低工作温度下，基于纳米复合材料的传感器表现出高度增强的蒸汽响应 （85.20–100 ppm），并且对 2-甲氧基乙醇的选择性优于乙醇、乙二醇、N，N-二甲基甲酰胺、甲醇和丙酮。 CdS-TiO₂ 纳米复合材料检测 2-甲氧基乙醇蒸气的高灵敏度和选择性归因于 TiO₂ 纳米管表面和 CdS-TiO₂ 界面上存在的丰富、高反应性和选择性的 Ti-S 键，这增强了 TiO₂ 纳米管的表面反应性并促进了电子跨 CdS/TiO₂ 异质结的转移。总体而言，具有丰富 Ti-S 键的 0D-1D CdS-TiO₂ 纳米复合材料是 2-甲氧基乙醇蒸气高灵敏度和选择性检测的有前途的候选者。