The design of a sensing material for detecting isopropanol gas with low operating temperature is extremely important for miniaturization and wearability of gas sensors. Herein, a novel gas sensor based on SnO2-Carbon nanosphere heterojunctions decorated with Ag nanoparticles (SCA) was fabricated and its gas sensing performance was evaluated and compared systematically. The measurement results indicated that the sensing performance was influenced by the ratio of Sn/C and the length of Ag plating, and the SCA sensor provided the best response. For 100 ppm isopropanol at 100 °C, the SCA sensor exhibited a response value of 50.51, a response time of 7 s and a recovery time of 60 s. The enhanced sensing performance and reduced operating temperature of the SCA could be attributed to the synergistic effect of the SnO2-Carbon nanosphere heterojunctions and the significant catalytic performance of the decorated Ag nanoparticles. In addition, the density functional theory calculation method based on the first-principles theory was used to study the adsorption performance and electronic behavior, as well asthe influence of Ag decoration on SnO2 for isopropanol detection. The calculated results were consistent with the experimental results.

中文翻译：

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用 Ag 修饰的高效 SnO2-碳纳米球异质结，用于在低温下检测异丙醇


用于检测低温异丙醇气体的传感材料的设计对于气体传感器的小型化和耐磨性极为重要。在此，制备了一种基于 SnO2-碳纳米球异质结的新型气体传感器，并对其气体传感性能进行了系统评价和比较。测量结果表明，传感性能受 Sn/C 比值和 Ag 镀层长度的影响，SCA 传感器提供最佳响应。对于 100 °C 下 100 ppm 异丙醇，SCA 传感器的响应值为 50.51，响应时间为 7 s，恢复时间为 60 s。SCA 的传感性能增强和工作温度降低可归因于 SnO2-Carbon 纳米球异质结的协同效应和修饰的 Ag 纳米颗粒的显着催化性能。此外，采用基于第一性原理理论的密度泛函理论计算方法，研究了异丙醇检测的吸附性能和电子行为，以及 Ag 修饰对 SnO2 的影响。计算结果与实验结果一致。