Abstract

Few studies have investigated the electrical and gas sensing properties of reduced graphene oxide/titanium dioxide (rGO/TiO₂) composite thin films by spray pyrolysis technique. In this work, we report the synthesis and systematic investigation of structural, morphological and gas sensing properties of rGO-loaded TiO₂ nanocomposite thin films. The XRD and AFM results suggest that both pure and rGO/TiO₂ nanocomposite showed crystalline with tetragonal anatase phase and individual spherical shaped nanoparticles with average diameter of around 20–30 nm was observed. rGO/TiO₂ nanocomposite showed high surface area (112 m²/g) and larger pores (11.2 nm) than bare TiO₂ (89 m²/g; 32.3 nm). This huge surface area can beneficial for enhancing the gas sensing performance. Resistive type gas sensor set up was constructed and studied the sensing responses towards H₂S and CO₂ gases. The results suggest that the rGO/TiO₂ nanocomposite sensor showed high sensitivity (92%), stability (only loss 3.5%), fast response (30 s) and recovery time (25 s) towards CO₂ gas. The improved gas sensing mechanism of the proposed sensor was discussed in detail.

中文翻译：

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提出了还原型氧化石墨烯/氧化钛（rGO / TiO 2）混合传感器的高性能电阻型H 2 S和CO 2气敏响应

摘要

很少有研究通过喷雾热解技术研究还原氧化石墨烯/二氧化钛（rGO / TiO ₂）复合薄膜的电学和气敏特性。在这项工作中，我们报告了rGO负载的TiO ₂纳米复合薄膜的结构，形态和气体传感特性的合成和系统研究。XRD和AFM结果表明，纯的rGO / TiO ₂和rGO / TiO ₂纳米复合材料均显示具有四方晶锐钛矿相的晶体，并且观察到平均直径约为20–30 nm的单个球形纳米颗粒。rGO / TiO ₂纳米复合材料比裸露的TiO ₂（89 m ²）具有更高的表面积（112 m ² / g）和更大的孔（11.2 nm）。/G; 32.3 nm）。这个巨大的表面积可以有益于增强气体感测性能。建立了电阻式气体传感器，并研究了其对H ₂ S和CO ₂气体的响应。结果表明，rGO / TiO ₂纳米复合传感器显示出对CO ₂气体的高灵敏度（92％），稳定性（仅损失3.5％），快速响应（30 s）和恢复时间（25 s）。详细讨论了所提出的传感器的改进的气体传感机制。