Balasubramani V, Sureshkumar S, Rao T Subba, Sridhar T M
Department of Analytical Chemistry, University of Madras, Guindy Campus, Chennai 600025, India.
Department of Chemistry, Rajalakshmi Engineering College, Chennai 602105, India.
ACS Omega. 2019 Jun 7;4(6):9976-9982. doi: 10.1021/acsomega.9b00754. eCollection 2019 Jun 30.
Electrochemical impedance spectroscopy (EIS) has been applied to measure the HS gas response of the sensor fabricated on reduced graphene oxide (rGO)-incorporated nano-zinc oxide (n-ZnO) composites. These nanocomposites were prepared by a facile one-step solution route at room temperature. The structural, surface morphological, and elemental analyses of the composite material have been investigated. EIS was carried out to study the HS gas-sensing properties of fabricated sensors. The developed sensor showed an optimal HS gas response to various concentrations ranging from 2 to 100 ppm at 90 °C. The HS gas-sensing performances of pure n-ZnO and various concentrations of rGO-incorporated n-ZnO were evaluated. The HS gas-sensing results showed that n-ZnO/rGO composites exhibited high response when compared to pure n-ZnO. The enhanced HS response was speculated to be ascribed due to two factors. First, rGO creates reactive sites for HS molecule adsorption. Second, rGO has great electrical conductivity compared to n-ZnO that enables the active transport of electrons from HS gas on interaction with the sensing layer, resulting in enhanced gas response at 90 °C temperatures.
电化学阻抗谱（EIS）已被用于测量基于还原氧化石墨烯（rGO）复合纳米氧化锌（n-ZnO）制备的传感器对硫化氢气体的响应。这些纳米复合材料是在室温下通过简便的一步溶液法制备的。对复合材料进行了结构、表面形态和元素分析。采用EIS研究了所制备传感器的硫化氢气敏特性。所开发的传感器在90℃时对2至100 ppm的各种浓度硫化氢气体表现出最佳响应。评估了纯n-ZnO以及不同浓度rGO复合n-ZnO的硫化氢气敏性能。硫化氢气敏结果表明，与纯n-ZnO相比，n-ZnO/rGO复合材料表现出高响应。推测增强的硫化氢响应归因于两个因素。第一，rGO为硫化氢分子吸附创造了活性位点。第二，与n-ZnO相比，rGO具有良好的导电性，使得硫化氢气体与传感层相互作用时电子能够有效传输，从而在90℃温度下增强了气体响应。
