In the current study, a chemiresistive SO₂ sensor based on a composite of reduced graphene oxide (rGO) and 5, 10, 15, 20-tetra-p-tolyl-21H, 23H-porphine (TPTP) was developed and extensively studied. Improved Hummers methods were used to synthesize graphene oxide (GO), and a thermally heating bottom-up approach was used to reduce GO to rGO. Gold electrodes were thermally coated on the transparent sheet using a thermal evaporator. The composite of rGO/TPTP was synthesized using a simple chemical method. Structural, morphological, spectroscopic, electrical, and optical studies were carried out using X-ray diffraction, atomic force microscopy, field emission scanning electron microscopy, Fourier-transfer infrared spectroscopy, Raman spectroscopy, current–voltage, and UV–vis spectroscopy, respectively. The sensing response of rGO/TPTP for various concentrations of sulfur dioxide (SO₂) was investigated in chemiresistive modality. The rGO/TPTP composite chemiresistive sensor displayed exceptional performance, with a consistent response spanning 1 ppm to 10 ppm. It exhibited outstanding repeatability, linearity, stability, and boasted an impressive limit of detection (LOD) of 1 ppm. This LOD is significantly lower than the recommended permissible exposure limit (PEL) of 5 ppm set by OSHA (Occupational Safety and Health Administration), USA. The sensor based on the rGO/TPTP composite exhibited a very fast response and recovery time of 33 s. and 27 s. respectively.

Graphical abstract

中文翻译：

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还原氧化石墨烯 (rGO) 和 5, 10, 15, 20-四对甲苯基-21H, 23H-卟吩 (TPTP) 复合材料：高度可重复性的化学电阻式 SO2 传感器

在当前的研究中，开发了一种基于还原氧化石墨烯（rGO）和5,10,15,20-四对甲苯基-21 H , 23 H-卟啉（TPTP）复合材料的化学电阻式SO ₂传感器并得到广泛应用研究过。采用改进的 Hummers 方法合成氧化石墨烯 (GO)，并采用热加热自下而上的方法将 GO 还原为 rGO。使用热蒸发器将金电极热涂覆在透明片上。采用简单的化学方法合成了rGO/TPTP复合材料。分别使用 X 射线衍射、原子力显微镜、场发射扫描电子显微镜、傅立叶转移红外光谱、拉曼光谱、电流电压和紫外可见光谱进行结构、形态、光谱、电学和光学研究。以化学电阻方式研究了rGO/TPTP 对不同浓度二氧化硫 (SO _{2 ) 的传感响应。}rGO/TPTP 复合化学电阻传感器表现出卓越的性能，在 1 ppm 至 10 ppm 范围内具有一致的响应。它表现出出色的重复性、线性度、稳定性，并拥有令人印象深刻的 1 ppm 检测限 (LOD)。该 LOD 显着低于美国 OSHA（职业安全与健康管理局）规定的建议允许暴露限值 (PEL) 5 ppm。基于 rGO/TPTP 复合材料的传感器表现出非常快的响应和 33 秒的恢复时间。和 27 秒。分别。

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