Liquefied petroleum gas (LPG), a mixture of different hydrocarbons, is a highly inflammable and explosive gas that is harmful to the environment and human health. Thus, it is imperative to fabricate LPG sensors with higher sensitivity, selectivity, stability, and minimal power consumption, functioning at low temperatures. The current study reports on the monitoring and detection of LPG at low functional temperatures using Co3O4-loaded on rGO (rGO-Co) prepared using the hydrothermal method. The microstructural properties of the materials were investigated in detail. The rGO-Co (80 wt%) sensor showed outstanding sensitivity (0.00364 ppm−1) and selectivity toward LPG, as well as a limit of detection of 1 ppm at a temperature of 125 °C. The sensing mechanism showed that an even distribution of Co3O4 throughout the rGO layers, serving as efficient sites for the adsorption and desorption of LPG molecules, was associated with enhanced gas-sensing capabilities. Furthermore, the response to LPG detection was significantly influenced by the combination of the finite spherical nanoparticles with increased pore sizes between them and reduced energy band gaps. Thus, the novel improvement of the sensor towards LPG detection was linked to the ohmic connection formed between rGO and Co3O4 forming a p-p heterojunction at the interface. Additionally, the coupling of Co-O-C bonds validated by high-temperature X-ray diffraction and X-ray photoelectron spectroscopy provided extra active sites from Co3+ for effective LPG adsorption. The sensing mechanism induced by the loading of Co3O4 on the rGO surface was also deliberated.

中文翻译：

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还原氧化石墨烯层对 Co3O4/rGO 纳米复合材料液化石油气 (LPG) 传感特性的影响


液化石油气（LPG）是不同碳氢化合物的混合物，是一种高度易燃易爆的气体，对环境和人体健康有害。因此，必须制造具有更高灵敏度、选择性、稳定性和最小功耗、在低温下工作的液化石油气传感器。目前的研究报告了使用水热法制备的 rGO (rGO-Co) 上负载 Co3O4 在低功能温度下监测和检测 LPG。对材料的微观结构性能进行了详细研究。 rGO-Co (80 wt%) 传感器对 LPG 表现出出色的灵敏度 (0.00364 ppm−1) 和选择性，以及在 125 °C 温度下的检测限为 1 ppm。传感机制表明，Co3O4 均匀分布在整个 rGO 层中，作为 LPG 分子吸附和解吸的有效位点，与增强的气体传感能力有关。此外，有限球形纳米粒子之间的孔径增大和能带间隙减小的组合显着影响了对液化石油气检测的响应。因此，传感器在 LPG 检测方面的新颖改进与 rGO 和 Co3O4 之间形成的欧姆连接有关，在界面处形成 pp 异质结。此外，通过高温 X 射线衍射和 X 射线光电子能谱验证的 Co-OC 键耦合为 Co3+ 提供了额外的活性位点，可有效吸附 LPG。还探讨了在 rGO 表面负载 Co3O4 引起的传感机制。