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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 Co 3 O 4 -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 Co 3 O 4 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 Co 3 O 4 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 Co 3+ for effective LPG adsorption. The sensing mechanism induced by the loading of Co 3 O 4 on the rGO surface was also deliberated. • Co3O4-loaded onto rGO (rGO-Co) at different weight% was prepared using the microwave-assisted hydrothermal method. • The 80 wt% rGO-Co showed superior sensitivity towards 1000 ppm LPG at 125℃. • The sensor showed theoretical LoD of 1 ppm and sensitivity of 0.00364 ppm-1 • rGO-Co based sensor showed exceptional long-term stability over 5 months.
Tladi et al. (Wed,) studied this question.