Chemiresistive gas sensors for methane, based on lead sulphide nanoparticles and reduced graphene oxide

Details

Supervisors

Hermans, Sophie ; Hackens, Benoît

Faculty

Faculté des sciences

Degree label

Master [120] en sciences chimiques, à finalité approfondie

Abstract

Nowadays, global warming is a pressing issue that is being intensified by greenhouse gases. Among these gases, methane is the second most abundant anthropogenic gas released after carbon dioxide. Methane is widely used as a fuel in chemical industry due to its favourable ignition properties and high heating value, making it also a suitable choice for residential and commercial heating systems. However, methane poses challenges for detection as it is a low polarizable gas. Additionally, it can react with or absorb ambient moisture and is susceptible to interferences with other gases like VOCs, NO2, and CO. Therefore, there is a growing demand for methane gas sensors that are sensitive, selective, and user-friendly. One potential solution lies in the use of solid-state chemi-resistors made of nanohybrid materials, specifically the promising combination of lead sulphide nanoparticles (NPs) and reduced graphene oxide (rGO). This work focuses on exploring this combination. The objective of this Master's thesis is to develop a sensor that is sensitive, selective, environmentally friendly, and simple to produce. To achieve this goal, the device is constructed using lead sulphide nanoparticles coated onto reduced graphene flakes, which are then deposited onto interdigitated electrodes. When the PbS NPs encounter methane gas molecules, NPs resistance increases, leading to a charge transfer from the NPs to the graphene flakes that are in contact with the interdigitated electrodes. This process generates an easily interpretable electrical signal, providing a readable output.