Charge transport and degradation phenomena in composites of 2D carbon with nanoscale copper chalcogenides in the presence of carbon dioxide at room temperature for miniaturized gas sensor applications – CO2Dsense

• Applicants: Privatdozent Dr. Thomas Hirsch; Dr. Guenther Ruhl
• Subject Area: Synthesis and Properties of Functional Materials
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 555783035

Gas sensors enable to monitor the chemical environment of humans, which can seriously affect their wellbeing on a short- or long-time or even threaten their survival. One of the most abundant environmental gases is carbon dioxide, which is important for the direct (e.g., indoor air quality) as well as for the global environment (earth atmosphere) of humans. Thus, close meshed monitoring of carbon dioxide concentration is highly desirable for quality of life. Prerequisite for doing this is the availability of affordable sensors, achieved by ease of fabrication and a small form factor. Graphene-based gas sensors offer both and have a big potential as a solution for widespread applications. One, frequently envisioned application would be the integration of gas sensors in mobile phones for indoor air quality monitoring, but their application still suffers from the big form factor of conventional carbon dioxide sensors and issues with the sensor material itself, which so far is limited by instability and poor selectivity, when such a sensor needs to be operated at low power and ambient temperature. This project addresses this challenge by exploring copper oxide nanoparticles on a graphene sheet to enable sensitive and selective carbon dioxide detection at room temperature. The main objectives of this proposal are to investigate a) the controlled deposition of defined copper oxide nanoparticles on defect-free graphene with different methods (pulsed laser deposition, solvent assisted deposition); b) the adsorption and sensing mechanism of carbon dioxide on copper oxide / graphene surfaces by in situ analysis techniques such as Raman microscopy and XPS studies; c) the charge transport and the electrical conduction mechanism of the composite material in presence of different gases; d) the long-term stability of the sensor surface and to understand its degradation mechanisms under ambient conditions. The project is expected to generate a solid scientific basement for the understanding of copper oxide/graphene composite chemiresistive carbon dioxide sensors.

• DFG Programme: Research Grants