Traditional greenhouse gas monitoring technologies are often costly and complex, leading researchers to explore simpler metal oxide semiconductor (MOS)-based sensors.

Humidity significantly interferes with the performance of metal oxide (MOX) gas sensors, impacting their effectiveness in environmental monitoring and medical diagnostics.

This study investigates the effects of adsorbed water on the conductivity of two materials: pure tin oxide (SnO2) and a tin–titanium–niobium oxide mixture.

Results indicate that (SnTiNb)xO2 sensors exhibit reduced sensitivity to humidity compared to pure tin oxide, making them more suitable for applications where humidity is a critical factor.

Sensing tests revealed that the sensors demonstrated higher sensitivity to methane than to carbon dioxide, with distinct saturation tendencies at increasing methane concentrations.

Experimental analysis conducted at varying temperatures showed that temperature modulates the sensitivity of the sensors to ambient gases.

The research focuses on optimizing sensing properties based on synthesis method, operating temperature, and electrode geometry.

The electrode gap significantly influences sensor performance, with smaller gaps enhancing sensitivity for certain materials.

Powders were deposited on alumina substrates with platinum interdigital electrodes featuring gaps of 200 μm and 100 μm.

Surface area and porosity analysis using N2 adsorption/desorption isotherms showed that the co-precipitation method had a higher surface area and mesoporosity compared to hydrothermal growth.

The co-precipitation method produced uniform quasi-spherical nanoparticles around 6 nm, while the hydrothermal method resulted in larger irregular nanoparticles approximately 42 nm in size.

This research aims to clarify the controversial mechanisms of water surface interactions with these materials, supported by theoretical studies from existing literature.