Investigation of the reaction mechanisms in work function type sensors at room temperature by studies of the cross-sensitivity to oxygen and water: the carbonate–carbon dioxide system

摘要: Abstract Thin films and screen-printed of BaCO3 react to changes CO2 in wet synthetic air at room temperature with a change the work function as measured by Kelvin method. The reaction is due formation hydrogen carbonate ions on surface. In this work, mechanism investigated studying cross-sensitivities oxygen humidity range between 25°C 250°C. At low temperatures 100°C, involves water whereas above 200°C, driven presence oxygen. both cases, can be described terms Nernst equation. low-temperature region, however, (thickness-independent) potential type superimposed (thickness-dependent) capacitance like well-known capacitive sensors.