Oxygen interference mechanism of platinum–FET hydrogen gas sensor

This paper reports the effect of oxygen in air on a Pt–FET hydrogen sensor. The output voltage change of the Pt–FET had good linearity to the logarithm of hydrogen concentration in nitrogen. The slope of the linear curve is −26.4 mV/decade, which is close to the calculated value of the Nernstian slope. This indicates the response mechanism of the Pt–FET sensor is based on the catalytic reaction on the Pt surface. However, the output voltage change of the Pt–FET was not proportional to the logarithm of hydrogen concentration in air due to adsorbed oxygen on the Pt surface. This indicates the water formation for the reaction of hydrogen and oxygen on the Pt surface is the main hydrogen response mechanism in air.