MoO3/TiO2 and Bi2MoO6 as ammonia sensors

Ammonia sensors based on catalytic oxides such as V2O 5, MoO3 and α, β- and γ-bismuth molybdates have been investigated. MoO3 (15 mo1%) supported on TiO2 and γ-Bi2MoO6 both exhibit satisfactory sensing characteristics for NH3, with a reasonably low working temperature (500-575 K) and a minimum detection limit of 10 ppm. Humidity has no measurable effect on the performance of these materials. ESR studies how the formation of Mo5+ species these oxides on contact with NH3.