Copper oxide and scandium oxide were mixed with p-type semiconducting
nickel oxide and its NO2 sensing performance was investigated. By mixi
ng copper oxide with nickel oxide, the response of the oxide for NO2 w
as improved. Further Sc2O3 mixing with nickel copper oxide greatly enh
anced the sensing performance. Especially, the addition of scandium ox
ide into nickel copper oxide was considerably effective to sense only
NO2 in the nitrogen oxides existing atmosphere.