Large optical CO sensitivity of NO2-pretreated AuNiO composite films

Abstract

Abstract Gold-nickel oxide (AuNiO) composite films were prepared by sputter-deposition of fine Au particles on a glass plate substrate followed by pyrolysis of spin-coated nickel 2-ethylhexanoate. They showed reversible changes in visible-near IR light absorption due to CO in air. The pretreatment of the AuNiO composite films with NO2 appreciably enhanced the CO-sensitive absorbance change, allowing optical CO detection over a wide concentration range of 50-10 000 ppm.