Enhancement in the optical CO sensitivity of NiO film by the deposition of ultrafine gold particles

In the presence of reducing gases thin NiO films show reversible changes for visible–near-IR light absorption, a phenomenon which can be applied to the optical detection of CO in air. The deposition of highly dispersed Au on NiO films by a deposition–precipitation method significantly enhances the optical sensitivity and the response rate, allowing CO detection under a substantially lowered operating temperature.