Pt-activated Ce4La6O17 nanocomposites for formaldehyde and carbon monoxide sensor at low operating temperature

In this paper, a cataluminescence (CTL) type formaldehyde (HCHO) and carbon monoxide (CO) gas sensor based on their cross sensibility on platinum (Pt) activated Ce₄La₆O₁₇ nanocomposites at lower operating temperature than 150 °C was reported. The Ce₄La₆O₁₇ nanocomposites were synthesized via sol-gel method. Pt was added into the composites by dipping the composites into the aqueous solution of chloroplatinic acid and calcined at 300 °C. The EDS spectrum and TEM images showed the constituents, distribution and particle size of the obtained composites. The sensing conditions were optimized, and the sensing properties were characterized. The linear ranges of CTL intensity versus analyte concentration was 0.2–54.5 ppm for HCHO and 1.2–67.0 ppm for CO. The limits of detection were 0.04 ppm for HCHO and 0.6 ppm for CO. The recoveries of 10 testing standard samples was 96.6%~103.2% for HCHO and 97.6%~103.5% for CO. These results indicated that nano-Pt/Ce₄La₆O₁₇ would be a good candidate for fabricating practical CTL gas sensor for HCHO and CO.