Sensitive Carbon Monoxide Gas Sensor Based on Chemiluminescence on Nano-Au/Nd2O3-Ca3Nd2O6: Working Condition Optimization by Response Surface Methodology.

Abstract

An Au/Nd2O3–Ca3Nd2O6 composite was synthesized by the sol–gel and impregnation method. The EDS spectrum and the transmission electron microscopy image showed that Au atoms are uniformly distributed on the surface of Nd2O3–Ca3Nd2O6 with a size of less than 50 nm. A sensitive carbon monoxide gas sensor based on chemiluminescence at a temperature lower than 200 °C was reported. There is a good linear relationship between the chemiluminescence intensity and the concentration of carbon monoxide in the range of 0.6–125 mg/m3. The detection limit (3σ) is 0.2 mg/m3. The working conditions optimized by the response surface methodology were an analytical wavelength of 620.90 nm, a reaction temperature of 131.63 °C, and a carrier-gas velocity of 105.46 mL/min. The sensitivity of the method can be increased by 4.5% under the optimized working conditions, which is especially important for the determination of trace substances. The carbon monoxide sensor demonstrated in this paper can be used for practical applications. The optimization method is universal for many multiparameter processes.