The formaldehyde sensing properties of CdGa2O4 prepared by co-precipitation method

• Published in: Sensors and actuators. B, Chemical Chemical, 2021-09, Vol.343, p.129834, Article 129834
• Main Authors: Li, Xue, Zhang, Yin, Bhattacharya, Anish, Chu, Xiangfeng, Liang, Shiming, Zeng, Dawen
• Format: Article
• Language: English
• Subjects: CdGa2O4; Coprecipitation; Formaldehyde; Gas sensor; Gas sensors; High resolution electron microscopy; Microscopy; Morphology; Nanomaterials; Photoelectrons; Roasting; X ray photoelectron spectroscopy
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2021.129834

•The effects of precipitation pH value and calcination temperature on gas sensing properties of CdGa2O4 were investigated.•The sensor device based on CdGa2O4 nanoparticles exhibited excellent selectivity toward formaldehyde vapor at the operating temperature of 150 °C. The ratio of S1 ppm formaldehyde to S1 ppm ethanol was about 4.2.•The detection limit for formaldehyde was about 0.01 ppm.•The long-term stability of the sensor based on CdGa2O4 was thirty days. This paper reports the gas sensing properties of CdGa2O4 spinel oxide-based gas sensors for formaldehyde. CdGa2O4-based nanomaterials were prepared by co-precipitation method followed by calcination at different temperatures for 4 h. The structure, morphology and elemental compositions of the materials were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The effects of precipitation pH value and calcination temperature on gas sensing properties of the obtained materials were investigated. The results showed that the materials prepared under different conditions exhibited good responses to 1 ppm formaldehyde. In addition, the material obtained at co-precipitation pH = 9.00 and calcination at 700 °C for 4 h showed responses of 7.22 and 1.21 to 1 and 0.01 ppm formaldehyde, respectively; the corresponding response-recovery times were 9.6–10.9 s and 5.0−4.3 s, respectively. The results demonstrated that CdGa2O4 is a promising candidate for the detection of formaldehyde at ultralow concentrations.