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

This paper reports the gas sensing properties of CdGa2O4 spinet 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 degrees 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.