CeO2 thin film as a low-temperature formaldehyde sensor in mixed vapour environment

Abstract

Nanostructured cerium oxide thin film was deposited onto the glass substrate under optimized condition using spray-pyrolysis technique. X-ray diffraction result indicates polycrystalline nature of the film with fluorite-type face-centered-cubic structure. The atomic force micrograph indicates the presence of nanocrystallites over the film surface. The vapour sensing characteristics of the annealed film were studied by chemiresistive method for various concentrations of formaldehyde vapour at room temperature (~ 30 °C). For 0⋅5 ppm of formaldehyde vapour, the film shows a response and recovery time of 36 and 1 s, respectively. The vapour sensing properties of the cerium oxide film in mixed environment were studied and reported.

Cerium Oxide-Tungsten Oxide Core-Shell Nanowire-Based Microsensors Sensitive to Acetone

“…Further tests, also performed on tungsten oxide, modified with TiO 2 [31] or Si [32] show the functionality of the sensors at similar (30 ppm) or lower (100–600 ppb) acetone concentrations, respectively, although requiring higher operating temperatures (400–500 °C), than those needed in this work. On the other hand, the use of cerium oxide as the gas sensitive element has been rarely reported in the literature, with the performance of this material having indicated the potential for sensing VOCs including acetone [33,34]. In general, the responses of the above mentioned non-miniaturized acetone sensors in the literature [30,31,32,33,34] are in the same order of magnitude than our micromachined sensors based on the cerium oxide-tungsten oxide core-shell wires, which suggests the viability of sensor miniaturization without losing the sensitivity of the system when optimizing the sensitive material.…”

“…On the other hand, the use of cerium oxide as the gas sensitive element has been rarely reported in the literature, with the performance of this material having indicated the potential for sensing VOCs including acetone [33,34]. In general, the responses of the above mentioned non-miniaturized acetone sensors in the literature [30,31,32,33,34] are in the same order of magnitude than our micromachined sensors based on the cerium oxide-tungsten oxide core-shell wires, which suggests the viability of sensor miniaturization without losing the sensitivity of the system when optimizing the sensitive material. In addition, the good reproducibility of the responses during the testing period and the analysis (SEM, XRD) of the samples after the gas sensing experiments (which showed unchanged properties of the material with respect to the properties recorded initially) indicated a good stability of the sensors.…”

Effect of Oxygen Sputter Pressure on the Structural, Morphological and Optical Properties of ZnO Thin Films for Gas Sensing Application

“…The vapour sensing properties of the film have been studied using home-build test chamber of 1.5 L capacity [ 36 ]. Before sensing studies, the film was conditioned at 300 °C for 24 h to remove undesirable pre-adsorbed organic and water molecules.…”

Design of an ultra-sensitive gold nanorod colorimetric sensor and its application based on formaldehyde reducing Ag+

“…Thus, this method could be applied to determination of HCHO content in water samples and prediction of formaldehyde pollution. 17 1.5-300 (Â10 À6 ) Y ¼ 2.5262 + 4.6 Â 10 À5 X 0.9978 5.4 Â 10 À7 Gas sensor 18 15-185 (Â10 À6 ) Y ¼ 0.227 + 1.72 Â 10 À7 X 0.9918 5 Â 10 À6 Low-temperature sensor 19 1-5 (Â10 À6 ) 0.9998 1 Â 10 À6 Miniature room temperature sensor 20 1-30 (Â10 À6 ) 1 Â 10 À6 Seen from Table 4, the F was 1.1 and 2.4 for the three water sample, respectively, indicating that there was no signicant differences between S 1 and S 2 , and the corresponding t was 1.7 and 0.8, respectively, indicating that there was also no signicant differences between X 1 and X 2 . Obviously, the results of the proposed sensor were tallied well with those obtained by SSRTP, indicating that the designed sensor was sensitive, accurate and reliable to the detection and monitor of HCHO in the environment.…”

“…Many analytical methods have been reported for the determination of HCHO in various samples, including spectrophotometry, 5 uorimetry, 6 capillary chromatography, 7 ow injection catalytic method, 8 voltammetry, 9 solid substrate-room temperature phosphorimetry (SSRTP), 10 resonance uorescence spectrometry, 11 chemiluminescence, 12 gas chromatography (GC), 13 catalytic uorescence method, 14 SERS, 15 HPLC, 16 conductometric biosensor, 17 gas sensor, 18 low-temperature sensor 19 and miniature room temperature sensor. 20 However, these methods are either expensive, labor intensive or time consuming, making them unsuitable for on-site analysis.…”