A miniature room temperature formaldehyde sensor with high sensitivity and selectivity using CdSO₄ modified ZnO nanoparticles

Abstract

A light activated miniature formaldehyde sensor working at room temperature is fabricated by CdSO4 modified ZnO nanoparticles. The CdSO4 is deposited on the surface of the ZnO nanoparticles as a separated phase rather than doping into the lattice of ZnO. The Cd 2+ and SO4 2on the surface play a synergic effect for the high sensitivity to formaldehyde. The sensor shows high sensitivity to formaldehyde, with detection limit lower than 1 ppm while shows no response to ethanol and very weak response to acetone. With engineering efforts, a highly compact prototype formaldehyde sensor is obtained, which is very convenient for portable formaldehyde specific detection.

Inhibiting the Surface Oxidation of Low-Cadmim-Content ZnS:(Cd,Se) Quantum Dots for Enhancing Application Reliability

“…The chemical shifts of the doped ZnS QDs slightly decrease compared with that of pure ZnS that is ascribed to the introduced Cd and Se. The Cd 3d peaks of H 2 O 2 -treated QD-LSe have a chemical shift +0.6 eV (404.2 → 404.8 eV, 410.9 → 411.5 eV), which also shows the existence of the sulfate phase (Cd 3d 5/2 CdSO 4 , 405.8 eV; Figure c). , In addition, although the Se content is very low (∼0.8%), slight SeO 2 peaks are still observed for both as-prepared QDs and treated ones, showing no significant difference, except the chemical environment of Se in the QDs is slightly changed by H 2 O 2 treatment, as shown by a +0.2 eV shift (53.7 → 53.9 eV; Figure d).…”

“…Figure 4 5c). 53,54 In addition, 6c,d). Since the electronegativities of Zn, Cd, S, and Se are rather similar (Zn, 1.6; Cd, 1.7; S, 2.5; Se, 2.4), the decreased chemical shift may be connected to less surface oxidization of QD-HSe, where the surface environment would affect the core properties.…”

Biomorphic CdS/Cd Photocatalyst Derived from Butterfly Wing for Efficient Hydrogen Evolution Reaction

“…[ 13 ] Correspondingly, the spectra of Cd 3d, S 2p peaks of BW@SS were similar to those of SS powder with a slight shift to lower binding energies, demonstrating the similar chemical state of S element surrounded by Cd. [ 41,42 ] Therefore, these results demonstrate a facile route for the fabrication of CdS and Cd 2 SO 4 (OH) 2 composite on the butterfly wing substrate.…”

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.…”