Ke Xu,Ziwang Kan,Feiyu Zhang,Yuan Qu,Siqi Li,Song Liu
Ethanol gas sensing has been attracting more and more attention due to its significance, such as human health care, and detection in drunk driving. However, the low sensitivity, the high limit of detection and the long response time restrain its further application development. Here we report SnO 2 nanomaterials with well-controlled hollow multi-shelled structure as an efficient ethanol gas sensing. The shell number was tuned by the concentration of the precursor. Among, the double-shell SnO 2 nanomaterials (SnO 2 -D) exhibited the best selectivity towards ethanol, reaching 22.5 of R g /R a ratio. Moreover, the 1 ppm ethanol was even detected, the R g /R a ratio being 1.37. The response time to 100 ppm ethanol was only 2 s. Furthermore, the SnO 2 -D maintained the same performance after 21 days of continuous response to 100 ppm ethanol. Based on experiments and in situ FTIR, the outstanding sensing performance is attributed to the excellent spatial confinement and large active surface of the double-shell that combine the enhanced gas adsorption, and increase conductive electrons.
Dongmin An,Nan Liu,Hongfei Zhang,Qingfeng Sun,Cong Li,Yan Li,Qinglei Zhang,Yuqing Lu
A series of In 2 O 3 -SnO 2 nanocomposites were synthesized with a facile hydrothermal co-precipitation method and calcination after-treatment at 400 °C. The crystal phase structure, morphology, and elemental composition were characterized by X-ray powder diffraction and field emission scanning electron microscopy with energy dispersive spectroscopy. In 2 O 3 -SnO 2 nanocomposite-based gas sensors were fabricated, and their potential applications were assessed by testing gas-sensing properties systematically. The results exhibited that a small amount of In 2 O 3 dopant improved the dispersion and increased the specific surface area of SnO 2 nanomaterials. Besides, the gas response towards n-butanol gas was promoted and the working temperature was decreased by doping In 2 O 3 . In particular, the 1.5 %In 2 O 3 -SnO 2 nanocomposites-based sensor showed an excellent response of 76.5 towards 50 ppm n-butanol gas at 140 °C. The binding energies of the Sn 3d in nanocomposites varied with the changed doping dosage of In through XPS analysis. The enhanced n-butanol sensing performance of the fabricated In 2 O 3 -SnO 2 sensors at low operating temperature may be due to a synergistic effect between In 2 O 3 and SnO 2 .
Yingyue Wang,Jinyang Huang,Wansheng Tang,Mengying Long,Zongwei Zhang,Hongli Liu,Dongmin An
In this work, an uncomplicated solvothermal method was used to synthesize NiO-SnO 2 gas sensing materials derived from bimetallic MOFs. The influence of MOF derived NiO-SnO 2 with different amount of Ni on the gas sensing performance of triethylamine (TEA) was systematically evaluated. The results showed that the MOF derived 0.5 mol% NiO-SnO 2 based gas sensor exhibited the best gas sensing performance. The response to TEA gas of the sensor reached 124.5 to 50 ppm at 170 °C, which was 1.5 times that of SnO 2 sensor (83). Compared with SnO 2 sensor at 190 °C, its operating temperature was reduced by 20 °C. Moreover, the MOF derived 0.5 mol% NiO-SnO 2 sensor also performed outstanding selectivity towards TEA, with a response that is 3.1–49.8 times higher than other target gases. The MOF derived NiO-SnO 2 nanomaterials were also conducted X-ray photoelectron spectroscopy and UV–visible absorption spectra analysis. The results demonstrated that an increase in specific surface area, abundant oxygen vacancies, a decrease in forbidden bandwidth, and the formation of p-n heterojunctions were significant factors in improving the gas sensing performance of MOF derived NiO-SnO 2 nanomaterials.
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