化学专业外文资料翻译--具有高灵敏度的甲醛气体传感器的制备及其气敏特性(编辑修改稿)

化学专业外文资料翻译--具有高灵敏度的甲醛气体传感器的制备及其气敏特性(编辑修改稿)内容摘要：

fect the state and amount of oxygen species on the surface of sensors, and consequently the performance of the metal oxidebased sensors. Therefore, in order to enhance and improve the gas sensing performances (sensitivity, selectivity, good thermal stability, and lower operating temperature), In2O3 is usually prepared in a nanostructured form and/or doped with suitable noble metals and/or metal oxides [5–11].Asa singleponent oxide, In2O3 is a promising candidate for the detection of oxidizing gases because of its good sensitivity [12]. Thus, when other metal oxides were doped into In2O3, the resulting materials have the potential for tunable sensitivity for different gases [6]. They have been well studied as the sensor material to detect most of the key gases, such as ethanol [5],CO [6,7],NO2 [7,8], and H2 [9]. Nevertheless, research has seldom been focused on the formaldehyde sensing properties of the material. In this investigation, the CdOmixed In2O3 was prepared with solidstate synthesis technology and characterized by Xray diffraction and SEM images. Gas sensors for indirectheating based on CdOIn2O3 sensing materials were fabricated. The formaldehyde sensing properties of the mixed oxides were determined. 2. Experimental All the chemical reagents used in the experiments were obtained from mercial sources as guaranteedgrade reagents and used without further purification. Based on our preliminary experiments, In2O3 or CdO does not have good sensing properties to formaldehyde. CdOIn2O3 powders were prepared from CdCO3 and In2O3. CdCO3–In2O3 samples with various phase positions were studied. The Cd:In = 1: weight ratio was found to be the most promising for the sensing properties to formaldehyde gas. CdCO3–In2O3 samples mixed with distilled deionized water were round carefully to about 50–500 nm size, and then the samples were calcined at 500, 650, 750, and 850 .C,respectively, for 1 h in air. Xray diffraction (XRD, Rigaku D/MAX3B powder diffractometer) with a copper target and K. radiation (λ = 176。 A) was used for the phase identification, where the diffracted Xray intensities were recorded as a function of 2θ. The sample was scanned from 10. to 70. (2θ) in steps of .. The mean crystallite sizes (Rx) were measured from XRD peaks at a scan rate of 2./min based on the Scherrer’s equation: Rx = (Bcos θ), where λis the wavelength of Xray, θ is the diffraction angle, and B is the true halfpeak width. Scanning electron microscopy (SEM) photographs were obtained by XL30ESEMTMP, — 43 — Holland. The sensors of indirect heating were fabricated according to the literature [13]. The mixed material used as a sensitive body was fabricated on an alumina tube with Au electrodes and platinum wires. A Ni–Cr alloy wire crossing the alumina tube was used as a resistor. This resistor ensured both substrate heating and temperature control. The elements were sintered at 650 .C for 1 h in air. Thickness of the s。