化學專業(yè)外文資料翻譯--具有高靈敏度的甲醛氣體傳感器的制備及其氣敏特性(存儲版)
【正文】 gap ( eV), whose electron concentration is determined mainly by the concentration of stoichiometric defects (such as oxygen vacancy) like other metal oxide semiconductors. In view of the sensing mechanism, the particle size, defects, the properties of surface and interface, and stoichiometry directly affect 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。當傳感器接觸甲醛氣體時，被捕獲的電子以吸附狀態(tài)被釋放，導致傳感器電阻減小。作為一個高靈敏度的傳感器，它可以測量非常低濃度，甚至百萬分之一。 如圖 4 所示，響應的抵押 – 氧化銦基于傳感器的氧化鉻和氧化銦在 95 度操作時的響應展示了對氣體濃度的良好依賴性。大多數(shù)粒子有不規(guī)則的形態(tài)，顆粒大小的范圍是 100– 500 納米。氧化銦和氧化鉻的外形展現(xiàn)了一個很高的結晶度。焙燒后，基于氧化銦的敏感物質(zhì)的厚度大約為 毫米。根據(jù) Scherrer 的公式： Rx = (B cos θ), 平均晶粒尺寸（接收）測量從 X 射線衍射峰以每分鐘 2176。氧化鎘：氧化銦 =1 : 重量比被認為是最有希望的甲醛氣體的傳感特性。然而，研究很少集中在甲醛傳感器的材料特性。 雖然半導體金屬氧化物氣體傳感器提供了對有毒氣體 或可燃性氣體的安全檢測，但是他們?nèi)匀挥幸欢ǖ木窒扌?，如靈敏度，選擇性，長期穩(wěn)定性等等。結果表明，在低操作溫度該傳感器對于甲 醛具有良好的反應性能，使他們成為甲醛氣體檢測最有希望的候選 材料 。操作溫度對傳感器響應的影響氧化鉻和氧化銦傳感器的氣體濃度特性的對比已經(jīng)研究過了。我們目前的調(diào)查主要涉及與甲醛的檢測。他們已經(jīng)很好的研究了檢測大部分重要氣體的傳感器材料，如乙醇，一氧化碳，二氧化氮，和氫氣。不同階段碳酸鹽 – 氧化銦樣品的成分已經(jīng)研究過了。為一個單位進行掃描。這些元素在
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