کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7148110 1462102 2013 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
La2O3-sensitized SnO2 nanocrystalline porous film gas sensors and sensing mechanism toward formaldehyde
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
La2O3-sensitized SnO2 nanocrystalline porous film gas sensors and sensing mechanism toward formaldehyde
چکیده انگلیسی
In this work, a smart platform was reported with an ability to rapidly screen the gas sensing properties of metal oxide gas sensors which were loaded on a single material chip with a capability of 36 sensor films. Among the SnO2-based material sensitized with various catalysts (Mo, Pd, Cd, Mn, Pt, Y, La, Ce, Pr, Sm, Gd) in different concentrations, a significant enhancement of sensing performance was observed for the film with surface functionalized La. To intrinsically investigate its sensitization mechanism, the changes in microstructure and surface valence of the SnO2-based materials were characterized by XRD, SEM, XPS, PL, HRTEM and EDX. It is demonstrated that the hydrated lanthanum chloride transformed to La2O3 with an intermediate of LaOCl during the sintering process of the samples. Thus, the sensitization mechanism of La2O3 can be concluded into two items: (1) numerous of oxygen vacancies are newly created on the SnO2 surface through the LaOCl to La2O3 transformation resulted in the enhancement of gas-sensing properties; (2) the chemisorbed peroxide O22− on La2O3 surface has the ability to cause an H-abstraction reaction with hydrocarbon, which may account for the decrease of optimum temperature toward formaldehyde.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sensors and Actuators B: Chemical - Volume 188, November 2013, Pages 137-146
نویسندگان
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