Xylene sensor using double-layered thin film and Ni-deposited porous alumina
Xylene sensor using double-layered thin film and Ni-deposited porous alumina
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DOI：
10.1016/j.snb.2013.01.024
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发表时间：
2013-05
影响因子：
8.4
通讯作者：
Tomo Akiyama;Yurie Ishikawa;K. Hara
中科院分区：
文献类型：
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作者：
Tomo Akiyama;Yurie Ishikawa;K. Hara
提出了一种在多孔氧化铝上沉积双层金属氧化物薄膜和镍催化剂的二甲苯传感器。传感膜具有双层结构，第一层为Fe 2 O3 + TiO 2（5mol%）+MgO（4mol%），第二层为WO 3 + TiO 2（10mol%）。第一层和第二层的厚度分别为200nm和70nm。通过采用双层结构，提高了响应和稳定性。将Ni沉积的多孔氧化铝放置在感测膜上。多孔氧化铝中的孔是圆柱形的。孔径约为200 nm，孔高约为60μm。二甲苯气体穿过多孔氧化铝中的Ni沉积孔到达传感膜。沉积的Ni的催化作用增强了二甲苯气体的化学活性及其在传感膜上的吸收量。因此，传感器对二甲苯气体高度敏感。该传感器能够检测浓度低至0.07ppm的二甲苯。此外，对二甲苯气体的选择性是令人满意的。在340°C的工作温度下，响应时间和恢复时间分别约为20 s和300 s。所有的薄膜和Ni都是通过射频溅射沉积的，而多孔氧化铝是通过铝的阳极氧化形成的。
A xylene sensor using a double-layered metal-oxide thin film and Ni-catalyst deposited on a porous alumina is presented. The sensing film has a double-layered structure; the first layer is Fe2O3+TiO2(5mol%)+MgO (4mol%), and the second layer is WO3+TiO2(10mol%). The thicknesses of the first and second layers are 200nm and 70nm, respectively. Both response and stability are improved by adopting a double-layered structure. The Ni-deposited porous alumina is placed over the sensing film. The pores in the porous alumina are cylindrical. The inner diameter and the height of the pores are about 200nm and 60μm, respectively. Xylene gas goes through the Ni-deposited pores in the porous alumina to reach the sensing film. The catalytic action of the deposited Ni enhances the chemical activity of xylene gas and the amount of its absorption on the sensing film. Thus the sensor is highly sensitive to xylene gas. The sensor is capable of detecting xylene at a concentration as low as 0.07ppm. Moreover, the selectivity to xylene gas is satisfactory. The response and recovery times are approximately 20s and 300s, respectively, at an operating temperature of 340°C. All films and Ni are deposited by rf sputtering while the porous alumina is formed by anodic oxidation of aluminum.