钯基复合薄膜的氢气传感器研究
发布时间：2018-12-06 13:43
【摘要】：氢气探测技术在众多应用领域中都是必不可少的,例如氨和醇的制备过程、航天飞机起飞降落时的氢气泄露探测以及氢能源电池氢的实时监测,因此研发高性能的氢气传感器是一种必然。钯(Pd)由于其能够吸收大量氢气的优秀性能、对氢气的高度选择性而广泛运用在氢气传感器的研发。同时,Pd基氢气传感器也因为其简单的器件结构和制备过程而备受研究者们关注,使得其得到了快速的发展。本文将采用基于钯薄膜的复合薄膜材料作为氢气传感器的敏感层材料,制备出性能优良的氢气传感器,对氢气传感器的性能作相关测试,并且分析复合薄膜材料的氢气敏感原理和对氢气传感器性能改善的原因。本文的研究内容主要包括如下几个部分:首先,本论文采用膨胀动力学理论研究了氢气传感器的响应时间与钯纳米颗粒体积大小的相关关系,然后制备了多孔钯纳米薄膜氢气传感器,并且测试了性能指标,包括动态响应、响应时间、恢复时间、响应度、重复性,测试发现多孔钯纳米薄膜氢气传感器相较与致密钯膜氢气传感器而言,具有更加快速的响应和更加稳定的性能。随后,文章研究了磷酸扩孔工艺浓度和时间对氢气传感器性能的影响,研究发现扩孔时间和扩孔浓度对氢气传感器性能都带来显著的影响,并且通过大量的实验寻找到了最佳的工艺条件是扩孔浓度为5%、扩孔时间是30分钟,所制备得到的氢气传感器的响应时间在氢气浓度为1%时达到了19s,同时,通过测试复合薄膜的SEM图像分析了扩孔工艺对氢气传感器所带来的影响的原因,提出了“裂结”效应和吸氢效应对氢气传感器的双重影响。为了进一步优化氢气传感器的性能,本论文将二氧化钛层加入多孔钯纳米薄膜氢气传感器,形成多孔钯-二氧化钛纳米薄膜氢气传感器。然后测试了二氧化钛层厚度对氢气传感器性能带来的影响,确定了二氧化钛喷涂含量为1ml时,二氧化钛层厚度约为10nm时氢气传感器的性能最佳,在氢气浓度为8000ppm时,响应时间为5s,恢复时间达到了9s,同时也分析了二氧化钛层对氢气传感器性能影响的原因极其相关机理。最后,作为对多孔层的一种模拟,本文创新性地提出了一种全新的交错碳纳米管结构,并采用二次喷涂法制备了交错碳纳米管薄膜,然后将钯薄膜直接溅射于碳纳米管薄膜上,得到钯-碳纳米管复合薄膜氢气传感器,测试了其对氢气响应有着质的提升。作为对照,文章还制备了全覆盖碳纳米管薄膜和钯的复合薄膜氢气传感器,研究发现钯-交错碳纳米管复合薄膜氢气传感器的性能更佳,在氢气浓度为2%时响应时间达到了8s,同时具有更强的稳定性并且选择性良好。
[Abstract]:Hydrogen detection is essential in many applications, such as the preparation of ammonia and alcohol, hydrogen leak detection during the shuttle's take-off and landing, and the real-time monitoring of hydrogen for hydrogen energy batteries. Therefore, it is inevitable to develop high performance hydrogen sensors. Palladium (Pd) has been widely used in the development of hydrogen sensors because of its excellent performance in absorbing large amounts of hydrogen and its high selectivity to hydrogen. At the same time, Pd based hydrogen sensors have attracted much attention because of their simple device structure and fabrication process. In this paper, the composite thin film based on palladium thin film is used as the sensitive layer material of hydrogen sensor, and the hydrogen sensor with excellent performance is prepared, and the performance of hydrogen sensor is tested. The principle of hydrogen sensitivity and the reason of improving the performance of hydrogen sensor are analyzed. The main contents of this thesis are as follows: firstly, the relationship between the response time of hydrogen sensor and the volume of palladium nanoparticles is studied by using the expansion dynamics theory. Then the porous palladium nanofilm hydrogen sensor was prepared, and the performance parameters were tested, including dynamic response, response time, recovery time, responsivity, repeatability, etc. It is found that the porous PD nanofilm hydrogen sensor has faster response and more stable performance than the dense PD film hydrogen sensor. Then, the effect of the concentration and time of phosphoric acid reaming on the performance of hydrogen sensor is studied. It is found that the time of reaming and the concentration of reaming have a significant effect on the performance of hydrogen sensor. And through a lot of experiments, we find the best process condition is that the reaming concentration is 5, the reaming time is 30 minutes, the response time of the prepared hydrogen sensor is 19 s when the hydrogen concentration is 1, at the same time, By testing the SEM images of the composite film, the reasons for the influence of the reaming process on the hydrogen sensor are analyzed, and the double effects of the "crack junction" effect and the hydrogen absorption effect on the hydrogen sensor are proposed. In order to further optimize the performance of hydrogen sensor, the porous palladium thin film hydrogen sensor was formed by adding titanium dioxide layer into porous palladium thin film hydrogen sensor. Then the effect of titanium dioxide thickness on the performance of hydrogen sensor is tested. When the content of TIO _ 2 spraying is 1ml, the performance of hydrogen sensor is best when the thickness of TIO _ 2 is about 10nm, and the hydrogen concentration is 8000ppm. The response time is 5 s and the recovery time is 9 s. At the same time, the influence of titanium dioxide layer on the performance of hydrogen sensor is analyzed. Finally, as a simulation of the porous layer, a novel interlaced carbon nanotube structure was proposed, and the interlaced carbon nanotube film was prepared by secondary spraying method, and then the palladium film was deposited directly on the carbon nanotube film. Palladium-carbon nanotube composite film hydrogen sensor was obtained and its response to hydrogen was tested. As a control, the composite thin film hydrogen sensor with fully covered carbon nanotube film and palladium was prepared, and the performance of the palladium interleaved carbon nanotube composite film hydrogen sensor was found to be better than that of the palladium interleaved carbon nanotube composite film hydrogen sensor. When the hydrogen concentration is 2, the response time is 8 s, and the stability is stronger and the selectivity is good.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212
本文编号：2366116
[Abstract]:Hydrogen detection is essential in many applications, such as the preparation of ammonia and alcohol, hydrogen leak detection during the shuttle's take-off and landing, and the real-time monitoring of hydrogen for hydrogen energy batteries. Therefore, it is inevitable to develop high performance hydrogen sensors. Palladium (Pd) has been widely used in the development of hydrogen sensors because of its excellent performance in absorbing large amounts of hydrogen and its high selectivity to hydrogen. At the same time, Pd based hydrogen sensors have attracted much attention because of their simple device structure and fabrication process. In this paper, the composite thin film based on palladium thin film is used as the sensitive layer material of hydrogen sensor, and the hydrogen sensor with excellent performance is prepared, and the performance of hydrogen sensor is tested. The principle of hydrogen sensitivity and the reason of improving the performance of hydrogen sensor are analyzed. The main contents of this thesis are as follows: firstly, the relationship between the response time of hydrogen sensor and the volume of palladium nanoparticles is studied by using the expansion dynamics theory. Then the porous palladium nanofilm hydrogen sensor was prepared, and the performance parameters were tested, including dynamic response, response time, recovery time, responsivity, repeatability, etc. It is found that the porous PD nanofilm hydrogen sensor has faster response and more stable performance than the dense PD film hydrogen sensor. Then, the effect of the concentration and time of phosphoric acid reaming on the performance of hydrogen sensor is studied. It is found that the time of reaming and the concentration of reaming have a significant effect on the performance of hydrogen sensor. And through a lot of experiments, we find the best process condition is that the reaming concentration is 5, the reaming time is 30 minutes, the response time of the prepared hydrogen sensor is 19 s when the hydrogen concentration is 1, at the same time, By testing the SEM images of the composite film, the reasons for the influence of the reaming process on the hydrogen sensor are analyzed, and the double effects of the "crack junction" effect and the hydrogen absorption effect on the hydrogen sensor are proposed. In order to further optimize the performance of hydrogen sensor, the porous palladium thin film hydrogen sensor was formed by adding titanium dioxide layer into porous palladium thin film hydrogen sensor. Then the effect of titanium dioxide thickness on the performance of hydrogen sensor is tested. When the content of TIO _ 2 spraying is 1ml, the performance of hydrogen sensor is best when the thickness of TIO _ 2 is about 10nm, and the hydrogen concentration is 8000ppm. The response time is 5 s and the recovery time is 9 s. At the same time, the influence of titanium dioxide layer on the performance of hydrogen sensor is analyzed. Finally, as a simulation of the porous layer, a novel interlaced carbon nanotube structure was proposed, and the interlaced carbon nanotube film was prepared by secondary spraying method, and then the palladium film was deposited directly on the carbon nanotube film. Palladium-carbon nanotube composite film hydrogen sensor was obtained and its response to hydrogen was tested. As a control, the composite thin film hydrogen sensor with fully covered carbon nanotube film and palladium was prepared, and the performance of the palladium interleaved carbon nanotube composite film hydrogen sensor was found to be better than that of the palladium interleaved carbon nanotube composite film hydrogen sensor. When the hydrogen concentration is 2, the response time is 8 s, and the stability is stronger and the selectivity is good.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212
【参考文献】
相关重要报纸文章 前1条
1 宋莉;周瑞华;周敢普;;上海氢燃料电池投入使用[N];科技日报;2005年
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