低压氢传感在航天、油气传输、电池及真空计量等领域有重要作用，但目前低压氢传感手段不足。碳纳米管被广泛应用在气体传感技术开发中，但本征碳纳米管不能直接应用在氢分子检测中。通过实验，我们首先展示了一种基于多壁碳纳米管（MWNT）场发射的低压氢传感特性，但传感机理不清晰，MWNTs中掺杂的催化金属被认为是氢传感的关键因素。本项目中：（1）使用化学气相沉积，在金属基底直接生长MWNTs，实验研究场发射氢传感机理和MWNT的结构特征；（2）以第一性的密度泛函为基础，通过研究氢吸附下金属掺杂MWNT的电子能带、功函数、吸附能等的改变及对场发射时电子输运特性的影响，研究场发射氢传感机理；（3）深入研究氢传感器性能，探索提高灵敏度、扩展工作范围、提高响应速度的技术途径；（4）调控表面预处理和生长工艺，探索可控生长掺杂MWNT的技术途径。研究也将为掺杂MWNT在场发射、氢储存、电池材料等领域的应用奠定基础。

Low pressure hydrogen sensing is an important issue in many fileds, including space science, oil & gas transportation, and energy cell. Currently, there is only a limited number of low pressure hydrogen sensing techniques, which can't meet the actual needs. Carbon nanotubes are widely used in the developments of gas detection devices, but the intrinsic nanotubes are not capable of detecting hydrogen due to weak binding with nanotubes. We demonstrated for the first time a low pressure hydrogen sensing concept from MWNT field emission. The sensing mechanism is not clear yet, and the metal doping in the nanotubes is considered the key factor. In this project: 1) After growing the MWNTs on the metallic substrate directly by CVD, the sensing mechanism will be investigated from field emission study and the structural analysis. 2) Based on the first principal density functional theory, the doping MWNT's key feature parameters, including the electronic band, work function, and adsorption energy, will be calculated and electronic transportation performance during field emission will be investigated. Thus, the sensing mechanism will be studied theoretically. 3) The approaches of improving the sensitivity, extending the sensing range, and shortening the responding time will be studied. 4) The methods of controllable growth of doping MWNTs will be investigated by substrate treatments and CVD process controls.