Fomekong Roussin Lontio, Kelm Klemens, Saruhan Bilge
Higher Teacher Training College, University of Yaounde I, Yaounde P.O. BOX 47, Cameroon.
German Aerospace Center (DLR), Institute of Materials Research, 51147 Cologne, Germany.
Sensors (Basel). 2020 Oct 22;20(21):5992. doi: 10.3390/s20215992.
This work deals with the substantially high-temperature hydrogen sensors required by combustion and processing technologies. It reports the synthesis of undoped and Ni-doped TiO (with 0, 0.5, 1 and 2 mol.% of Ni) nanoparticles by a co-precipitation method and the obtained characteristics applicable for this purpose. The effect of nickel doping on the morphological variation, as well as on the phase transition from anatase to rutile, of TiO was investigated by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The resistive sensors prepared with these powders were tested toward H at 600 °C. The results indicate that 0.5% Ni-doped TiO with almost equal amounts of anatase and rutile shows the best H sensor response (ΔR/R0 = 72%), response rate and selectivity. The significant improvement of the sensing performance of 0.5% Ni-doped TiO is mainly attributed to the formation of the highest number of n-n junctions present between anatase and rutile, which influence the quantity of adsorbed oxygen (i.e., the active reaction site) on the surface and the conductivity of the material.
这项工作涉及燃烧和加工技术所需的高温氢气传感器。它报道了通过共沉淀法合成未掺杂和镍掺杂的TiO（镍含量为0、0.5、1和2 mol.%）纳米颗粒以及为此目的所获得的特性。通过扫描电子显微镜、X射线衍射和拉曼光谱研究了镍掺杂对TiO形态变化以及从锐钛矿到金红石相变的影响。用这些粉末制备的电阻式传感器在600℃下对氢气进行了测试。结果表明，具有几乎等量锐钛矿和金红石的0.5%镍掺杂TiO表现出最佳的氢气传感器响应（ΔR/R0 = 72%）、响应速率和选择性。0.5%镍掺杂TiO传感性能的显著改善主要归因于锐钛矿和金红石之间形成了数量最多的n-n结，这影响了材料表面吸附氧的量（即活性反应位点）和材料的电导率。
