Eom Nu Si A, Cho Hong-Baek, Lim Hyo-Ryoung, Hwang Tea-Yeon, Song Yoseb, Choa Yong-Ho
Electrochemistry Department, Korea Institute of Materials Science Changwon 51508 Republic of Korea.
Department of Fusion Chemical Engineering, Hanyang University Ansan 15588 Republic of Korea
RSC Adv. 2018 Aug 24;8(52):29995-30001. doi: 10.1039/c8ra05520c. eCollection 2018 Aug 20.
In this study, the sensing properties of palladium-doped porous silicon (Pd/p-Si) substrates for low-ppm level detection of toxic HS gas are investigated. A Si substrate with dead-end pores ranging from nano- to macroscale was generated by a combined process of metal-assisted chemical etching (MacE) and electrochemical etching with tuned reaction time, in which nano-Pd catalysts were decorated by E-beam sputtering deposition. The sensing properties of the Pd/p-Si were enhanced as the thickness of the substrate layer increased; along with the resulting variation in surface area, this resulted in superior HS sensing performances in the low-ppm range (less than 3 ppm), with a detection limit of 300 ppb (sensitivity 30%) at room temperature. Furthermore, the sensor displayed excellent selectivity toward the hazardous HS molecules in comparison with various other reducing gases, including NO, CO, NH, and H, showing its potential for application in workplaces or environments affected by other toxic gases. The enhancement in sensing performance was possibly due to the increased dispersion and surface area of Pd nano-catalysts, which led to an increase in chemisorption sites of adsorbate molecules.
在本研究中，对钯掺杂多孔硅（Pd/p-Si）衬底用于低ppm水平有毒HS气体检测的传感特性进行了研究。通过金属辅助化学蚀刻（MacE）和电化学蚀刻相结合的工艺，在经过调整的反应时间下生成了具有从纳米级到宏观尺度的盲孔的硅衬底，其中通过电子束溅射沉积对纳米钯催化剂进行了修饰。随着衬底层厚度的增加，Pd/p-Si的传感特性得到增强；随着表面积的相应变化，这导致在低ppm范围（小于3 ppm）内具有卓越的HS传感性能，在室温下检测限为300 ppb（灵敏度30%）。此外，与包括NO、CO、NH和H在内的各种其他还原气体相比，该传感器对有害HS分子表现出优异的选择性，显示出其在受其他有毒气体影响的工作场所或环境中的应用潜力。传感性能的增强可能归因于钯纳米催化剂分散度和表面积的增加，这导致吸附质分子的化学吸附位点增加。
