Luo Na, Chen Yang, Zhang Dan, Guo Mengmeng, Xue Zhenggang, Wang Xiaohong, Cheng Zhixuan, Xu Jiaqiang
NEST lab, Department of Physics, Department of Chemistry, College of Sciences, Shanghai University, Shanghai 200444, PR China.
ACS Appl Mater Interfaces. 2020 Dec 16;12(50):56203-56215. doi: 10.1021/acsami.0c18369. Epub 2020 Dec 3.
Here we report the fabrication of a high performance metal oxide semiconductor (MOS) sensor for the detection of hydrogen sulfide (HS) using PdRh bimetal hollow nanocube (HC) with Rh-rich hollow frame and Pd-rich core frame as sensitizing materials. PdRh bimetal HC with the edge-length about 10 nm was prepared by chemical etching PdRh bimetal solid nanocube (SC) in HNO aqueous solution. The results of gas-sensing tests indicate that the response value order of the MEMS gas sensors based on MOSs (including ZnO, MoO and SnO) is as follows: > > . First, in the system of ZnO, gas sensor modified by PdRh (PdRh SC/ZnO and PdRh HC/ZnO) possess enhanced HS sensing performance with a better response and excellent low-concentration detection capability (down to 15 ppb) comparing to pure ZnO. The improved HS sensing performance could be attributed to the good conductivity of Rh-rich frame, the high catalytic activity of PdRh bimetal and formation of Schottky barrier-type junctions and defect. Second, PdRh HC/ZnO sensor shows better response (185-1 ppm of HS) compared to PdRh SC/ZnO sensor (108-1 ppm of HS), which is due to the higher specific surface area of PdRh HC/ZnO and good gas diffusion of the hollow structure. This work indicate that the sensitization characteristics of PdRh bimetal HC will provide new paradigms for the future development of the high performance sensor.
在此，我们报道了一种高性能金属氧化物半导体（MOS）传感器的制备，该传感器用于检测硫化氢（HS），使用富Rh空心框架和富Pd核心框架的PdRh双金属空心纳米立方体（HC）作为敏感材料。通过在硝酸水溶液中化学蚀刻PdRh双金属实心纳米立方体（SC）制备边长约为10 nm的PdRh双金属HC。气敏测试结果表明，基于MOSs（包括ZnO、MoO和SnO）的MEMS气体传感器的响应值顺序如下：> > 。首先，在ZnO体系中，与纯ZnO相比，由PdRh修饰的气体传感器（PdRh SC/ZnO和PdRh HC/ZnO）具有增强的HS传感性能，具有更好的响应和出色的低浓度检测能力（低至15 ppb）。HS传感性能的提高可归因于富Rh框架的良好导电性、PdRh双金属的高催化活性以及肖特基势垒型结和缺陷的形成。其次，PdRh HC/ZnO传感器比PdRh SC/ZnO传感器（108 - 1 ppm的HS）表现出更好的响应（185 - 1 ppm的HS），这是由于PdRh HC/ZnO具有更高的比表面积和空心结构良好的气体扩散性。这项工作表明，PdRh双金属HC的敏化特性将为高性能传感器的未来发展提供新的范例。
