Bai Byong Chol, Lee Young-Seak, Im Ji Sun
Chungnam National University, Institute of Chemical and Biological Engineering, Daejeon, 34134, Republic of Korea.
Chungnam National University, Departments of Applied Chemistry and Biological Engineering, Daejeon, 34134, Republic of Korea.
Sci Rep. 2019 Oct 8;9(1):14458. doi: 10.1038/s41598-019-50707-x.
In this study, we evaluated the potential use of CuO-ZnO combination structures with activated carbon fibers (ACFs) for the adsorption (by ACFs) and electrochemical detection (by CuO-ZnO) by of SO gas. The gas adsorptivity was concluded to improve as a result of the synergetic effects of physical adsorption by the micropores and mesopores, the specific surface area developed by chemical activation and the chemical adsorption reaction between SO and the transition metals introduced in the CuO-ZnO combination structures. From comparison of the SO sensing properties, the CuO-ZnO combination structures with ACFs exhibited the fastest sensing capability. This result can be attributed to the larger specific surface area of the semiconductor, which extended its depletion layer by forming p-type CuO/n-type ZnO junctions. This phenomenon led to good SO detection through a decrease in the resistance; thus, the contributions of the sensing responses of p-type CuO and n-type ZnO represent a predominant characteristic of the sensor. These types of mechanisms were proven through various physicochemical and electrical characterization methods, especially through evaluation of the SO sensing capability of the CuO-ZnO combination structures with ACFs. The reversible sensing capability indicates that the p-n junction structure changed the electrical properties of the ACFs, leading to an intriguing sensing mechanism.
在本研究中，我们评估了具有活性炭纤维（ACF）的CuO-ZnO组合结构用于吸附（通过ACF）和电化学检测（通过CuO-ZnO）SO气体的潜在用途。由于微孔和中孔的物理吸附、化学活化产生的比表面积以及SO与CuO-ZnO组合结构中引入的过渡金属之间的化学吸附反应的协同效应，气体吸附性得到了改善。通过比较SO传感特性，具有ACF的CuO-ZnO组合结构表现出最快的传感能力。这一结果可归因于半导体较大的比表面积，其通过形成p型CuO/n型ZnO结扩展了耗尽层。这种现象通过电阻降低实现了良好的SO检测；因此，p型CuO和n型ZnO的传感响应贡献代表了该传感器的主要特性。通过各种物理化学和电学表征方法，特别是通过评估具有ACF的CuO-ZnO组合结构的SO传感能力，证明了这些类型的机制。可逆传感能力表明p-n结结构改变了ACF的电学性质，导致了一种有趣的传感机制。
