Sisman Orhan, Zappa Dario, Maraloiu Valentin-Adrian, Comini Elisabetta
Department of Functional Materials, FunGlass Center, Alexander Dubcek University of Trencin, 91150 Trencin, Slovakia.
Sensor Laboratory, Department of Information Engineering (DII), University of Brescia, Via Valotti 7, 25123 Bresica, Italy.
Materials (Basel). 2023 Jul 3;16(13):4802. doi: 10.3390/ma16134802.
Unlike the conventional one-dimensional (1D) core-shell nanowires (NWs) composed of -type shells and -type cores, in this work, an inverse design is proposed by depositing -type ZnO (shell) layers on the surface of -type CuO (core) NWs, to have a comprehensive understanding of their conductometric gas-sensing kinetics. The surface morphologies of bare and core-shell NWs were investigated by field emission scanning electron microscope (FE-SEM). The ZnO shell layer was presented by overlay images taken by electron dispersive X-ray spectroscopy (EDX) and high-resolution transmission electron microscopy (HRTEM). The pronounced crystalline plane peaks of ZnO were recorded in the compared glancing incident X-ray diffraction (GI-XRD) spectra of CuO and CuO-ZnO core-shell NWs. The ZnO shell layers broaden the absorption curve of CuO NWs in the UV-vis absorption spectra. As a result of the heterostructure formation, the intrinsic -type sensing behavior of CuO NWs towards 250 and 500 ppm of hydrogen () switched to -type due to the deposition of ZnO shell layers, at 400 °C in dry airflow.
与由n型壳层和p型核组成的传统一维（1D）核壳纳米线（NWs）不同，在本工作中，通过在p型CuO（核）NWs表面沉积n型ZnO（壳）层提出了一种反向设计，以全面了解其电导气敏动力学。通过场发射扫描电子显微镜（FE-SEM）研究了裸NWs和核壳NWs的表面形貌。通过电子色散X射线光谱（EDX）和高分辨率透射电子显微镜（HRTEM）拍摄的叠加图像展示了ZnO壳层。在CuO和CuO-ZnO核壳NWs的比较掠入射X射线衍射（GI-XRD）光谱中记录了ZnO明显的晶面峰。ZnO壳层拓宽了CuO NWs在紫外-可见吸收光谱中的吸收曲线。由于异质结构的形成，在干燥气流中400℃时，由于ZnO壳层的沉积，CuO NWs对250和500 ppm氢气（H₂）的本征p型传感行为转变为n型。
