Graduate Institute of Electro-Optical Engineering and Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology , Taipei, 106 Taiwan, R.O.C.
ACS Appl Mater Interfaces. 2017 Apr 5;9(13):12064-12072. doi: 10.1021/acsami.7b00338. Epub 2017 Mar 27.
Herein, we report the novel nanostructural interfaces of self-assembled hierarchical ZnO nanotubes/graphene (ZNT/G) with three different growing times of ZNTs on graphene substrates (namely, SH, SH, and SH). Each sample was fabricated with interdigitated electrodes to form hydrogen sensors, and their hydrogen sensing properties were comprehensively studied. The systematic investigation revealed that SH sensor exhibits an ultrahigh sensor response even at a low detection level of 10 ppm (14.3%) to 100 ppm (28.1%) compared to those of the SH and SH sensors. The SH sensor was also found to be well-retained with repeatability, reliability, and long-term stability of 90 days under hydrogenation/dehydrogenation processes. This outstanding enhancement in sensing properties of SH is attributed to the formation of a strong metalized region in the ZNT/G interface due to the inner/outer surfaces of ZNTs, establishing a multiple depletion layer. Furthermore, the respective band models of each nanostructure were also purposed to describe their heterostructure, which illustrates the hydrogen sensing properties. Moreover, the long-term stability can be ascribed by the heterostructured combination of ZNTs and graphene via a spillover effect. The salient features of this self-assembled nanostructure are its reliability, simple synthesis method, and long-term stability, which makes it a promising candidate for new generation hydrogen sensors and hydrogen storage materials.
在此，我们报告了一种新型的自组装分层 ZnO 纳米管/石墨烯（ZNT/G）纳米结构界面，该界面具有在石墨烯衬底上生长不同时间的 ZNTs（分别为 SH、SH 和 SH）。每个样品都用叉指电极制成了氢气传感器，并对其氢气传感性能进行了综合研究。系统的研究表明，SH 传感器具有超高的传感器响应，即使在低检测水平（10 ppm（14.3%）至 100 ppm（28.1%））下，也比 SH 和 SH 传感器的响应高。研究还发现，SH 传感器在氢化/脱氢过程中具有良好的重复性、可靠性和 90 天的长期稳定性。SH 传感器的这种出色的传感性能增强归因于 ZNT/G 界面中形成了一个强大的金属化区域，这是由于 ZNTs 的内外表面，建立了一个多重耗尽层。此外，还提出了每个纳米结构的相应能带模型，以描述它们的异质结构，从而解释了其氢气传感性能。此外，通过溢出效应，ZNTs 和石墨烯的异质结构组合可以解释其长期稳定性。这种自组装纳米结构的突出特点是其可靠性、简单的合成方法和长期稳定性，使其成为新一代氢气传感器和氢气储存材料的有前途的候选材料。
