Immobilization of Reduced Graphene Oxide on Hydrogen-Terminated Silicon Substrate as a Transparent Conductive Protector.
Immobilization of Reduced Graphene Oxide on Hydrogen-Terminated Silicon Substrate as a Transparent Conductive Protector.
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DOI：
10.1021/acs.langmuir.7b01688
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
Y. Tu;T. Utsunomiya;Sho Kokufu;Masahiro Soga;T. Ichii;H. Sugimura
中科院分区：
文献类型：
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作者：
Y. Tu;T. Utsunomiya;Sho Kokufu;Masahiro Soga;T. Ichii;H. Sugimura
硅是一种很有前途的光电化学和光催化反应的电极材料。然而，硅的化学活性表面在暴露于氧化环境时将容易被氧化。我们将氧化石墨烯（GO）固定在氢封端的硅（H-Si）上，并通过紫外（UV）和真空紫外（VUV）照射将其还原。这充当了一个导电层，以保护H-Si免受氧化。通过X射线光电子能谱研究了GO的元素演化，发现GO在沉积到H-Si上后不久就被部分还原，在UV或VUV光照射后进一步还原。真空紫外光还原证明了ca。与基于照射剂量的UV减少相比，效率高100倍。还原的氧化石墨烯（rGO）的饱和氧碳比（RO/C）为0.21 ± 0.01，这低于GO在SiO2衬底上的光还原。这表明H-Si在GO光还原反应中起着重要的辅助作用。在水中超声处理rGO覆盖的H-Si样品后，没有观察到明显的rGO剥离，这表明rGO被固定在H-Si上。导电原子力显微镜观察到，rGO覆盖区域的H-Si表面保持导电性，而暴露的H-Si区域变得绝缘。经验证，rGO能够保护活性H-Si免受周围环境下的氧化。
Silicon is a promising electrode material for photoelectrochemical and photocatalytic reactions. However, the chemically active surface of silicon will be easily oxidized when exposed to the oxidation environment. We immobilized graphene oxide (GO) onto hydrogen-terminated silicon (H-Si) and reduced it through ultraviolet (UV) and vacuum-ultraviolet (VUV) irradiation. This acted as an ultrathin conductive layer to protect H-Si from oxidation. The elemental evolution of GO was studied by X-ray photoelectron spectroscopy, and it was found that GO was partially reduced soon after the deposition onto H-Si and further reduced after UV or VUV light irradiation. The VUV photoreduction demonstrated ca. 100 times higher efficiency compared to the UV reduction based on the irradiation dose. The saturated oxygen-to-carbon ratio (RO/C) of the reduced graphene oxide (rGO) was 0.21 ± 0.01, which is lower than the photoreduction of GO on SiO2 substrate. This indicated the H-Si played an important role in assisting the photoreduction of GO. No obvious exfoliation of rGO was observed after sonicating the rGO-covered H-Si sample in water, which indicated rGO was immobilized on H-Si. The electrical conductivity of H-Si surface was maintained in the rGO-covered region while the exposed H-Si region became insulating, which was observed by conductive atomic force microscopy. The rGO was verified capable to protect the active H-Si against the oxidation under an ambient environment.