Zhai Zhaofeng, Huang Nan, Yang Bing, Liu Lusheng, Li Haining, Chen Junnan, Zhang Bingsen, Jiang Xin
Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , No. 72 Wenhua Road , Shenyang 110016 , China.
School of Materials Science and Engineering , University of Science and Technology of China , No. 72 Wenhua Road , Shenyang 110016 , China.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8522-8532. doi: 10.1021/acsami.9b18004. Epub 2020 Feb 10.
The integration of sp-/sp-bonded carbon has aroused increasing attention on attaining a great electron field emission (EFE) performance. Herein, a novel hierarchical diamond@carbon nanowalls/diamond (D@C/D) architecture is facilely prepared through the growth of the hybrid carbon nanowalls/diamond (C/D) film followed by the in situ hydrogen plasma treatment using microwave plasma chemical vapor deposition. The hierarchical D@C/D architecture is composed of thin diamond nanoplatelets sandwiched into carbon nanowalls (CNWs) as the bottom layer and the thickened nanoplatelets constituted by diamond nanograins as the upper layer. The hydrogen plasma plays an effective role in the transformation of sacrificial sp-bonded CNWs to sp-bonded diamond, eventually leading to the template thickening of diamond nanoplatelets in the upper layer. Impressively, the D@C/D-90 film demonstrates much better EFE behaviors of low turn-on potential ( = 4.3 V μm), high current density (@8 V μm = 20.81 mA cm), and superior long-term stability, in comparison with the pristine C/D film ( = 6 V μm, @8 V μm = 0.33 mA cm). The enhanced EFE performance of the hierarchical D@C/D film is ascribed to the well-established graphite pathway for electrons transported from the bottom to the top and the increased diamond emitting sites with negative electron-affinity and robust nature at the top. This work will promote the development of the high-performance cathode EFE material based on hybrid sp/sp-bonded carbon, and the method proposed here also provides an effective strategy to construct a diamond nanostructure for various applications.
sp/sp 键合碳的集成在实现优异的电子场发射（EFE）性能方面引起了越来越多的关注。在此，通过生长混合碳纳米壁/金刚石（C/D）薄膜，然后使用微波等离子体化学气相沉积进行原位氢等离子体处理，简便地制备了一种新型的分级金刚石@碳纳米壁/金刚石（D@C/D）结构。分级 D@C/D 结构由夹在碳纳米壁（CNWs）中的薄金刚石纳米片作为底层和由金刚石纳米颗粒构成的加厚纳米片作为上层组成。氢等离子体在将牺牲性的 sp 键合 CNWs 转变为 sp 键合金刚石方面发挥了有效作用，最终导致上层金刚石纳米片的模板增厚。令人印象深刻的是，与原始 C/D 薄膜（ = 6 V μm，@8 V μm = 0.33 mA cm）相比，D@C/D - 90 薄膜表现出更好的 EFE 行为，具有低开启电位（ = 4.3 V μm）、高电流密度（@8 V μm = 20.81 mA cm）和优异的长期稳定性。分级 D@C/D 薄膜增强的 EFE 性能归因于从底部到顶部建立良好的电子传输石墨通道以及顶部具有负电子亲和力和坚固性质的增加的金刚石发射位点。这项工作将促进基于混合 sp/sp 键合碳的高性能阴极 EFE 材料的发展，并且这里提出的方法还为构建用于各种应用的金刚石纳米结构提供了一种有效策略。
