Synthesis and characterization of potassium-doped multilayer graphene prepared by wet process using potassium hydroxide
Synthesis and characterization of potassium-doped multilayer graphene prepared by wet process using potassium hydroxide
复制标题
氢氧化钾湿法制备钾掺杂多层石墨烯的合成与表征
DOI：
10.1088/2632-959x/ac1454
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发表时间：
2021
期刊：
影响因子：
3
通讯作者：
Yamada Takatoshi
中科院分区：
文献类型：
--
作者：
Masuzawa Tomoaki;Okigawa Yuki;Ogawa Shuichi;Takakuwa Yuji;Hatakeyama Kazuto;Yamada Takatoshi
采用氢氧化钾(KOH)水溶液湿化学法(KOH处理)研究了多层石墨烯的K掺杂。由飞行时间二次离子质谱仪(TOF-SIMS)获得的41个K+离子的深度分布证实了K原子沿堆积方向的存在。TOF-SIMS获得的41个K+离子的强度图像表明，K原子存在于整个区域。对于KOH处理的多层石墨烯，X射线衍射谱没有观察到K嵌入石墨烯层间的峰，在拉曼光谱中没有观察到G带峰的分裂和2D带峰的消失。X射线衍射仪和拉曼光谱均未确定石墨层间化合物的结构。然而，拉曼光谱中G带峰位置的上移表明，K原子被掺杂到石墨烯中。X-射线光电子能谱、碳1s谱表明，KOH处理导致了石墨烯边缘和/或结构域处的K-封端。此外，与原始石墨烯的C1S峰相比，在1 eV处出现了C1S肩峰。电导率随温度变化的测量结果表明，经KOH处理后，多层石墨烯的电导率有所提高。此外，电导率随着温度的升高而增大，这可以用能带重叠来解释。
Potassium (K) doping of multilayer graphene was demonstrated by means of a wet chemical process using potassium hydroxide (KOH) aqueous solution (KOH treatment). The presence of K atoms along the stacking direction was confirmed from depth profiles of 41 K+ ions obtained by time-of-flight secondary ion mass spectroscopy (TOF-SIMS). The intensity images of 41 K+ ions obtained by TOF-SIMS suggested that the K atoms existed throughout the whole area. For the KOH-treated multilayer graphene, no peak due to K intercalation between graphene layers was obtained by x-ray diffraction (XRD); in Raman spectra, splitting of the G-band peak and disappearance of the 2D-band peak were not observed. A graphite intercalation compound structure was not determined by either XRD or Raman results. However, the up-shift in the G-band peak position in the Raman spectra suggested that K atoms were doped in the graphene. X-ray photoelectron spectroscopy carbon 1s spectra implied that KOH treatment resulted in K-termination at the edges and/or domains of graphene. In addition, a C1s shoulder peak appeared at 1 eV higher binding energy compared to the C1s peak of pristine graphene. Temperature-dependent conductivity measurement results indicated that the conductivity of multilayer graphene was increased by KOH treatment. In addition, the conductivity increased with increasing temperature, which could be explained by band overlap.