Abstract Three-dimensional macroporous graphene sponges with different densities were investigated by angular dependent carbon K-edge X-ray Absorption Near Edge Spectroscopy (XANES) with a linearly polarized beam. The C K-edge XANES analysis shows an unexpected anisotropic behavior of the macroporous graphene random networks. The macroporous graphene sponges expectedly show an exceedingly lower dichroic ratio compared with that of the highly oriented pyrolytic graphite, but spectra clearly points out the occurrence of oriented hexagonal carbon planes. The anisotropy of the investigated samples exhibits a linear dependence with the measured density. The XANES analysis supports the presence of graphene-like, two-dimensional planar structures inside these synthetic sponges and correlate it with different structural networks and/or density in graphene sponges.

中文翻译：

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三维大孔石墨烯的结构各向异性：极化 XANES 研究

摘要 通过具有线性偏振光束的角度相关碳 K 边 X 射线吸收近边光谱 (XANES) 研究了具有不同密度的三维大孔石墨烯海绵。C K-edge XANES 分析显示了大孔石墨烯随机网络的意外各向异性行为。与高度取向的热解石墨相比，大孔石墨烯海绵预计显示出极低的二向色比，但光谱清楚地指出了取向六方碳平面的出现。研究样品的各向异性表现出与测量密度的线性相关性。XANES 分析支持类似石墨烯的存在，