Transition Metal Embedded Two-Dimensional C3N4鈥揋raphene Nanocomposite: A Multifunctional Material

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• 作者：Dibyajyoti Ghosh ; Ganga Periyasamy ; Swapan K. Pati
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：July 17, 2014
• 年：2014
• 卷：118
• 期：28
• 页码：15487-15494
• 全文大小：425K
• ISSN：1932-7455

文摘

The lack of intrinsic spin polarization in graphene as well as in its several composites limits their usage as suitable spintronic material. Using long-range dispersion corrected density functional theory, we explore the structural, electronic, magnetic, and optical properties of recently synthesized [Liu, Q.; Zhang, J. Langmuir2013, 29, 3821鈭?828] two-dimensional graphitic carbon nitride (g-C₃N₄) stacked graphene (C₃N₄@graphene) where 3d transition metals (TMs) are embedded in the cavity of g-C₃N₄ (TM-C₃N₄@graphene). The incorporation of TMs modifies the structure of C₃N₄@graphene negligibly and keeps graphene almost as in its pristine form. TM inclusion makes the narrow-gap semiconducting C₃N₄@graphene as metallic. Charge-transfer analysis shows that the TM-C₃N₄ transfers electrons from the 3d-orbital of TM to the conduction band of graphene, making it n-doped in nature. Importantly, Cr, Fe, Co, and Ni embedded C₃N₄@graphene shows long-range ferromagnetic coupling among TMs in their ground state. The magnetic ordering appears due to suitable ferromagnetic d鈥損 exchange interaction, which is absent in paramagnetic V- and Mn-C₃N₄@graphene sheets. Furthermore, calculated high charge carrier densities of the n-doped graphene layer in these nanocomposites are quite promising for its usage in ultrafast electronics. Performing Heisenberg model based Monte Carlo simulations, we predict the Curie temperatures for Cr- and Fe-C₃N₄@graphene as 381 and 428 K, respectively. Moreover, these sheets also demonstrate prominent visible light response, which gives us a clue about their probable photocatalytic activity. Thus, the present study exhibits the true multifunctional behavior of TM-C₃N₄@graphene by demonstrating its usage in various fields, such as memory devices, spintronics, ultrafast electronics, photocatalysis, etc.