Electronic and magnetic properties of acid-adsorbed nanoporous activated carbon fibers
Electronic and magnetic properties of acid-adsorbed nanoporous activated carbon fibers
复制标题
DOI：
10.1016/j.carbon.2007.10.037
复制
发表时间：
2008
期刊：
影响因子：
10.9
通讯作者：
S. Hao;K. Takai;F. Kang;T. Enoki
中科院分区：
文献类型：
--
作者：
S. Hao;K. Takai;F. Kang;T. Enoki
纳米多孔活性碳纤维（ACF）的特征在于纳米石墨域的3D无序网络，其由每个3-4个纳米石墨烯片的堆叠组成。在纳米石墨烯片的外围，产生非键边缘态的局部自旋。研究了ACF中边态自旋与吸附在纳米孔中的酸分子相互作用的磁性。HCl分子在纳米孔中物理吸附地凝聚，机械地压缩纳米石墨域，导致以磁切换效应的形式的边态自旋的磁矩的减少。硝酸分子，具有显着的氧化能力，受到从纳米石墨域的电荷转移。这引起边缘态自旋浓度的两步降低，其中第一步和第二步分别与直接面对纳米孔的纳米石墨烯片的电荷转移和与纳米石墨域内部的纳米石墨烯片的电荷转移有关。在稀释的HNO 3中，水分子的阻挡阻止了HNO 3分子与内部纳米石墨烯片的相互作用，使得电荷仅与直接面对纳米孔的石墨烯片转移;这导致自旋浓度的单步变化。
Nanoporous activated carbon fibers (ACFs) feature 3D disordered networks of nanographite domains that consist of stacks of 3–4 nanographene sheets each. At the peripheries of the nanographene sheets, the localized spins of a nonbonding edge state are created. The magnetic properties of the edge-state spins in ACFs are investigated in relation to the interaction with acid molecules adsorbed in the nanopores. HCl molecules condensed physisorptively in the nanopores mechanically compress the nanographite domains, resulting in the reduction of the magnetic moments of the edge-state spin in the form of a magnetic switching effect. HNO3molecules, which have significant oxidation ability, are subjected to charge transfer from the nanographite domains. This induces a two-step reduction in the edge-state spin concentration, wherein the first and second steps are related to the charge transfer with the nanographene sheets that directly face the nanopores and that with the nanographene sheets in the interior of the nanographite domains, respectively. In diluted HNO3, the blockade by water molecules prevents the interaction of the HNO3molecules with the interior nanographene sheets, allowing for charge transfer only with the graphene sheets that directly face the nanopores; this results in a single-step change in the spin concentration.