Wang Qian, Sun Qiang, Jena Puru, Kawazoe Yoshiyuki
Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
ACS Nano. 2009 Mar 24;3(3):621-6. doi: 10.1021/nn800815e.
The capability of AlN nanostructures (nanocages, nanocones, nanotubes, and nanowires) to store hydrogen has been studied using gradient-corrected density functional theory. In contrast to bulk AlN, which has the wurtzite structure and four-fold coordination, the Al sites in AlN nanostructures are unsaturated and have two- and three-fold coordination. Each Al atom is capable of binding one H(2) molecule in quasi-molecular form, leading to 4.7 wt % hydrogen, irrespective of the topology of the nanostructures. With the exception of AlN nanotubes, energetics does not support the adsorption of additional hydrogen. The binding energies of hydrogen to these unsaturated metal sites lie in the range of 0.1-0.2 eV/H(2) and are ideal for applications under ambient thermodynamic conditions. Furthermore, these materials do not suffer from the clustering problem that often plagues metal-coated carbon nanostructures.
利用梯度校正密度泛函理论研究了氮化铝纳米结构（纳米笼、纳米锥、纳米管和纳米线）储存氢的能力。与具有纤锌矿结构和四重配位的块状氮化铝不同，氮化铝纳米结构中的铝位点不饱和，具有二重和三重配位。每个铝原子能够以准分子形式结合一个H₂分子，产生4.7 wt%的氢，与纳米结构的拓扑结构无关。除了氮化铝纳米管外，能量学不支持额外氢的吸附。氢与这些不饱和金属位点的结合能在0.1 - 0.2 eV/H₂范围内，非常适合在环境热力学条件下应用。此外，这些材料不存在经常困扰金属包覆碳纳米结构的团聚问题。
