层状ZnO纳米材料的储氢性能研究

Study of Hydrogen Storage Properties of Layered ZnO Nanomaterial

为了得到层状ZnO纳米材料更为丰富和精确的储氢数据.文中采用密度泛函理论计算和巨正则蒙特卡罗方法模拟分别研究了ZnO单层不同吸附位与氢气分子的结合能力,层状ZnO纳米材料在常温(293K)及低温(77K)下储氢量与层间距和压强的关系.研究结果表明:在ZnO纳米单层六元环结构的中心位置结合能为0.259eV,层状ZnO纳米材料层间距为25,压强为20 MPa时,常温下对应的储氢质量分数为1.10%,低温下对应的储氢质量分数为4.12%.层状ZnO纳米材料能够实现储氢功能,在低温下储氢能力表现更为优异,随着层间距和压强增加其储氢量变大.

The study is aimed to collect more abundant and accurate hydrogen storage data about the layered ZnO nano-material. With the density functional theory （DFT） and grand canonical Monte Carlo method,the paper studies the binding of the absorption sites of ZnO sheet and a single H2 molecule and the relations between the hydrogen storage capacity and the interlayer spacing and the intensity of pressure in the interlayer of ZnO sheets at normal temperature （293 K） and at low temperature （77 K）. The results show that the binding energy at the central position of the six membered ring is 0. 259 eV and that when the interlayer spacing is 25 A and the intensity of pressure is 20 MPa, the hydrogen storage capacity of ZnO is 1. 10% and 4. 12%, respectively, at normal temperature and at the liquid nitrogen temperature. It is concluded that the layered ZnO nano-material has better hydrogen storage capacity at the liquid nitrogen temperature than at room temperature and that its hydrogen storage capacity increases with the interlayer spacing and the intensity of pressure.