作　　者： (陈小雨）; (岳远霞）; (冯庆）;

机构地区： 重庆师范大学物理与电子工程学院,重庆401331

出　　处： 《原子与分子物理学报》 2017年第4期786-792,共7页

摘　　要： 采用基于密度泛函理论(DFT-D)体系下的第一性原理平面波超软赝势方法,研究了被不同非金属(B、C、N、F)掺杂的TiO_2(101)表面吸附NH_3的特性与作用机理.研究发现:被非金属掺杂后的表面对NH_3的吸附效果要优于未掺杂表面.不同元素掺杂对比发现:C掺杂后的表面吸附能最大,稳定后吸附距离最小,为最稳定吸附结构.通过Mulliken电荷分布和分态密度的分析,得到了不同吸附条件下NH_3在TiO_2掺杂表面的催化氧化还原作用机理,并发现各模型吸附能的不同是由于掺杂(X)位原子与NH_3分子的相互作用强弱不同所造成.掺杂原子在费米面附近的电子态密度贡献越强,掺杂原子与NH_3分子电荷转移的净值越小,吸附距离越小,吸附能越大,吸附更稳定. Based on density functional theory（ DFT- D） system under the primary principle of plane wave super soft constraint potential method, this paper studied the characteristics and mechanism of the different nonmetal （B ,C ,N ,F） doped titanium dioxide （101） surface adsorbed NH3. Results show that NH3 adsorption effect of the surface doped nonmetal is better than that of a clean surface. The surface doped C is the most stable adsorption structure by comparison with different elements doping. The analysis of Mulliken charge distribution and differ- ence charge density showed the catalytic oxidation mechanism in different TiO2 surface adsorbed NH3. The re- search found interaction strength between the doping atom and NH3 molecular lead to different adsorption energy. Near the Fermi surface, the greater contribution of the doping atoms to the electronic density of states, the smaller the charge transfer net value of doped atoms and NH3 molecule, the smaller adsorption distance, the greater the adsorption energy, and the adsorption structure is more stable.

关 键 词： 密度泛函理论 锐钛矿 表面掺杂 表面吸附