CAJ | 학술논문

采用平面波超软赝势方法研究了立方相Ag3 PO4(111)面的表面能和表面原子弛豫结构．首先对Ag3 PO4(111)面的八种不同原子终止结构的体系总能量进行计算,结果表明B种表面模型被证实为最稳定的(111)面原子几何结构．针对该表面结构,探讨了表面能和原子弛豫与模型中原子层数和真空厚度的关系,当原子层数为24层,真空厚度为0．6 nm时,表面能收敛于1．41 J/m2( LDA-CAPZ)和1．39 J/m2(GGA-PBE)．表面原子弛豫后,表面两个三配位的Ag原子均向里移动,超过0．06 nm,而表面次层的O原子则均向外移动约0．0042 nm,导致弛豫后暴露在最表面的是O原子,同时表面原子的核外电子向表面内部发生转移,结构趋于稳定．这些结果为进一步深入研究Ag3 PO4表面的光催化活性起源提供理论支持．
채용평면파초연안세방법연구료립방상Ag3 PO4(111)면적표면능화표면원자이예결구．수선대Ag3 PO4(111)면적팔충불동원자종지결구적체계총능량진행계산,결과표명B충표면모형피증실위최은정적(111)면원자궤하결구．침대해표면결구,탐토료표면능화원자이예여모형중원자층수화진공후도적관계,당원자층수위24층,진공후도위0．6 nm시,표면능수렴우1．41 J/m2( LDA-CAPZ)화1．39 J/m2(GGA-PBE)．표면원자이예후,표면량개삼배위적Ag원자균향리이동,초과0．06 nm,이표면차층적O원자칙균향외이동약0．0042 nm,도치이예후폭로재최표면적시O원자,동시표면원자적핵외전자향표면내부발생전이,결구추우은정．저사결과위진일보심입연구Ag3 PO4표면적광최화활성기원제공이론지지．
First-principles calculations based on the plane-wave ultrasoft pseudopotential method have been taken to investigate the surface energy and structure of cubic Ag3 PO4 ( 111 ) surface. There are eight different structures of cubic Ag3 PO4 (111) surface because different atoms are terminated on the surface layers. The cal-culated results show that the B model is much more stable than other seven structures. By investigating the effect of variable vacuum width and slab thickness on the surface energies and surface atomic displacements, the sur-face energies are converged to 1. 41 J/m2 ( LDA-CAPZ) and 1. 39 J/m2 ( GGA-PBE) for slab thickness of 24-atom layers and vacuum width of 0. 6 nm. At last, by the atomic relaxation of surface structure, the two three-fold coordinated Ag atoms are inward relaxation of more 0. 06 nm, and three O atoms in sublayer are outward re-laxation of about 0. 0042 nm. So O atoms are exposed to the outermost surface, while part of electrons upon O at-oms transfer from the surface to internal atoms, the structure becomes more stable. This study serves as an initial and important step toward more in-depth analysis of the photocatalytic activity origin of Ag3 PO4 surface.