物理化学学报2018，Vol.34Issue(12)：1373-1380,8.DOI:10.3866/PKU.WHXB201804131
氧化锌有序结构在Au(111)和Cu(111)上的生长
Growth of Ordered ZnO Structures on Au(111) and Cu(111)
摘要
Abstract
The growth and structural properties of ZnO thin films on both Au(111) and Cu(111) surfaces were studied using either NO2 or O2 as oxidizing agent.The results indicate that NO2 promotes the formation of well-ordered ZnO thin films on both Au(111) and Cu(111).The stoichiometric ZnO thin films obtained on these two surfaces exhibit a flattened and non-polar ZnO(0001) structure.It is shown that on Au(111),the growth of bilayer ZnO nanostructures (NSs) is favored during the deposition of Zn in presence of NO2 at 300 K,whereas both monolayer and bilayer ZnO NSs could be observed when Zn is deposited at elevated temperatures under a NO2 atmosphere.The growth of bilayer ZnO NSs is caused by the stronger interaction between two ZnO layers than between ZnO and Au(111) surface.In contrast,the growth of monolayer ZnO NSs involves a kinetically controlled process.ZnO thin films covering the Au(111) surface exhibits a multilayer thickness,which is consistent with the growth kinetics of ZnO NSs.Besides,the use of O2 as oxidizing agent could lead to the formation of substoichiometric ZnOx structures.The growth of full layers of ZnO on Cu(111) has been a difficult task,mainly because of the interdiffusion of Zn promoted by the strong interaction between Cu and Zn and the formation of Cu surface oxides by the oxidation of Cu(111).We overcome this problem by using NO2 as oxidizing agent to form well-ordered ZnO thin films covering the Cu(111) surface.The surface of the well-ordered ZnO thin films on Cu(111) displays mainly a moiré pattern,which suggests a (3 × 3) ZnO superlattice supported on a (4 × 4) supercell of Cu(111).The observation of this superstructure provides a direct experimental evidence for the recently proposed structural model of ZnO on Cu(111),which suggests that this superstructure exhibits the minimal strain.Our studies suggested that the surface structures of ZnO thin films could change depending on the oxidation level or the oxidant used.The oxidation of Cu(111) could also become a key factor for the growth of ZnO.When Cu(111) is pre-oxidized to form copper surface oxides,the growth mode of ZnOx is altered and single-site Zn could be confined into the lattice of copper surface oxides.Our studies show that the growth of ZnO is promoted by inhibiting the diffusion of Zn into metal substrates and preventing the formation of sub-stoichiometric ZnOx.In short,the use of an atomic oxygen source is advantageous to the growth of ZnO thin films on Au(111) and Cu(111) surfaces.关键词
ZnO/Au(111)/ZnO/Cu(111)/扫描隧道显微镜/X射线光电子能谱/模型催化Key words
ZnO/Au(111)/ZnO/Cu(111)/STM/XPS/Model catalysis分类
化学化工引用本文复制引用
赵新飞,陈浩,吴昊,王睿,崔义,傅强,杨帆,包信和..氧化锌有序结构在Au(111)和Cu(111)上的生长[J].物理化学学报,2018,34(12):1373-1380,8.基金项目
科技部国家重点研发计划(2017YFB0602205,2016YFA0202803),国家自然科学基金(21473191,91545204)和国家青年千人计划资助项目 （2017YFB0602205,2016YFA0202803）
The project was supported by the Ministry of Science and Technology of China (2017YFB0602205,2016YFA0202803),the National Natural Science Foundation of China (21473191,91545204) and the Thousand Talents Program for Young Scientists （2017YFB0602205,2016YFA0202803）
