Ma Chunyan, Pang Guanglong, He Guangzhi, Li Yang, He Chi, Hao Zhengping
Department of Environmental Nano-materials, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Department of Environmental Science and Engineering, State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
J Environ Sci (China). 2016 Jan;39:77-85. doi: 10.1016/j.jes.2015.12.004. Epub 2015 Dec 30.
We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials, which were formed by layered deposition of multiple anatase TiO2 nanosheets. The Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet, including crystal steps and edges, thereby fixing the Au-TiO2 perimeter interface. Reactant transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au-TiO2 interface. The doped Au induced the formation of oxygen vacancies in the Au-TiO2 interface. Such vacancies are essential for generating active oxygen species (*O(-)) on the TiO2 surface and Ti(3+) ions in bulk TiO2. These ions can then form Ti(3+)-O(-)-Ti(4+) species, which are known to enhance the catalytic activity of formaldehyde (HCHO) oxidation. These studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials.
我们在此描述一种一步法合成Au/TiO₂纳米球材料的方法,该材料由多个锐钛矿TiO₂纳米片层状沉积形成。金纳米颗粒通过每个TiO₂纳米片中的结构缺陷(包括晶体台阶和边缘)得以稳定,从而固定了Au-TiO₂周边界面。反应物沿着这些TiO₂纳米片层之间的间隙转移,并与Au-TiO₂界面处的催化活性位点接触。掺杂的金诱导了Au-TiO₂界面处氧空位的形成。这些空位对于在TiO₂表面生成活性氧物种(*O(-))以及在块状TiO₂中生成Ti(3+)离子至关重要。然后这些离子可以形成Ti(3+)-O(-)-Ti(4+)物种,已知该物种可增强甲醛(HCHO)氧化的催化活性。这些对Au/TiO₂样品中结构和氧空位缺陷的研究为氧化物负载金材料上HCHO氧化的催化机理提供了理论基础。