title: Ligand-exchange assisted formation of Au/TiO2 Schottky contact for visible-light photocatalysis.
abstract: Plasmonic noble metal nanoparticles have emerged as a promising material in sensitizing wide-bandgap semiconductors for visible-light photocatalysis. Conventional methods in constructing such heterocatalysts suffer from either poor control over the size of the metal nanoparticles or inefficient charge transfer through the metal/semiconductor interface, which limit their photocatalytic activity. To solve this problem, in this work we construct Au/TiO2 photocatalysts by depositing presynthesized colloidal Au nanoparticles with well-controlled sizes to TiO2 nanocrystals and then removing capping ligands on the Au surface through a delicately designed ligand-exchange method, which leads to close Au/TiO2 Schottky contact after a mild annealing process. Benefiting from this unique synthesis strategy, the obtained photocatalysts show superior activity to conventionally prepared photocatalysts in dye decomposition and water-reduction hydrogen production under visible-light illumination. This study not only opens up new opportunities in designing photoactive materials with high stability and enhanced performance for solar energy conversion but also provides a potential solution for the well-recognized challenge in cleaning capping ligands from the surface of colloidal catalyst nanoparticles.
authors.affiliation: Center for Materials Chemistry, Frontier Institute of Science and Technology, Xi'an Jiaotong University , Xi'an, Shaanxi 710054, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Ding
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.forename: Shengnan
authors.initials: S
authors.lastname: He
authors.forename: Chuanbo
authors.initials: C
authors.lastname: Gao
authors.forename: Yadong
authors.initials: Y
authors.lastname: Yin
mesh_terms: D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D008024:Ligands; D008027:Light; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D008024:Ligands; C009495:titanium dioxide; D006046:Gold; D006859:Hydrogen; D014025:Titanium
keywords: Schottky junction; gold nanoparticle; hydrogen production; photocatalysis; visible light