Jiang Denghui, Zhou Wei, Zhong Xinhua, Zhang Yuegang, Li Xinheng
The Laboratory for Nano-Catalytic Materials and Technologies and ∥i-Lab, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences , Suzhou 215123, China.
ACS Appl Mater Interfaces. 2014 Jul 23;6(14):10958-62. doi: 10.1021/am5023978. Epub 2014 Jul 3.
The surface plasmon resonance (SPR) and Schottky effects are important photocatalytic activity boosters in metallic cocatalyst/photocatalyst systems, but it is difficult to differentiate them. In this report, we design a simple method to distinguish the two effects by utilizing a distance-tunable self-assembled monolayer (SAM) in a gold (Au)-Cu2O composite in conjunction with UV and visible-light sources, by which we had only the SPR or Schottky effect identified in the visible or UV light, respectively. Cysteine (cys) and mercaptoundecanoic acid (MUA) SAMs as linkers were used respectively for making Au-cys-Cu2O and Au-MUA-Cu2O composites. Au-citrate-Cu2O as a mild linker was also synthesized. Under UV-light irradiation, Au-Cu2O showed only the Schottky effect, while Au-MUA-Cu2O and Au-cys-Cu2O showed neither of the two effects. Under visible-light irradiation, Au-MUA-Cu2O and Au-cys-Cu2O showed clearly only the localized SPR (LSPR) effect, while Au-Cu2O demonstrated the coexistence of the two effects, which was further confirmed by their LSPR enhancement factor.
表面等离子体共振（SPR）和肖特基效应是金属助催化剂/光催化剂体系中重要的光催化活性增强剂，但很难区分它们。在本报告中，我们设计了一种简单的方法来区分这两种效应，即在金（Au）-氧化亚铜（Cu2O）复合材料中利用距离可调的自组装单分子层（SAM）结合紫外光和可见光光源，通过这种方法我们分别在可见光或紫外光下仅识别出SPR或肖特基效应。分别使用半胱氨酸（cys）和巯基十一烷酸（MUA）单分子层作为连接体来制备Au-cys-Cu2O和Au-MUA-Cu2O复合材料。还合成了作为温和连接体的柠檬酸金-氧化亚铜（Au-citrate-Cu2O）。在紫外光照射下，Au-Cu2O仅表现出肖特基效应，而Au-MUA-Cu2O和Au-cys-Cu2O均未表现出这两种效应。在可见光照射下，Au-MUA-Cu2O和Au-cys-Cu2O仅明显表现出局域表面等离子体共振（LSPR）效应，而Au-Cu2O则表现出两种效应的共存，这通过它们的LSPR增强因子得到了进一步证实。
