| Autor: |
Ma L; Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, P. R. China., Chen YL; Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, P. R. China., Song XP; Department of Gastrointestinal Surgery, Xiangya Hospital, Central South University, Changsha 410008, P.R. China.; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, United States., Yang DJ; Beijing Computational Science Research Center, Beijing 100193, P. R. China., Li HX; Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, P. R. China., Ding SJ; School of Mathematics and Physics, China University of Geosciences (Wuhan), Wuhan 430074, P. R. China., Xiong L; Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, P. R. China., Qin PL; Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, P. R. China., Chen XB; Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, P. R. China. |
| Abstrakt: |
Au nanoingots, on which an Au nanosphere is accurately placed in an open Au shell, are synthesized through a controllable hydrothermal method. The prepared Au nanoingots exhibit an adjustable cavity structure, strong plasmon coupling, tunable magnetic plasmon resonance, and prominent photocatalytic and SERS performances. Au nanoingots exhibit two resonance peaks in the extinction spectrum, one (around 550 nm) is ascribed to electric dipole resonance coming from the central Au, and the other one (650-800 nm) is ascribed to the magnetic dipole resonance originating from the open Au shell. Numerical simulations verify that the intense electric and magnetic fields locate in the bowl-shaped nanogap between the Au nanosphere and shell, and they can be further optimized by changing the size of the outer Au shell. Au nanoingots with the largest shell have the strongest electric field because of large-area plasmon coupling, while Au nanoingots with the largest shell opening size have the strongest magnetic field. As a result, the structure-adjustable Au nanoingots show a high tunability and enhancement of catalytic reduction of p -nitrophenol and SERS detection of Rhodamine B. Specially, Au nanoingots with the largest shell size exhibit the highest catalytic activity and Raman signals at 532 nm excitation. However, Au nanoingots with the largest shell opening size have the highest photocatalytic activity with light irradiation (λ > 420 nm) and exhibit the best SERS performance at 785 nm excitation. |
