Plasmonic Ag coated Zn/Ti-LDH with excellent photocatalytic activity

Publication date: 1 March 2018
Source:Applied Surface Science, Volume 433
Author(s): Yanping Zhu, Runliang Zhu, Gangqiang Zhu, Miaomiao Wang, Yannan Chen, Jianxi Zhu, Yunfei Xi, Hongping He
Nowadays, two-dimensional (2D) nanosheets, such as layered double hydroxides (LDH), have received considerable attention for their potential to meeting clean energy demand and solving environmental problems. In this work, novel and efficient photocatalysts of plasmonic Ag nanoparticles coated Zn/Ti-LDH nanosheets have been synthesized through low-temperature reduction method. The structural characteristics of the as-prepared products were investigated by a series of characteristic methods The scanning electron microscopy (SEM) and transmission electron microscope (TEM) images showed that Ag nanoparticles were distributed on the surface of Zn/Ti-LDH uniformly. The UV–vis diffuse reflectance spectra (DRS) showed that the absorbance of Ag/LDH in visible-light region enhanced markedly and presented a broad band at 500–600nm, which was resulted from the surface plasmon resonance (SPR) effect of Ag nanoparticles. The photocatalytic activities of Ag/LDH were evaluated by degradation of Rhodamine-B (RhB) and NO. The photocatalytic experiments showed that Ag/LDH had higher photocatalytic activity than that of pure LDH, and 2%Ag/LDH exhibited the highest photocatalytic activity. In addition, the 2%Ag/LDH exhibited high photochemical stability after multiple reaction runs. The obtained results from photoluminescence (PL) spectroscopic measurement and transient photocurrent (I–V) analysis both revealed the existence of Schottky barriers between LDH and Ag nanoparticles. The electron spin resonance (ESR) showed that OH were the dominant active species in the photo-degradation process. The enhanced photocatalytic performance of the composite should be ascribed to both the SPR effect of Ag nanoparticles in visible light and the Schottky barriers between LDH and Ag nanoparticles.

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