ZnO-Ag-PPy And TiO₂-Au-PANI Ternary Composites:Synthesis, Characteristic And Application

Nanomaterial is a matter composed of particles between 1 to 100 nm, which has a larger surface area, special properties and high catalytic activity, becoming one of th e focus for researchers at the 21 st century. Recently, more and more researcher paid their attention to the preparation of composite materials. They tried to complex two or more components with different properties together, which could display special characteristics. In this article, we took Zn O and Ti O2 to be the objects for the study. And we chose noble metals and polymers to complex with Zn O and Ti O2, because of their high activity under the visible light. In this way, we look forward to enhancing the activity of Zn O and Ti O2 through the synergetic effects among them. The main contents are as follows:1. A fast reaction between zinc acetate and hexamethylenetetramine was carried out to produce peanut-shaped Zn O–Ag heterostructures in ethylene glycol/water mixed solvent using Ag nanoparticles as seeds and polyvinylpyrrolidone as surfactant. The Ag nanoparticles were well-dispersed on the Zn O particles, providing them with better photocatalytic performance in the decomposition of methylene blue than the pure Zn O. Furthermore, the introduction of a layer of polypyrrole coating on the Zn O–Ag surface enhanced the catalytic activity in two ways. On one hand, polypyrrole could protect the Ag from oxidation and being lost under both UV irradiation and visible light. On the other hand, polypyrrole could prominently increase the absorption of photons under the visible light. Meanwhile, we also tested the catalytic activity of the catalysts after 4 times of recycle. And the results displayed that samples with Ag particle or polymer remained a higher activity than the single component of Zn O.2. We achieved different morphological Ti O2 particles through a simple hydrolysis reaction of Ti Cl4 in different periods of time at 30.℃. The yields of the products were different, where the flower or rob-like nanostructures displayed a highest one. Meanwhile, the synthetic time to got the follower-like product is relatively shortlived. So we chose the Ti O2 with flower-like nanostructure to be the test subject. In the composite experiment, firstly we mixed the as-prepared Ti O2 powder in ethanol with Au nanoparticles which were also dispersed in ethanol to get Ti O2-Au nanocomposite under ultrasonic. After that, a layer of PANI was synthesized through in-situ surface polymerization.