Research On The Catalytic Performance Based On Au@Cu₂O

In recent years, elaborated control of the material crystal surface has been a research hotspot for improving the performance of materials. At present, modern life requirement about the material properties is becoming higher and higher, and single material has been not able to meet our needs. How to design the material structure based on material surface and interface of fine regulation will be effective way to explore the high performance materials.The paper regarded Cu₂O as matrix material and started from the crystal surface control. On one hand, we realized the Au@Cu₂O core-shell assembly and the photo-catalytic performance optimization from the structure. On the other hand, through the control of surface morphology of Cu₂O,we realized the interface control of crystal plane, and further enhanced the photo-catalytic performance. Finally, Au@Cu₂O/ZnO tri-complexes were prepared. The synergistic effect was explored among structure control, surface enhancement and reinforcement of tri-complexes. And its photo-catalytic and thermal catalytic performance was studied. The main work and research results were present as follows:（1） Firstly, the different morphologies of Au@Cu₂O core shell catalysts were prepared. The surface of the octahedron sample exposed eight {111} facets, but truncated octahedron surface exposed {110} facets. The results showed that the effect of adsorption and photo-catalytic performance of truncated octahedronAu@Cu₂O were stronger. The role of gold nanorods had the following two aspects: Schottky barrier and plasma resonance. The former encouraged the electron transfer from the semiconductor to metal, while the latter could promote semiconductor electron hole separation, both of which could significantly improve the photo-catalytic properties of semiconductor. Mechanism of photo-catalytic results showed that light excited electrons of Cu₂O undergone DET and PIRET two processes, which promoted the separation of electron hole pairs and then promoted the photo-catalytic performance. At the same time, Cu₂O{110} was easier to absorb the dye than {111}, so as to improve the catalytic performance.（2）Based on the part of above experiment, we performed a Cu₂O shell size adjustment experiment, to make full use of the plasma resonance effect of Au rod and optimize the photo-catalytic properties of Au@Cu₂O core-shell structure. Changing the volume of the Au nanorods could continuously adjust the size of the Cu₂O shell. Photo-catalytic experimental results showed that the catalytic performance of 97nm-Au@Cu₂Owas highest. Reducing of the shell size brought about Au rod plasma effect enhancement to promote the photo-catalytic. However, when size was further reduced, Cu₂O lost regular crystal surface. The catalytic effect crystal plane should disappear and thus reveal low photo-catalytic performance. The active species trapping experiment results showed that the hole and the resultant hydroxyl free radical were the main active species involved in the photo-catalytic process.（3） In order to obtain the catalysts with low cost and high efficiency,Au@Cu₂O/ZnO tri-complexes were prepared. The experimental results showed that 5%-Au@Cu₂O composites revealed the best photo-catalytic performance. The synergistic effect was explored among structure control, surface enhancement and reinforcement of tri-complexes. In addition, thermal catalytic effect of this material was studied.The paper designed Au@Cu₂O and Au@Cu₂O/ZnO composite catalyst, and explored the synergies effect of the structure control, crystal plane control and composite reinforcing. The photo-catalytic performance of Cu₂O materials was greatly enhanced. The research provided some new experimental basis and research ideas for the further design of new multifunctional materials.