The Surface Enhanced Raman Spectroscopy And Electrochemical Property Of Copper And Its Oxides

Copper and its oxides have broad applications prospects in areas like electronic devices and new energy technologies due to the good characteristic in photoelectronic,thermology and mechanics,which attracted many researches in various fields for a long time.This work mainly focus on the shape-controled synthesis and surface enhanced raman scattering（SERS）performance of copper nanoflower and the electrochemical property of hollow Cu₂O served as an anode material for lithium ion batteries.The specific contents are described as below:1.The synthesis and the growth mechanism of copper nanoflower.The morphology of the copper flower was manipulate via adjusting the concentration of surfactant and reductant,as well as the reaction time.As the results showed:the surfactant can regulate the surface free energy of the（100）plane by controlling the concentration to control the reaction dynamics,herein,the deposition of copper atoms on this plane is affected from edge to face,so that the morphology of copper can be tuned.In case of the adjustment of reducant,as the concentration of reductant increased,the reductive rate is speeded up,hence,the morphology and the size is affect.The observation of the morphology in different reaction time suggests that the growth of the copper flower is developed via the well-known Ostwald ripening.2.Research on the SERS activity of the copper nanoflower and the enhancement mechanism.The SERS test is carried out on the copper nanoflower obtained with variety of concentration of surfactant.The result shows that the sword-like copper nanoflower owned the highest SERS activity,whose SERS enhancement factor reached as high as 5×10⁶ which is capable to applied in single molecule detection.3.Research on the SERS mechanism of the copper nanoflower.The electric field distribution of sword is simulated via COMSOL software to explore the enhancement mechanism,and the result demonstrate dramatically enhanced electric field on the tips and the gaps of Cu swords,which mainly contribute to the excellent SERS performance of the Cu sword-like crystals.4.Synthesis and the electrochemical property of hollow Cu₂O nanocrystal.The hollow Cu₂O nanocrystal is prepared via wet chemistry method with uniform morphology and size.Besides,the electrochemical performance of hollow Cu₂O nanocrystal is also tested by assembling CR2032 coin cell,using CT 4008 battery test system and CHI760E electrochemical workstation.The first discharge capacity reaches as high as 1089.7 mAh/g at a current density of 500 mA/g.And it still retained reversible capacity of 327.09 mAh/g after 200 cycles,which is 5.5 times higher than that of spherical Cu₂O nanocrystal under same conditions reported before,which showed good cycle stability.The result indicated that hollow structure is able to improve cycle and structural stability ascribe to the ability to reduce mechanical volume expansion during the charge-discharge process,so as to improve the property of LIBs by using Cu₂O as anode material.5.The electrochemical performance of carbon coated hollow Cu₂O nanocrystal which prepared via chemical vapour deposition（CVD）method.The results shows that the coverage uniformity of carbon on the surface of hollow Cu₂O nanocrystal varies with the catalytic temperature.The research result shows that the Cu₂O/C owns improved charge-discharge property and performs better cyclying stability.