Photochemical Synthesis Of Gold Nanorods Based Composites

Gold nanorods(Au NRs)have special optical,electrical,photothermal,chemical and biological properties and have important applications in the fields of biology,chemistry,medicine,physics and microelectronics.The further introduction of a second metal or metal oxide can adjust its performance.Therefore,the development of new green and convenient method to prepare nanorod composite structures has attracted wide attention.Local surface plasmon resonance(LSPR)effect is a very important property of Au NRs,which could cause special magnetic,photoelectric and thermal effects after irradiation..However,how to use this effect to build Au NRs oxide composite structure and special morphological research is still lacking.In response to this problem,this thesis proposes to obtain specific metal oxides and metal nanostructures based on the LSPR effect,study the preparation process conditions and formation mechanism.The following research progress have been made:(1)Based on the LSPR effect of gold nanorods,Au NRs/Mn O₂composite nanostructures were successfully prepared.The main process is to use photogenerated electrons to reduce KMn O₄to Mn O₂,and the photogenerated holes are oxidized by sacrificial reagents to supplement the electrons.The above process is affected by factors such as the light source,the amount and concentration of KMn O₄and sacrificial reagents.Au NRs can be oxidized by KMn O₄,which shortens the nanorods.Proper illumination,KMn O₄concentration and sacrificial reagents can avoid this change.When the light source was cut to 700 nm,methanol was used as the sacrificial reagent,the content and concentration of KMn O₄is at 150?L and0.01M,a good Au NRs/Mn O₂composite structure was obtained.(2)Based on the LSPR effect,a dandelion flower-like nanocomposite structure was achieved.The effects of light source,the amount of HAu Cl₄and additives on the formation process of dandelion flower-like Au composite structure were systematically studied,and the effects of the above factors on the formation of flower-like nanostructure were discussed.It was found that the light source has a great influence on the structure of dandelion flower-like nanocomposites.When the light source is greater than 700 nm,a good dandelion flower-like nanocomposite structure can be formed.At the same time,the additives was also found important.Methanol and ethanol as additives can only form chain structures or dumbbell-shaped structures,while only isopropyl alcohol could get the dandelion flower-like nanocomposites.The results show thatmetal oxides and metal nanostructures with specific structures can be obtained by designing and optimizing the reaction conditions based on the LSPR effect of gold nanorods.The method has outstanding advantages like mild reaction conditions,simple controllability and free of surfactant.The outcome of this work can provide new ideas for the photochemical synthesis of specific nanostructures.