Preparation And Electrochemical Applications Of Gold Nanoparticles And Platinum Nanoparticles Modified Electrode

All the research work presented here includes electrochemical studies with some important biomolecules and organic molecules and these studies are based on gold nanoparticle arrays modified on some specific conductive substrates and heterostructure platinum nanoparticles on the AuNPs/ITO.Gold nanoparticles,which were prepared by electroplating or wet chemical reduction method,platinum nanoparticles which were prepared by electrodeposition in this research work and possess good performance for electrochemical catalysis.they were used in the study of electrochemical detection,electrochemical catalysis.The main research works are as follows:(1)the dopamine(DA)is a neurotransmitter which plays an irreplaceable role in the human central nervous system.It exists in human blood.The high concentration or too low concentration of DA will have an effect on the body function.Uric acid(UA)is the indispensable material in the human body for the normal operation of the human body function.Because the oxidation potential of the them is very close,the electrode surface which require be modified was used for testing as the detection electrode.Here,The AuNPs/ITO electrode was made by electrodepositing of Au.The author immersed the electrode in the solution including L-Cysteine,finally got the L-Cys SAMs/AuNPs/ITO electrode.Then the electrodes were used for detection of dopamine in the presence of UA.Relatively,the L-Cys SAMs/AuNPs/ITO electrode prepared by chronoamperometry-CV method can meet the demand of electrochemical detection of the dopamine and uric acid at the same time.Moreover,both the peak current densities of the dopamine and uric acid have good linear relationships with their concentrations within a certain range.(2)Methanol is an important resource for direct fuel cell research because of its advantages such as simple molecular structure,easy to get,safety for storage and transportation.Platinum is widely used as catalytic material for its unique electrocatalytic ability with methanol oxidation.But the intermediate,CO,generated in methanol oxidation process can make the platinum poisoning and its catalytic activity decreasing.However the existence of gold can make the poisoned platinum catalyst regenerate.The PtNPs/AuNPs/ITO electrode was made by electrodepositing of platinum on a gold-nanoparticles-modified ITO electrode.Electrocatalyticoxidation reactions of methanol on the as-prepared platinum coating gold-nanoparticles-modified ITO electrode were carried out.The surface nanoparticles of the PtNPs/AuNPs/ITO electrode is heterostructure,heterostructure materials is beneficial to improve the catalytic performance of the electrode.The electrodepositing parameters were optimized and the good electrocatalytic performance of the PtNPs/AuNPs/ITO electrode obtained here is better than the AuNPs/ITO electrode without platinum.The as-prepared PtNPs/AuNPs/ITO electrode has good ability to resist poisoning,stable electrocatalytic oxidation performance.