Study On Electrochemical Sensor Based On Graphene/Palladium Nanoparticles

Graphene is a kind of carbonaceous material which is tightly packed into a single two-dimensional honeycomb lattice structure with carbon atoms. The thickness of graphite crystal film is only 0.335 run. It not only has the character of ultrathin, super strong and strong electrical conductivity, but also has electrical, thermal and mechanical properties. Graphene oxide is a kind of important derivative of graphene, and its structure is approximately similar to graphene. The different between graphene and graphene oxide is that the surface of graphene oxide contain of some oxygen-containing functional groups, such as:hydroxyl, carboxyl, carbonyl and epoxy group etc. what’s more, the zero-dimensional graphene quantum dots is a special type of carbon materials below 10 nm. So graphen quantum dots show strong quantum confined effect and boundary effect and it has a potential application prospects in light-emitting diodes, photovoltaic devices, biological medicine, sensors and many other fields. What’s more, fullerenes is one kind of carbon materials. This paper combine graphene oxide, fullerenes, graphene quantum dots and palladium nanoparticles respectively to get new materials. Then the new material is used to detect formic acid and ethanol by electrochemical detection.The first chapter:introduces the preparation methods, characterization methods and applications in many aspects of graphene, graphene quantum dots and palladium nanoparticles. And this chapter introduces the background of this paper, the main research contents and innovation points briefly.The second chapter:combines graphene oxide and palladium nanoparticles to get new material of graphene oxide-palladium nanomaterials. The material is analyzed by transmission electron microscopy, infrared spectroscopy and electrochemical characterization. Finally the material is used to modify glassy carbon electrode surface through the method of drop-coating and used for detection of formic acid and ethanol. The experimental results show that during the certain concentration range, the linear equation of formic acid is Ip(A)=1.991×10-5+4.325×10-3C(M), R2= 0.9802, and the linear range is 5 ×10-4～10-2mol/L; linear equation for ethanol is Ip(A)= 2.634×10-5+0.01106C (M), R2=0.9904, and the linear range is 5×10-4～10-2 mol/L.The third chapter:introduces the synthesis of graphene quantum dots and graphene quantum dots palladium nanomaterials. Then the new material is analyzed by transmission electron microscopy, infrared spectrum and electrochemical properties. The graphene quantum dots palladium nano-material is used for the electrochemical detection of formic acid and ethanol. The experiment results show that the modified glassy carbon electrode using graphene quantum dots palladium nanomaterials has the certain recognition function of formic acid and ethanol. The experiment lay some theoretical basis for building the sensors of formic acid or ethanol.The fourth chapter:Synthesis of fullerenes palladium nanomaterials, and the new material is analyzed by the transmission electron microscopy and electrochemical characterization. Then the fullerenes palladium nano-materials is used for the electrochemical catalytic oxidation of methane.