Fabrication Of Carbon Nanomaterial Arrays On Titanium Surface For Electrochemical Applications

In recent years,the carbon nanomaterials and nanotechnologies have paved the way for the development of high performance electrochemical sensors.The structural advantages of the directional growth of one-dimensional carbon nanomaterials have large specific surface area,unique surface effect and rapid electronic transmission channel,which making the carbon nanomaterials to be the electrode materials of the new electrochemical biosensor with the excellent performance.In this paper,a one-dimensional nanostructured titania nanotube arrays?TiO₂@ NTAs?were prepared by electrochemical anodic oxidation.Then,a high performance electrochemical sensor was developed by coating a carbon layer on TiO₂ NTAs to prepara TiO₂@C NTAs with TiO₂ NTAs as template.But the tubes of the nanostructure are independent of each other and are harmful to the transmission of substances.By chemical etching,a porous structure is formed on the tubes wall of TiO₂ nanotubes and a three-dimensional nanostructure with higher electrochemical activity is developed.The main contributions of this dissertation are summerized as follows:?1?Uniform TiO₂ NTAs were fabricated by electrochemical anodization,with tube diameters ranging from 70 to 80 nm,lengths of ?8 ?m.A carbon layer was coated on TiO₂ NTAs by electrochemical deposition of Pyrrole,followed by annealing in a tube furnace under nitrogen flow.The TiO₂@C NTAs electrode exhibits a reversible voltammetric response to Fe?CN?63-/4-redox couple and can be applied to the determination of some small biological molecules such as dopamine?DA?and uric acid?UA?.The linear range of UA was 0.1-100 ?M by differential pulse voltammetry.The linear range of DA was 5-175 ?M,the detection limit was 0.19 ?M,and the sensitivity was 571.7 ?AmM^-1 cm^-2 by time current curve.?2?The porous TiN NTAs was prepared by etching TiO₂ NTAs at high temperature under NH₃ flow.A carbon layer was coated on the porous TiN NTAs by physical deposition method of dopamine,followed by annealing in a tube furnace under nitrogen flow,to prepare porous TiN@C NTAs.The porous TiN@C NTAs electrode exhibits a reversible voltammetric response to Fe?CN?63-/4-redox couple and can be applied to the determination of some small biological molecules such as dopamine?DA?and uric acid?UA?.The linear range of DA was 0.1-180.1 ?M,the detection limit was 0.07395 ?M,and the sensitivity was 555.43 ?AmM^-1 cm^-2 by time current curve.