Synthesis And Electrochemical Properties Of Ordered Nanoporous Film

In this dissertation, a series of ordered nanoporous transferable films have been synthesized via electrodeposition technology. Based on these experiments and characteristics of material itself, we built various thin film devices with order nanoporous on them. The electrochemical properties of these films have also been investigated. The results showed that based on simple synthetic process, these ordered nanoporous films have potentials in future nanodevices and nanotechnology. The main works are displayed as follows:（1） The AAO templates were homemade by a twice anodic oxidation process. In this work, the anodization was carried out at 50 V in 0.3 mol/L oxalic acid electrolyte. As a result, the distance between two adjacent channels in the templates would be about 120 nm and the diameter of channels would be about 70 nm. Then, a thin Au layer of about 30 nm in thickness was sputtered onto the top side of the template to serve as conductive electrode. Then ordered porous Fe₂O₃/Au films were fabricated by electrodeposition and the following low-temperature oxidation process. After dissolve the support of AAO template, the Fe₂O₃/Au film could be transferred onto ITO glass through floating-transfer method, building a non-enzymatic AA sensor. SEM images showed that the as-prepared porous film is arranged in an ordered pores array. The period distance of the adjacent pores is about 120 nm, while the average diameter of pores is about 50 nm. The porous film is mountain-shaped, with ups and downs on the surface, leading to a highly rough and loose surface topography. XRD, TEM and SAED indicated that Fe₂O₃ porous film appears to be polycrystalline. It exhibited excellent electrocatalytic performance to AA with a high sensitivity of 1281.9 μA mM-1 cm-2, a wide linear range of 25 μM to 10 mM, and a low detection limit of 1 μM. The satisfactory results obtained indicated that the proposed sensor was promising for the development of a novel strategy for AA detection.（2） The ordered porous PtFe/Au films were fabricated by AAO template-assisted electrodeposition. After dissolve the support of AAO template, the Pt Fe /Au film could be transferred onto ITO glass through floating-transfer method, building a catalyst for methanol. The electrochemical measurements in alkaline medium showed that the nanoporous Pt Fe/Au film exhibited higher catalytic activity toward methanol oxidation reaction, with a high oxidation peak current density（59.0m A/cm2）, much higher than ordered nanoporous Pt/Au film（10.9mA/cm-2） and plane PtFe/Au film（2.87 m A/cm-2）. These results indicated that the particular porous structure and the alloying contribution of Fe and Pt have important effect on catalytic activity.（3） Based on AAO template, the ordered porous NiO/Au films were fabricated by electrodeposition and the following oxidation process. After dissolve the support of AAO template, the NiO/Au film could be transferred onto ITO glass through floating-transfer method, building an electrochemical capacitor. The electrochemical measurements in alkaline medium showed that the nanoporous NiO/Au film is an excellent electrochemical capacitor. The specific capacitance of NiO /Au is as high as 8.8×102 F/cm3 at current of 0.02 mA and fell 1.4 percent of the initial value after 100 cycles of constant current charge/discharge process, indicated that this film exhibits well electrochemical performance.