| Titania nanotubes array attracts attention due to its high surface area and quantum efficiency. It is widely used in photocatalysis, gas sensor, photovoltage, water-splitting, solar cell, dye sensitized solar cells and water treatment. It is a potential nano material for extensive application. In this study, metal/metal oxide composite titania nanotubes array was fabricated via electrochemical deposition in two systems. The morphology was characterized, the photoelectric property and hydrogen sensitivity were investigated, and their mechanisms were also discussed.The metal (Cu, Ag, Pd) and metal oxide (CuO) composite titania nanotubes array was fabricated via the electrochemical deposition in aqueous solution and microemulsion. The results indicated that7mA/cm2is the suitable deposition current density for deposition in aqueous solution. As for microemulsion,0.05mol/L is the best concentration of metal ion in aqueous phase.Current density, time and temperature of heat treatment were supposed to be three important factors which can influence the photoelectric property effectively. By comparison, it indicates that samples with higher photoelectric response were obtained when their temperatures of heat treatment were less than200℃and Cu2O phase exists. Among these samples, those fabricated via current density of7mA/cm2and deposition time of20s have promoted property. Besides, after the modification, its interface resistance is lower while the conductivity is higher.Pd nanoparticles were loaded on titania nanotubes array under suitable conditions. The Pd and PdO nanoparticles distribute uniformly and their diameters were between5to10nm. By comparison, it indicates that the hydrogen sensitivity of composite titania nanotubes array under low temperature was much higher, which have the highest sensitivity when the temperature is75℃and the hydrogen concentration is1000ppm. |
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