Critical Temperature for Fabrication of Ti Metal Electrode Produced by Alkali, Acid and Heat Treatment in N2 Gas

It is important for the fuel cell electrodes to show high total surface area, electrical conductivity and ability for catalyst fixation on the surface.On the other hand titanium oxide is useful as an electrode for fuel cell, solar cell, or electrolysis of water, since it can fix catalyst, dye and enzyme on its surface.In the present study, titanium (Ti) metal was chemically and thermally treated to form nano structure with high specific surface area, conductivity, scratch resistance and ability for catalyst fixation on its surface.Ti metal electrode with nano-network structure composed of titanium nitrides, titanium oxynitride and titanium oxide on its surface was prepared by NaOH and HCl solution treatments and subsequent heat treatments in N 2 gas.The effect of the temperature of heat treatment in N 2 gas on the structure, total surface area and conductivity of the Ti metal surface were studied.The fine network structure with high total surface area was formed on the surfaces of the Ti metal heated at 600°C to 1000°C.However, it was partially densified over 900°C.The electrical conductivity became higher with increasing temperature of the heat treatment because of the formation of the highly conductive titanium nitrides and oxygen deficient titanium oxide.Consequently, the highly conductive Ti metal electrode without reducing its total surface area could be prepared, when it was heated at 850°C.A redox catalyst could be fixed on the treated titanium metal surface.