RESUMO
Well aligned TiO2 nanotube arrays have been synthesized via anodization in an NH4F and ethylene glycol electrolyte; the resulting carbon-entrained films were treated by oxygen and argon microwave plasma. It was found that as-prepared amorphous TiO2 nanotubes can be easily crystallized into anatase at temperature lower than 150 degrees C. Carbon can be effectively eliminated in oxygen plasma and a new secondary porosity was emerged. It was found such a porous film has obvious photovoltaic and hydrogen production enhancement under simulated solar irradiation compared with that crystallized in inert argon plasma. This phenomenon may be attributed to the improvement of light adsorption and its excellent capability of hole-electron separation derives from highly ordered nanoporous configurations.
RESUMO
TiO2 nanotube array films were prepared by in-situ liquid phase transformation and deposition of anodic aluminum oxidation template films with (NH4)2TiF6 dilute solution; and the (Er, La, N)-codoped films were fabricated by impregnation with rare earth elements of Er and La following by heat treatment in flow ammonia. Obviously enhanced photocatalytic degradation of organic dye was obtained by codoped TiO2 under visible light irradiation compared with undoped TiO2 film, and the increase of photocatalytic performance of as-prepared TiO2 was attributed to the enlargement of light absorbency ranging from upconversed UV to red-shifted visible light up to 600 nm.
