We produced highly uniform nanoporous thin films of the dense array of titania (TiO2)
pores of 70~80 nm in diameter with nanoimprinting method. Titania in HCl and 2-propanol solution
was coated on an indium tin oxide (ITO) surface and embossed with an array of PMMA nanopoles
which was produced using a nanoporous alumina (Al2O3) template. Two-step anodization was
introduced to produce highly uniform and dense nanopores on the aluminum surface. The polymethyl
methacrylate (PMMA) was poured onto and infiltrated into the nanoporous alumina surface which
was heated at 150 oC. The alumina nanopores and aluminum plate were removed by wet-etching
leaving an array of PMMA nanopoles. These highly uniform nanostructured titania films will be very
useful for photovoltaic and photocatalytic applications where nanostructuring of surface with
controlled dimensions are essential.