Modification of one-dimensional TiO2 nanotubes with CaO dopants for high CO2 adsorption

Abstract

One-dimensional calcium oxide (CaO-) based titanium dioxide (TiO 2) nanotubes were successfully synthesized through a rapid electrochemical anodization and chemical wet impregnation techniques. In this study, calcium nitrate solution was used as a calcium source precursor. The reaction time and concentration of calcium source on the formation of CaO-TiO2 nanotubes were investigated using field emission microscopy, energy dispersion X-ray spectroscopy, and X-ray diffraction. The adsorption capacity of CO2 was determined by thermal gravimetric analyzer. A maximum of 4.45 mmol/g was achieved from the CaO-TiO2 nanotubes (6.64 at% of Ca). The finding was attributed to the higher active surface area for CaO to adsorb more CO2 gas and then formed CaCO3 compound during cyclic carbonation-calcination reaction. © 2014 Chin Wei Lai.