A DFT study of gas molecules adsorption on the anatase (0Â 0Â 1) nanotube arrays

► Anatase (0 0 1) TiO2 nanotube arrays have been constructed first time. ► Gas adsorption on the confined hydrophilic TiO2 nanotube arrays were investigated. ► The adsorption energies of gas molecules are influenced by the confinement. ► Electronic properties of TiO2 nanotube arrays can be modified by the adsorbed O2, NO and NO2.