FeOOH/$TiO_2$, a heterojunction structure between FeOOH and $TiO_2$, was prepared by covering the surface of the $sim$100-nm-sized FeOOH particles with Degussa P25 by applying maleic acid as an organic linker. Under visible light irradiation (${lambda}{geq}$ 420 nm), FeOOH/$TiO_2$ showed a notable photocatalytic activity in removal of gaseous 2-propanol and evolution of $CO_2$. It was found that FeOOH reveals a profound absorption in the spectral range of 400 - 550 nm, and its valence band (VB) level is located relatively lower than that of $TiO_2$. The considerable photocatalytic efficiency of the FeOOH/$TiO_2$ under visible light irradiation was therefore deduced to be caused by the hole transfer between the VB of FeOOH and $TiO_2$.