Prussian Blue Analogue (PBA) Mn(3)[Co(CN)(6)](2)·nH(2)O porous nanocubes were successfully synthesized in high yield at room temperature in the presence of poly(vinylpyrrolidone) (PVP) and characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The effects of synthetic parameters such as surfactant, the ratio of different solvents on the morphology and size of the particles were investigated. The experimental results showed that poly(vinylpyrrolidone) (PVP) and solvent ethanol play critical roles in the formation of uniform porous nanocubes. N(2) adsorption properties indicated that the Mn(3)[Co(CN)(6)](2) porous nanocubes with an average diameter of 240 nm possessed a high surface area of 675 m(2) g(-1) with total volume of 0.354 cm(3) g(-1). Moreover, the porous nanocubes showed high CO(2) adsorption at room temperature and 1 bar of pressure. To our knowledge, this is the first report on the synthesis of Mn(3)[Co(CN)(6)](2) nanomaterials and their CO(2) adsorption applications at the nanoscale.