Room-temperature synthesis of Prussian blue analogue Co3[Co(CN)6]2 porous nanostructures and their CO2 storage properties

Abstract

A nanosized Prussian blue analogue Co₃[Co(CN)₆]₂ (PBA) with novel morphology was achieved at room temperature by simple mixing K₃[Co(CN)₆]₂ and Co(CH₃COO)₂·4H₂O in the presence of sodium dodecylbenzenesulfonate (SDBS). The as-prepared product was 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 different surfactants on the morphology and size of the particles were investigated. The experimental results showed that the amount of SDBS employed in the reaction system played an important role in determining the size and shape of the products. More interestingly, the as-prepared product showed high CO₂ adsorption at room temperature and 1 bar of pressure, which is higher than that of the bulk materials. These results prove that the gas adsorption properties of Co₃[Co(CN)₆]₂ are highly dependent on not only its surface area but also its morphology, and the materials at the nanoscale are more favorable to adsorption applications.