La(OH)3 Hollow Nanostructures with Trapezohedron Morphologies Using a New Kirkendall Diffusion Couple

A highly symmetric trapezohedron of lanthanum glycolate precursor is converted to hollow La(OH)(3) with the same morphology via a simple hydrothermal treatment of the lanthanum glycolate precursor in an alkaline solution. The formation process of the hollow structure is the result of the Kirkendall effect, in which a new diffusion couple, water and lanthanum glycolate, is proposed. This expands the scope of the Kirkendall effect in material fabrication. The hollow La(OH)(3) trapezohedron can be further converted into hollow La2O3 material by calcinations. The as-prepared La(OH)(3) hollow trapezohedron shows excellent ability to remove certain organic pollutants in wastewater.