Magnesium silicate double-walled hollow nanofibers (MSHNFs) with a hierarchical nanostructure have been successfully fabricated by combining the electrospinning technique with a hydrothermal method. The as-prepared MSHNFs are composed of numerous ultrathin nanosheets with a thickness of approximately 10nm and have a high specific surface area (632.2m(2)g(-1)) and large pore volume (0.92cm(3)g(-1)). The MSHNFs exhibit high adsorption capacity and excellent stability in a purification test with organic molecules and a solution of heavy-metal ions. Moreover, the MSHNFs can be easily separated from solution by gravitational sedimentation owing to their unique structure.