Uniform sponge-like Bi 2 SiO 5 hierarchical nanostructures were successfully prepared via a facile and template-free solvothermal method at 150°C for 6h in ethylene glycol. The product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray microanalysis (EDX), nitrogen adsorption and UV–vis diffuse reflectance spectroscopy (DRS). The as-synthesized sponge-like Bi 2 SiO 5 hierarchical nanostructures built up from loosely-packed thin nanoflakes possessed large BET surface area and pore volume. It also exhibited excellent Cr(VI) adsorption performance, demonstrating a promising application in wastewater treatment. The as-prepared sponge-like Bi 2 SiO 5 hierarchical nanostructures also showed similar optical property and band gap compared with TiO 2 , indicating that it could be used as a potential photocatalyst.