Hollow Sodium Tungsten Bronze (Na0.15WO3) Nanospheres: Preparation, Characterization, and Their Adsorption Properties

We report herein a facile method for the preparation of sodium tungsten bronzes hollow nanospheres using hydrogen gas bubbles as reactant for chemical reduction of tungstate to tungsten and as template for the formation of hollow nanospheres at the same time. The chemical composition and the crystalline state of the as-prepared hollow Na0.15WO3 nanospheres were characterized complementarily, and the hollow structure formation mechanism was proposed. The hollow Na0.15WO3 nanospheres showed large Brunauer-Emment-Teller specific area (33.8 m(2) g(-1)), strong resistance to acids, and excellent ability to remove organic molecules such as dye and proteins from aqueous solutions. These illustrate that the hollow nanospheres of Na0.15WO3 should be a useful adsorbent.