One-dimensional hierarchical Bi2WO6 hollow tubes with porous walls: synthesis and photocatalytic property

Abstract

One-dimensional hierarchical Bi₂WO₆ hollow tubes with porous walls have been solvothermally synthesized using Bi₂O₃ rods as both template and reactant, and characterized by FESEM, TEM and XRD. Experimental results indicate that the walls of these micro-tubes are made of Bi₂WO₆ nanoplates stacking in a disordered state, which creates an interesting macro-mesoporous structure. Influencing factors on the resulting products including the adding order of reactants, ethanol content, and pH value are systematically investigated. A possible mechanism based on the Kirkendall effect is proposed. What is more, in comparison with commercial TiO₂ powders (P25) the hierarchical Bi₂WO₆ hollow tube structure exhibits a superior shape-associated photocatalytic activity in degrading RhB under simulated sunlight irradiation. The high photocatalytic performance can be attributed to the novel hierarchical structure, which enables good permeability, large BET surface areas, and proper energy band. Moreover, the employed “sacrificial template” method can be extended to the synthesis of other Bi-based photocatalysts successfully.