Thickness-determined photocatalytic performance of bismuth tungstate nanosheets
By Hu, Tingxia and Li, Haiping and Zhang, Renjie and Du, Na and Hou, Wanguo
Published in RSC Adv.
The Royal Society of Chemistry
2016
Abstract
Bismuth tungstate (Bi2WO6) nanosheets with dominant exposed (010) facets and various thicknesses (H) and lateral sizes were hydrothermally synthesized via pH adjustment of precursor suspensions. As the pH increases from <1 to 8, the resultant nanosheets exhibit improved crystallinity and photoabsorption, decreased specific surface area, increased H, and decreased photoactivity in the degradation of rhodamine B (RhB), methylene blue (MB), and Eosin Y (EY) under visible light irradiation. The photoactivity of the Bi2WO6 sample obtained at pH < 1 is about 6, 100, and 25 times of that at pH 8 for RhB, MB, and EY degradation, respectively. The photoactivity enhancement is ascribed to reduction of the H. The photocatalytic efficiencies are inversely proportional to the reduction of H2 when the nanosheets can be penetrated by incident light. This work reveals the structure-performance relationship of Bi2WO6 nanosheets and provides significant guidance for preparation of high efficient two-dimensional photocatalysts.