Effects of pH on the Hierarchical Structures and Photocatalytic Performance of BiVO4 Powders Prepared via the Microwave Hydrothermal Method

详细信息    查看全文

• 作者：Guoqiang Tan ; Lili Zhang ; Huijun Ren ; Shasha Wei ; Jing Huang ; Ao Xia
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2013
• 出版时间：June 12, 2013
• 年：2013
• 卷：5
• 期：11
• 页码：5186-5193
• 全文大小：615K
• 年卷期：v.5,no.11(June 12, 2013)
• ISSN：1944-8252

文摘

BiVO₄ powders with hierarchical structures were prepared by the microwave hydrothermal method at different pHs, using Bi(NO₃)₃路5H₂O and NH₄VO₃ as raw materials. The results show that, when the pH value of the precursor is 0.59, the as-prepared powders are monoclinic BiVO₄ crystals with octahedron and decahedron morphologies. Spherical and polyhedral BiVO₄ with particle sizes in the range of 2鈥? 渭m can be prepared under the strong acid condition (pH = 0.70鈥?.21) and possess a mixed crystal consisting of tetragonal and monoclinic phases, whereas rodlike and dendritic BiVO₄ with a pure monoclinic phase can be obtained within a very wide pH range (pH = 4.26鈥?.76). The phase transformation from tetragonal phase to monoclinic phase occurs at pH 3.65. At pH >9.76, the powders are the nonstoichiometric crystals between the mixed-phase BiVO₄ and non-BiVO₄. The photocatalytic efficiencies were evaluated by the degradation of Rhodamine B (RhB) under UV and simulated sunlight irradiation. The corresponding relationship among pH values of the precursor, crystalline phase, morphology, and photocatalytic performance of the powders was also discussed.

Keywords:

BiVO₄; pH value; hierarchical structure; microwave hydrothermal method; photocatalysis