Preparation of Self-Assembled Spherical g-C3N4/tz-Bi0.92Gd0.08VO4 Heterojunctions and Their Mineralization Properties

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• 作者：Chengcheng Zhao ; Guoqiang Tan ; Jing Huang ; Wei Yang ; Huijun Ren ; Ao Xia
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：November 4, 2015
• 年：2015
• 卷：7
• 期：43
• 页码：23949-23957
• 全文大小：581K
• ISSN：1944-8252

文摘

A novel kind of spherical g-C₃N₄/tz-Bi_0.92Gd_0.08VO₄ heterojuctions are prepared via a simple microwave hydrothermal method. The sphere self-assembled mechanism and the heterojunction photocatalytic mechanism are mainly studied in this article. The results show that the added g-C₃N₄ sheets first anchor on ms-BiVO₄ surfaces and then polymerize to form the coating layers, generating steric effect which is competing with Gd³⁺ induction effect to affect the crystal transformation (from ms-BiVO₄ to tz-BiVO₄) and its growth during those processes. Afterward, independent coated structures are further polymerized and assembled into g-C₃N₄/tz-Bi_0.92Gd_0.08VO₄ spheres. Because E_CB (鈭?.95 V) of g-C₃N₄ is more negative than E_CB (鈭?.05 V) of tz-BiVO₄, the photoelectrons of g-C₃N₄ can be transferred into tz-BiVO₄ surfaces through the heterojunction structure, so as to promote the separation rate of electron鈥揾ole pairs. In general, the adding of g-C₃N₄ can introduce hydroxyl groups to catch the photoholes and can inject electrons to react with dissolved oxygen to boost the production of active groups. Depending on such an orderly cooperation, g-C₃N₄/tz-Bi_0.92Gd_0.08VO₄ heterojunction catalysts exhibit high and stable mineralization properties.