物理化学学报 >> 2016, Vol. 32 >> Issue (3): 728-736.doi: 10.3866/PKU.WHXB201511303

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三元金属硫化物-石墨相氮化碳异质结催化剂的制备及光催化性能

王彦娟,孙佳瑶,封瑞江,张健*()   

  • 收稿日期:2015-09-15 发布日期:2016-03-04
  • 通讯作者: 张健 E-mail:zhangjianlshu@163.com
  • 基金资助:
    辽宁省自然科学基金(2015020590);辽宁省普通高等学校创新创业教育改革试点专业建设项目资助

Preparation of Ternary Metal Sulfide/g-C3N4 Heterojunction Catalysts and Their Photocatalytic Activity under Visible Light

Yan-Juan WANG,Jia-Yao SUN,Rui-Jiang FENG,Jian ZHANG*()   

  • Received:2015-09-15 Published:2016-03-04
  • Contact: Jian ZHANG E-mail:zhangjianlshu@163.com
  • Supported by:
    the Natural Science Foundation of Liaoning Province, China(2015020590);Pilot Program of University of Liaoning Innovation and Education Reform, China

摘要:

以双氰胺、醋酸锌、钼酸铵、醋酸镉和硫化钠为原料,采用水热法合成了一系列Zn-Mo共掺杂CdS(Zn-Mo-CdS),并与g-C3N4组成异质结催化剂(Zn-Mo-CdS/g-C3N4)。采用X射线衍射光谱(XRD)、紫外-可见(UV-Vis)光谱、电感耦合等离子体-原子发射光谱(ICP-AES)、电化学阻抗谱(EIS)、X光电子能谱(XPS)等分析手段对制备的催化剂进行了表征。结果表明, Zn-Mo-CdS与g-C3N4之间紧密结合并形成异质结,促进界面电荷迁移,抑制光生电子-空穴对的复合。以可见光下降解染料罗丹明B (RhB)为探针反应考察了催化剂性能。结果表明, Zn-Mo-CdS/g-C3N4异质结催化剂的光催化性能与单纯g-C3N4、Zn-Mo-CdS及双金属硫化物/g-C3N4异质结催化剂相比均有大幅度提高,质量比m(Zn-Mo-CdS)/m(g-C3N4) = 4 : 1时制备的异质结催化剂表现出最大的降解速率常数,是单纯g-C3N4和Zn-Mo-CdS的30倍和10倍。不仅Zn-Mo-CdS,其他三元金属复合硫化物如Mo-Ni-CdS和Ni-Sn-CdS与g-C3N4之间也能有效构筑异质结,促进电子-空穴对的分离和催化性能提升。

关键词: g-C3N4, 三元金属硫化物, 异质结, 光催化, 有机物降解

Abstract:

A novel Zn-Mo-CdS/g-C3N4 heterojunction photocatalyst was prepared by hydrothermal posttreatment using dicyandiamide, zinc acetate, ammonium molybdate, cadmium acetate, and sodium sulfide as raw materials. X-ray diffraction (XRD), ultraviolet-visible (UV-Vis), inductively coupled plasma atomic emission (ICP-AES), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared catalysts. The results indicate that heterojunctions are formed across the g-C3N4/Zn-Mo-CdS interface, which promotes interfacial charge transfer and inhibits the recombination of electrons and holes. The activities of as-prepared catalysts were tested through the photocatalytic degradation of Rhodamine B (RhB) under visible light. The results show that the Zn-Mo-CdS/g-C3N4 heterojunction photocatalyst clearly displayed increased activity compared with single g-C3N4 and Zn-Mo-CdS. At an optimal g-C3N4 mass fraction of 20%, the as-prepared heterojunction photocatalyst displayed the highest rate constant under visible light, which was 30 and 10 times of single g-C3N4 and Zn-Mo-CdS, respectively. Not only Zn-Mo-CdS, but also Mo-Ni-CdS and Ni-Sn-CdS can form heterojunctions with g-C3N4 to promote the rate of separation of electrons and holes and improve photocatalytic activity.

Key words: Carbon nitride, Ternary metal sulfide, Heterojunction, Photocatalysis, Organic matter degradation

MSC2000: 

  • O641