物理化学学报 >> 2017, Vol. 33 >> Issue (5): 941-948.doi: 10.3866/PKU.WHXB201702085

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Ag3XO4(X = P,As,V)电子结构及光催化性质的第一性原理计算

李蛟1,2,*(),陈忠2   

  1. 1 山东理工大学材料科学与工程学院,山东淄博255049
    2 南洋理工大学材料科学与工程学院,新加坡639798
  • 收稿日期:2016-12-05 发布日期:2017-04-20
  • 通讯作者: 李蛟 E-mail:haiyan9943@163.com
  • 基金资助:
    山东省高等学校科技发展计划(J15LA08)

First-Principles Study on the Electronic and Photocatalytic Properties of Ag3XO4 (X = P, As, V)

Jiao LI1,2,*(),Zhong CHEN2   

  1. 1 School of Materials Science and Engineering, Shandong University of Technology, Zibo 255049, Shandong Province, P. R. China
    2 School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
  • Received:2016-12-05 Published:2017-04-20
  • Contact: Jiao LI E-mail:haiyan9943@163.com
  • Supported by:
    the College Technology Development Project of Shandong Province, China(J15LA08)

摘要:

基于密度泛函理论的第一性原理对Ag3XO4(X = P,As,V)电子结构及光催化性质进行了对比研究。与Ag3PO4相比,Ag3VO4较好的光催化稳定性主要源于其结构中Ag―O间较强的作用力增加了对Ag+的控制,而Ag3VO4弱的光催化活性与其导带底中存在d轨道成份以及较低的价带边势(2.335 V,vs NHE)有关;对Ag3AsO4而言,其优于Ag3PO4光催化活性的原因基于三个方面:(1)由高分散Ag s-Ag s杂化轨道构成的导带底能带;(2)窄的带隙(1.91 eV);(3)宽的可见光响应范围以及高的光吸收系数。此外,Ag3XO4(X = P,As,V)均为间接带隙半导体光催化材料,其中,Ag3VO4有用于分解水制氢研究的可能;上述计算结果与实验结果吻合。

关键词: 第一性原理, Ag3XO4(X = P,As,V), 能带结构, 态密度, 光催化

Abstract:

In this study, the electronic structures and photocatalytic properties of Ag3XO4 (X = P, As, V) were investigated using the first principles based on the density functional theory. In comparison to Ag3PO4, Ag3VO4 shows better photocatalytic stability, mainly due to the enhanced Ag―O bonds and improved Ag ion stability, but poorer photocatalytic activity in the visible light region mainly due to the presence of d orbital character at the conduction band minimum (CBM) and lower valence band maximum (VBM) potentials (2.335 V, vs NHE). Ag3AsO4 shows photocatalytic activity superior to Ag3PO4, which may be attributed to the following reasons: (1) the highly dispersive band structure of the CBM resulting fromAg s-Ag s hybridization, (2) a smaller band gap of 1.91 eV, (3) the broader absorption range and higher absorption capacity of visible light. Moreover, our theoretical results demonstrate that though Ag3XO4 (X = P, As, V) species act as indirect band gap photocatalytic semiconductors, only Ag3VO4 is a potential candidate for the photocatalytic hydrogen generation from water. The calculated results mentioned above are in good agreement with experimental results.

Key words: First principles calculations, Ag3XO4 (X = P, As, V), Band structure, Density of states, Photocatalytic property

MSC2000: 

  • O641