Transforming Photocatalytic g‐C3N4/MoSe2 into a Direct Z‐Scheme System via Boron‐Doping: A Hybrid DFT Study
Transforming Photocatalytic g‐C3N4/MoSe2 into a Direct Z‐Scheme System via Boron‐Doping: A Hybrid DFT Study
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通过硼掺杂将光催化 g-C3N4/MoSe2 转化为直接 Z-方案系统：混合 DFT 研究
DOI：
10.1002/cssc.202001048
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发表时间：
2020
期刊：
影响因子：
8.4
通讯作者：
Cai‐Zhuang Wang
中科院分区：
文献类型：
--
作者：
Changzhi Ai;Jin Li;Liang Yang;Zhipeng Wang;Zhao Wang;Yamei Zeng;Rong Deng;Shiwei Lin;Cai‐Zhuang Wang
Z-方案光催化系统是一种理想的能带排列结构，因为光生载流子的分离效率高，同时保持了电子的强还原活性和空穴的氧化活性。然而，Z方案光催化剂的设计和构造是具有挑战性的，因为需要适当的能带对准和内置电场。在这里，我们提出了一种新的方法，Z-计划光催化系统使用密度泛函理论计算与HSE 06混合功能。通过对g-C3 N4进行硼掺杂（B-掺杂的C3 N4/MoSe 2），将不期望的I型g-C3 N4/MoSe 2异质结转化为直接Z-方案系统。详细分析了B掺杂的C3 N4/MoSe 2异质结的总态密度和分态密度、功函数和微分电荷密度分布，结果表明，在界面处存在适当的能带排列和内建电场，方向为从g-C3 N4到MoSe 2，证明了直接Z-方案异质结。对吸收光谱的进一步研究表明，硼掺杂后的光吸收效率大大提高。结果一致证实，电子结构和光催化性能可以有效地操纵由一个简单的硼掺杂。以这种方式调节异质结的能带排列为高效异质结基光催化系统的合理设计提供了有价值的见解。
Z‐scheme photocatalytic systems are an ideal band alignment structure for photocatalysis because of the high separation efficiency of photo‐induced carriers while simultaneously preserving the strong reduction activity of electrons and oxidation activity of holes. However, the design and construction of Z‐scheme photocatalysts is challenging because of the need for appropriate energy band alignment and built‐in electric field. Here, we propose a novel approach to a Z‐scheme photocatalytic system using density functional theory calculations with the HSE06 hybrid functional. The undesirable type‐I g‐C3N4/MoSe2heterojunction is transformed into a direct Z‐scheme system through boron doping of g‐C3N4(B‐doped C3N4/MoSe2). Detailed analysis of the total and partial density of states, work functions and differential charge density distribution of the B‐doped C3N4/MoSe2heterojunction shows the proper band alignment and existence of a built‐in electric field at the interface, with the direction from g‐C3N4to MoSe2, demonstrating a direct Z‐scheme heterojunction. Further investigation on the absorption spectra reveals a large enhancement of the light absorption efficiency after boron doping. The results consistently confirm that electronic structures and photocatalytic performance can be effectively manipulated by a facile boron doping. Modulating the band alignment of heterojunctions in this way provides valuable insights for the rational design of highly efficient heterojunction‐based photocatalytic systems.