催化学报 ›› 2019, Vol. 40 ›› Issue (6): 796-818.DOI: 10.1016/S1872-2067(19)63290-0

• 第十一届全国环境催化与环境材料学术会议专栏 • 上一篇    下一篇

异质/同质相结高效光催化的研究进展:以相变构建为例

杨凯a,d, 李笑笑a, 余长林a,b, 曾德彬a, 陈范云a, 张开莲a, 黄微雅a, 纪红兵c   

  1. a 江西理工大学冶金与化学工程学院, 江西赣州 341000;
    b 广东石油化工学院环境科学工程学院, 广东省石油化工污染过程与控制重点实验室, 广东茂名 525000;
    c 广东石油化工学院化学工程学院, 广东茂名 525000
  • 收稿日期:2018-11-09 修回日期:2018-12-26 出版日期:2019-06-18 发布日期:2019-04-26
  • 通讯作者: 余长林
  • 基金资助:

    国家自然科学基金(21707055,21567008,21607064);江西省5511科技创新人才(20165BCB18014);江西省主要学术与学科带头人(20172BCB22018);江西省自然科学基金(20161BAB203090,20181BAB213010,20181BAB203018);江西省教育厅青年基金(GJJ160671);福州大学国家重点实验室开放基金(SKLPEE-KF201712);江西理工大学清江优秀人才项目;江西理工大学博士启动基金.

Review on heterophase/homophase junctions for efficient photocatalysis:The case of phase transition construction

Kai Yanga,d, Xiaoxiao Lia, Changlin Yua,b, Debin Zenga, Fanyun Chena, Kailian Zhanga, Weiya Huanga, Hongbing Jic   

  1. a School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China;
    b Key Laboratory of Petrochemical Pollution Process and Control, Faculty of Environmental Science and Engineering, Maoming 525000, Guangdong, China;
    c School of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China
  • Received:2018-11-09 Revised:2018-12-26 Online:2019-06-18 Published:2019-04-26
  • Contact: S1872-2067(19)63290-0
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21707055, 21567008, 21607064), Program of Qingjiang Excellent Young Talents, Jiangxi University of Science and Technology, Program of 5511 Talents in Scientific and Technological Innovation of Jiangxi Province (20165BCB18014), Academic and Technical Leaders of the Main Disciplines in Jiangxi Province (20172BCB22018), Jiangxi Province Natural Science Foundation (20161BAB203090, 20181BAB213010, 20181BAB203018), Young Science Foundation of Jiangxi Province Education Office (GJJ160671), and Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment (SKLPEE-KF201712) in Fuzhou University.

摘要:

半导体光催化剂在环境处理和能量转换方面有着巨大的应用潜力,但由于电子-空穴对的复合作用,半导体光催化剂的光催化性能较低.相结的存在是提高电子-空穴分离效率及光催化活性的有效途径,对相结设计的深入研究是提高电荷转移性能和效率的有效手段.因此,相结光催化技术的发展,对于设计一个良好的相结和了解电子-空穴分离机理具有重要的意义.
通常,相结的构建需要特殊的制备技术以及良好的晶格匹配.纳米异质结材料结合快速转移载流子的特点,具有小尺寸效应和颗粒限域效应的优点,且具有单组分纳米材料或体相异质结不具有的独特特性.纳米晶异质结可以促进光生电子的快速转移,根据两种半导体带的相对位置,异质结可分为I型、Ⅱ型和Ⅲ型,根据不同的电子转移途径可分为p-n型和Z-型.当p型半导体(空穴为多数电荷载流子)或n型半导体(电子为多数电荷载流子)密切接触时,由于能带和其它性质的差异,会形成结,并在结的两侧形成空间电位差.空间电位差的存在可以使产生光生载流子从一个半导体能级注入到另一个半导体能级,从而促进电子和空穴的分离,提高光催化效率.以p-n结为例,当它们在这两个区域共存时,它们的边界层形成一个薄的p-n结.由于p型区空穴浓度高,n型区电子浓度高,结处存在电子和空穴的扩散现象.在p-n结边界附近形成空间电荷区,从而在结内形成强的局域电场.在结的局部电场作用下,电荷在结两端累积形成电位差,后者作为驱动力可以有效地分离光生电荷.
近年来,人们在纳米相结的设计和制备上做了大量工作以提高光催化剂活性.虽然异质结具有优良的性能,但异质结的成分和元素并不是单一的,它的形成也不是一步反应.首先,需要分别合成异质结的两个成分,反应复杂,耗时,不环保.与异质结相比,同一材料通过相变构建的结也能实现光生载流子的高效分离.同质化不需要引入其它要素,因此引起了大量关注.在相变过程中,大多数均由不同晶相的半导体形成,如锐钛矿型/金红石型TiO2,α-β相Ga2O3或六方/立方CdS.由于化学成分相同,半导体材料的能带结构不易改变.因此,对同晶材料的同质结研究较少.虽然已有几篇关于异质相结的综述论文,但通过对外部诱导相变法制备相结的回顾,仍可为读者提供有关该领域研究进展的新的认识.本文对低成本、高效率的相变思路在光催化领域中的应用进行了简要的总结,并对其在光催化领域中的应用前景进行了展望.

关键词: 相变, 相结, 光催化, 有效电子转移

Abstract:

Semiconductor photocatalysts are extensively applied in environmental treatment and energy conversion. However, one of their major disadvantages is their relatively low photocatalytic performance owing to the recombination of generated electron-hole pairs. The presence of the phase junction is an effective way to promote the photocatalytic activity by increasing the separation efficiency of the electron-hole pairs. Accordingly, extensive research has been conducted on the design of phase junctions of photocatalysts to improve their charge transfer properties and efficiencies. Therefore, for the design of an appropriate phase junction and the understanding of the mechanism of electron-hole separation, the development of the photocatalytic phase junction, including the preparation methods of the heterogeneous materials, is tremendously important and helpful. Herein, the commonly used, externally induced phase transformation fabrication techniques and the primary components of the semiconductors are reviewed. Future directions will still focus on the design and optimization of the phase junction of photocatalytic materials according to the phase transition with higher efficiencies for broadband responses and solar energy utilization. Additionally, the most popular phase transformation fabrication techniques of phase junctions are briefly reviewed from the application viewpoint.

Key words: Phase transformation, Phase junction, Photocatalysis, Efficient charge transfer