物理化学学报 >> 2020, Vol. 36 >> Issue (3): 1905080.doi: 10.3866/PKU.WHXB201905080

所属专题: 光催化剂

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非金属掺杂石墨相氮化碳光催化的研究进展与展望

王亦清,沈少华*()   

  • 收稿日期:2019-05-28 录用日期:2019-07-15 发布日期:2019-07-19
  • 通讯作者: 沈少华 E-mail:shshen_xjtu@mail.xjtu.edu.cn
  • 作者简介:Shaohua Shen is currently a full professor at Xi'an Jiaotong University, China. He obtained his Ph.D. degree in thermal engineering in 2010 from Xi'an Jiaotong University. During 2008–2009 and 2011–2012, he worked as a guest researcher at Lawrence Berkeley National Laboratory and a postdoctoral researcher at the University of California at Berkeley. His research interests include photocatalytic and photoelectrochemical solar energy conversion
  • 基金资助:
    国家自然科学基金(21875183);国家自然科学基金(51672210);国家自然科学基金(51888103)

Progress and Prospects of Non-Metal Doped Graphitic Carbon Nitride for Improved Photocatalytic Performances

Yiqing Wang,Shaohua Shen*()   

  • Received:2019-05-28 Accepted:2019-07-15 Published:2019-07-19
  • Contact: Shaohua Shen E-mail:shshen_xjtu@mail.xjtu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21875183);the National Natural Science Foundation of China(51672210);the National Natural Science Foundation of China(51888103)

摘要:

自从Fujishima和Honda利用TiO2光阳极和Pt电极成功实现太阳能光电化学分解水之后,光催化被认为是解决环境污染和能源短缺两大问题最有前景的方法之一,因为该技术可以有效的利用太阳能这种地球上最丰富的能源来驱动多种不同的催化反应实现能源生产和环境净化,比如:水分解、CO2还原、有机污染物降解和有机合成等。除了金属氧化物、金属硫化物和金属氮氧化物等多类金属化合物半导体光催化剂,近几年,石墨相氮化碳(g-C3N4)因其原料来源广泛、无毒、稳定以及相对较窄的带隙(2.7 eV)而具备可见光响应等特点,在光催化领域获得了广泛的重视。然而,g-C3N4对太阳光谱中可见光的吸收效率较低且光生电子和空穴复合严重,导致其光催化活性处于较低水平。至今,研究人员已经开发出多种提高g-C3N4光催化活性的方法,如元素掺杂、微纳结构和异质结构设计和助催化剂修饰等。元素掺杂被证明是调节g-C3N4独特电子结构和分子结构的有效方法,可以大幅扩展其光响应范围,并促进光生电荷分离。特别地是,非金属元素掺杂以提高g-C3N4的光催化活性已经得到很好的研究。通常用于掺杂g-C3N4的非金属元素是氧(O)、磷(P)、硫(S)、硼(B)、卤素(F、Cl、Br、I)和其他非金属元素(如碳(C)和氮(N)自掺杂),因为这些非金属元素有着易于获取的原材料并可以较为简单的引入g-C3N4骨架结构中。在这篇综述文章中,作者首先介绍了g-C3N4的结构和光学性质,接着简要介绍了光催化剂的g-C3N4的改性;然后详细回顾了非金属掺杂改善g-C3N4光催化活性的进展,同时总结了光催化机理以期更好地理解光催化的本质并指导新型g-C3N4光催化剂的开发。最后,对g-C3N4光催化剂的后续研究进行了展望。

关键词: 石墨相氮化碳(g-C3N4), 非金属掺杂, 光催化, 能带结构, 电子结构

Abstract:

Since Fujishima and Honda demonstrated the photoelectrochemical water splitting on TiO2 photoanode and Pt counter electrode, photocatalysis has been considered as one of the most promising technologies for solving both the problems of environmental pollution and energy shortage. This process can effectively use solar energy, the most abundant energy resource on the earth, to drive various catalytic reactions, such as water splitting, CO2 reduction, organic pollutant degradation, and organic synthesis, for energy generation and environmental purification. Except for the various metal-based semiconductors, such as metal oxides, metal sulfides, and metal oxynitrides, developed for photocatalysis, graphitic carbon nitride (g-C3N4) has attracted significant attention in the recent years because of its earth abundancy, non-toxicity, good stability, and relatively narrow band gap (2.7 eV) for visible light response. However, g-C3N4 suffers from insufficient absorption of visible light in the solar spectrum and rapid recombination of photogenerated electrons and holes, thus resulting in low photocatalytic activity. Until now, various strategies have been developed to enhance the photocatalytic activity of g-C3N4, including element doping, nanostructure and heterostructure design, and co-catalyst decoration. Among these methods, element doping has been found to be very effective for adjusting the unique electronic and molecular structures of g-C3N4, which could significantly expand the range of photoresponse under visible light and improve the charge separation. Especially, non-metal doping has been well investigated frequently to improve the photocatalytic activity of g-C3N4. The non-metal dopants commonly used for the doping of g-C3N4 include oxygen (O), phosphorus (P), sulfur (S), boron (B), and halogen (F, Cl, Br, I) and also carbon (C) and nitrogen (N) (for self-doping), as they are easily accessible and can be introduced into the g-C3N4 framework through different physical and chemical synthetic methods. In this review article, the structural and optical properties of g-C3N4 is introduced first, followed by a brief introduction to the modification of g-C3N4 as photocatalysts. Then, the progress in the non-metal doped g-C3N4 with improved photocatalytic activity is reviewed in detail, with the photocatalytic mechanisms presented for easy understanding of the fundamentals of photocatalysis and for guiding in the design of novel g-C3N4 photocatalysts. Finally, the prospects of the modification of g-C3N4 for further advances in photocatalysis is presented.

Key words: Graphitic carbon nitride (g-C3N4), Non-metal doping, Photocatalysis, Band structure, Electronic structure

MSC2000: 

  • O643