物理化学学报 >> 2021, Vol. 37 >> Issue (8): 2009102.doi: 10.3866/PKU.WHXB202009102

所属专题: 二维光催化材料

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非贵金属助剂Ni2P修饰类石墨碳氮化物光催化剂增强可见光光催化产氢性能

张鹏1,2, 王继全1,*(), 李源2, 姜丽莎2, 王壮壮2, 张高科2,*()   

  1. 1 湖北省工程咨询股份有限公司,武汉 430061
    2 武汉理工大学资源与环境工程学院,武汉 430070
  • 收稿日期:2020-09-29 录用日期:2020-10-28 发布日期:2020-11-02
  • 通讯作者: 王继全,张高科 E-mail:441780131@qq.com;gkzhang@whut.edu.cn
  • 基金资助:
    国家自然科学基金(51472194);湖北省自然科学基金(2016CFA078)

Non-Noble-Metallic Cocatalyst Ni2P Nanoparticles Modified Graphite-Like Carbonitride with Enhanced Photocatalytic Hydrogen Evolution under Visible Light Irradiation

Peng Zhang1,2, Jiquan Wang1,*(), Yuan Li2, Lisha Jiang2, Zhuangzhuang Wang2, Gaoke Zhang2,*()   

  1. 1 Hubei Province Engineering Consulting Co, Ltd., Wuhan 430061, China
    2 School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China
  • Received:2020-09-29 Accepted:2020-10-28 Published:2020-11-02
  • Contact: Jiquan Wang,Gaoke Zhang E-mail:441780131@qq.com;gkzhang@whut.edu.cn
  • About author:Email: gkzhang@whut.edu.cn (G.Z.)
    Email: 441780131@qq.com (J.W.)
  • Supported by:
    the National Natural Science Founding of China(51472194);the National Science Funding of Hubei Province, China(2016CFA078)

摘要:

随着化石燃料的日益枯竭,能源危机已经成为一个严重的全球性问题。开发氢气等环境友好型的可再生能源来替代化石燃料已迫在眉睫。光催化水解制氢被认为是解决这一问题最有效的技术之一,贵金属(如Pt)可以作为助催化剂提高光催化体系的制氢性能,但高昂的成本限制了该技术的进一步应用。因此,开发新型、高性能、低成本的非贵金属助催化剂以替代贵金属助催化剂,对于将光催化产氢技术付诸实践具有重要意义。在此,我们以共轭聚合物(SCN)n为前驱体成功地合成了Ni2P/类石墨碳氮化物光催化剂(Ni2P/CN),在可见光照射下具有优异的光催化产氢性能。使用各种表征技术、光学和光电化学测试研究了这些材料的结构组成、形貌特征以及光学性质。X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)和X射线光电子能谱(XPS)结果表明了合成的Ni2P/CN纳米复合材料具有良好的晶体结构。扫描电镜(SEM)和透射电镜(TEM)结果显示,Ni2P/CN样品具有典型的二维层状结构,Ni2P纳米颗粒均匀地负载在CN表面。紫外-可见漫反射光谱(DRS)结果表明,负载Ni2P纳米颗粒有效地增强了CN对可见光的吸收能力。光致发光光谱(PL)和光电流测试结果表明,Ni2P的负载有利于促进光生载流子的迁移和分离效率。光催化产氢实验是在可见光照射下进行的,以三乙醇胺为牺牲剂。结果表明,Ni2P/CN复合光催化剂具有良好的光催化还原性能。性能最优的Ni2P/CN复合材料产氢效率达到了623.77 μmol·h-1·g-1,优于以贵金属Pt作助催化剂的CN样品的产氢效率(524.63 μmol·h-1·g-1)。此外,通过一系列表征、光学以及光电化学测试的分析表明,Ni2P纳米粒子均匀地附着在CN的表面上,并且它们之间存在很强的界面效应,从而形成了抑制光生载流子重组并促进电子迁移的电子传输通道,促进电子从CN迁移至Ni2P。此外,根据实验和表征,提出了一种可能的光催化机理。这项工作对于非贵金属取代贵金属作为光催化产氢助剂的发展具有重要意义。

关键词: 助催化剂, Ni2P, 光催化产氢, 界面效应, 可见光

Abstract:

Energy crisis has become a serious global issue due to the increasing depletion of fossil fuels; therefore, it is crucial to develop environmentally friendly and renewable energy resources, such as hydrogen (H2), to replace fossil fuels. From this viewpoint, photocatalytic H2 production is considered as one of the most promising technologies. Noble metal platinum (Pt) can be applied as an efficient cocatalyst for improving the H2 production performance of photocatalytic systems; however, its high cost limits its further application. Thus, the development of novel, high-activity, and low-cost cocatalysts for replacing noble metal cocatalysts is of great significance for use in photocatalytic H2 evolution techniques. Herein, we successfully synthesized a Ni2P/graphite-like carbonitride photocatalyst (Ni2P/CN) using a conjugated polymer (SCN)n as precursor for enhanced photocatalytic H2 production under visible light illumination. Various characterization techniques, including optical and photoelectronic chemical tests, were used to investigate the structural composition, morphology, and light adsorption ability of these materials. X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy results showed that Ni2P/CN nanocomposites with good crystal structure were obtained. Scanning electron microscopy and transmission electron microscopy results revealed that the Ni2P/CN samples had a typical two-dimensional layered structure, and the Ni2P nanoparticles were uniformly loaded on the surface of the CN to form a non-noble metal promoter. UV-Vis diffuse reflectance spectra results demonstrated that the loading of Ni2P nanoparticles effectively enhances the adsorption capacity of CN to visible light. Photoluminescence spectroscopy and photocurrent (PL) results suggested that Ni2P loading to CN is beneficial for promoting the migration and separation efficiency of photogenerated carriers. Photocatalytic H2 production was conducted under visible light irradiation with triethanolamine as a sacrificial agent. The results suggest that the Ni2P/CN composite photocatalysts exhibit excellent photocatalytic reduction performance. In particular, the H2 evolution rate of the optimal Ni2P/CN nanocomposite is 623.77 μmol·h-1·g-1, which is higher than that of CN modified by noble metal Pt, i.e., 524.63 μmol·h-1·g-1. In conclusion, Ni2P nanoparticles are homogeneously attached to the surface of CN, and a strong interfacial effect exists between them, thereby forming an electron transfer tunnel that greatly inhibits the recombination of photoinduced carriers and promotes the migration of electrons from CN to Ni2P. In addition, a possible photocatalytic mechanism is proposed based on the experiments and characterizations. This work has profound significance for developing non-noble metal cocatalysts for the substitution of noble metal cocatalysts for high-efficiency photocatalytic H2 evolution.

Key words: Cocatalyst, Ni2P, Photocatalytic hydrogen evolution, Interfacial effect, Visible light

MSC2000: 

  • O643