催化学报 ›› 2022, Vol. 43 ›› Issue (10): 2592-2605.DOI: 10.1016/S1872-2067(22)64094-4

• 论文 • 上一篇    下一篇

采用共价有机骨架(COF)和g-C3N4纳米片构筑2D/2D S型异质结并用于高效光催化析氢

董鹏玉a,, 张艾彩珺b,, 程婷c, 潘劲康b, 宋骏a, 张磊a, 关荣锋a, 奚新国c,*(), 张金龙d,#()   

  1. a盐城工学院, 江苏省新型环保重点实验室, 江苏盐城 224051
    b盐城工学院化学化工学院, 江苏盐城 224051
    c盐城工学院材料科学与工程学院, 江苏省生态环境材料重点实验室, 江苏盐城 224051
    d华东理工大学化学与分子工程学院, 上海多介质环境催化与资源化工程技术研究中心, 上海 200237
  • 收稿日期:2022-01-17 接受日期:2022-03-08 出版日期:2022-10-18 发布日期:2022-09-30
  • 通讯作者: 奚新国,张金龙
  • 作者简介:共同第一作者.
  • 基金资助:
    国家自然科学基金(51772258);国家自然科学基金(21403184);国家自然科学基金(21972040);国家自然科学基金(21878257);江苏省“青蓝工程”项目;江苏省研究生科研与实践创新项目(KYCX21_3147);上海市教委创新计划项目(2021-01-07-00-02-E00106);江苏省高等学校优秀科技创新团队;江苏省自然科学基金(BK20191024);上海市科学技术委员会(20DZ2250400)

2D/2D S-scheme heterojunction with a covalent organic framework and g-C3N4 nanosheets for highly efficient photocatalytic H2 evolution

Pengyu Donga,, Aicaijun Zhangb,, Ting Chengc, Jinkang Panb, Jun Songa, Lei Zhanga, Rongfeng Guana, Xinguo Xic,*(), Jinlong Zhangd,#()   

  1. aKey Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China
    bSchool of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China
    cKey Laboratory for Ecological-Environment Materials of Jiangsu Province, School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China
    dKey Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, Shanghai Engineering Research Center for Multi-media Environmental Catalysis and Resource Utilization, East China University of Science and Technology, Shanghai 200237, China
  • Received:2022-01-17 Accepted:2022-03-08 Online:2022-10-18 Published:2022-09-30
  • Contact: Xinguo Xi, Jinlong Zhang
  • About author:Contributed equally to this work.
  • Supported by:
    National Natural Science Foundation of China(51772258);National Natural Science Foundation of China(21403184);National Natural Science Foundation of China(21972040);National Natural Science Foundation of China(21878257);Qinglan Project of Jiangsu Province;Scientific Research and Practical Innovation Project for Graduate Students in Jiangsu Province(KYCX21_3147);Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-02-E00106);Outstanding Scientific and Technological Innovation Team of Universities of Jiangsu Province;Natural Science Foundation of Jiangsu Province(BK20191024);Science and Technology Commission of Shanghai Municipality(20DZ2250400)

摘要:

作为一种清洁能源, 氢能因具有洁净、高热值、高效率和环境友好等特点, 而被认为是解决能源危机和环境问题的最理想的替代能源之一. 近年来, 利用太阳能光催化分解水析氢受到了人们的广泛关注, 开发高效的光催化剂成为研究重点. 构建具有良好界面接触、更快光生电荷转移效率以及高氧化还原能力的S型异质结被认为是提高光催化析氢性能的最有效途径之一.

本文制备了具有较高化学稳定性的β-酮烯胺基TpPa-1-COF纳米片, 并通过在乙二醇中超声剥离得到的g-C3N4纳米片(g-C3N4 NS), 再将它们各自的纳米片分散液混合后经过油浴加热回流处理, 由于TpPa-1-COF纳米片与g-C3N4纳米片两相之间的π-π共轭相互作用, 制得了一种独特的二维/二维(2D/2D) S型异质结TpPa-1-COF NS/g-C3N4 NS(TPCNNS)光催化剂. 为了比较, 通过物理混合的方法制备了TpPa-1-COF NS与g-C3N4 NS的混合物(TPCNNS-pm), 并制备了块体β-酮烯胺基TpPa-1-COF/块体g-C3N4复合材料(TPCN). 实验发现, 具有S型异质结的TpPa-1-COF NS与g-C3N4 NS之间表现出紧密的界面接触, 形成了π-π共轭异质界面. 稳态光致发光光谱(PL)、瞬态PL衰减谱、光电流-时间响应图和电化学阻抗谱结果表明, 相比于TPCNNS-pm和TPCN, TPCNNS样品表现出明显增强的光生载流子分离和转移效率, 这主要是由于2D/2D结构导致的π-π共轭异质界面极大地促进了光生电荷分离. 密度泛函理论计算表明, TpPa-1-COF和g-C3N4具有不同的功函数, 较大的功函数差值产生了较大的费米能级能量差, 这导致界面处的能带发生了向上/向下弯曲; 差分电荷密度分析表明, 基态条件下在π-π共轭异质界面区域中g-C3N4的界面电荷自发向TpPa-1-COF转移导致了内建电场的形成. 这种强的内建电场可以有效地驱动电荷定向迁移, 对于电荷的分离和利用具有很大帮助. 由于内建电场显著促进了载流子的分离和迁移, 导致在可见光照射下, 具有最佳复合比例的TPCNNS-2(TpPa-1-COF:g-C3N4 NS质量比为2:1)样品的光催化析氢速率(1153 μmol g-1 h-1)比纯TpPa-1-COF NS和g-C3N4 NS分别提高了2.8和5.6倍, 而且表现出良好的光催化稳定性. 另外, 通过DMPO自由基捕获实验证实了在可见光照射下TpPa-1-COF NS不能产生超氧阴离子自由基(O2-), 而TPCNNS-2样品却表现出明显的O2-信号, 进一步从实验上验证了2D/2D TpPa-1-COF NS/g-C3N4 NS异质结光生电荷的分离和迁移遵循S型机制. 总之, 本文为开发具有高效析氢性能的π-π共轭2D/2D COF基S型光催化异质结材料提供了新思路.

关键词: 共价有机框架材料, g-C3N4, π-π共轭, 2D/2D材料, S型异质结, 光催化析氢

Abstract:

The fabrication of S-scheme heterojunctions with fast charge transfer and good interface contacts, such as intermolecular π-π interactions, is a promising approach to improve photocatalytic performance. A unique two-dimensional/two-dimensional (2D/2D) S-scheme heterojunction containing TpPa-1-COF/g-C3N4 nanosheets (denoted as TPCNNS) was developed. The established maximum interfacial interaction between TpPa-1-COF NS and g-C3N4 NS may result in a π-π conjugated heterointerface. Furthermore, the difference in the work functions of TpPa-1-COF and g-C3N4 results in a large Fermi level gap, leading to upward/downward band edge bending. The spontaneous interfacial charge transfer from g-C3N4 to TpPa-1-COF at the π-π conjugated interface area results in the presence of a built-in electric field, according to the charge density difference analysis based on density functional theory calculations. Such an enhanced built-in electric field can efficiently drive directional charge migration via the S-scheme mechanism, which enhances charge separation and utilization. Thus, an approximately 2.8 and 5.6 times increase in the photocatalytic hydrogen evolution rate was recorded in TPCNNS-2 (1153 μmol g-1 h-1) compared to pristine TpPa-1-COF and g-C3N4 NS, respectively, under visible light irradiation. Overall, this work opens new avenues in the fabrication of 2D/2D π-π conjugated S-scheme heterojunction photocatalysts with highly efficient hydrogen evolution performance.

Key words: Covalent organic framework, g-C3N4, π-π, Conjugated, 2D/2D material, S-Scheme heterojunction, Photocatalytic hydrogen evolution