催化学报 ›› 2026, Vol. 90: 197-209.DOI: 10.1016/S1872-2067(26)65190-X

• 论文 • 上一篇    下一篇

有机-无机DVA-COF@TiO2 S型异质结高选择性光催化CO2还原制备CO

高藤榞, 舒奥宇, 刘修凡*(), 吴新鹤, 王国宏*()   

  1. 湖北师范大学化学化工学院, 湖北省污染物分析与再利用技术重点实验室, 湖北黄石 435002
  • 收稿日期:2026-01-25 接受日期:2026-03-20 出版日期:2026-11-18 发布日期:2026-09-09
  • 通讯作者: *电子信箱: neo_lxf@outlook.com (刘修凡),
    wanggh2003@163.com (王国宏).
  • 基金资助:
    国家自然科学基金(22075072);国家自然科学基金(22578106);国家自然科学基金(22302061);湖北省自然科学基金(2023AFB465)

Organic-inorganic DVA-COF@TiO2 S-scheme heterojunction for highly selective photocatalytic reduction of CO2 to CO

Tengyuan Gao, Aoyu Shu, Xiufan Liu*(), Xinhe Wu, Guohong Wang*()   

  1. Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, Hubei, China
  • Received:2026-01-25 Accepted:2026-03-20 Online:2026-11-18 Published:2026-09-09
  • Contact: *E-mail:neo_lxf@outlook.com(X. Liu),wanggh2003@163.com(G. Wang).
  • Supported by:
    National Natural Science Foundation of China(22075072);National Natural Science Foundation of China(22578106);National Natural Science Foundation of China(22302061);Natural Science Foundation of Hubei Province of China(2023AFB465)

摘要:

近年来, 化石能源的过度消耗引发了严重的能源短缺与温室效应问题. 半导体光催化技术被认为是将CO2转化为高附加值燃料的极具前景的绿色转化技术. 共价有机框架(COFs)凭借其大的比表面积、良好的界面相容性以及可调控的带隙结构, 成为CO2光催化还原领域极具潜力的候选材料. 然而, 单一COFs光催化剂的光生载流子复合速率快、团聚严重, 这极大地限制了其光催化性能的提升. 在众多改性策略中, 构建S型异质结是一种能有效提升载流子分离效率的策略. 然而, 传统无机-无机异质结界面接触不紧密, 导致界面处的载流子传输速率慢, 从而限制了光催化性能的提升. 因此, 充分利用COFs的界面特性, 开发具有紧密异质结界面的有机-无机S型异质结光催化剂至关重要.

本文基于S型异质结构建策略, 采用室温溶剂蒸发法结合低温水热法, 成功将TiO2纳米颗粒原位沉积在DVA-COF纳米微球表面, 构建了一系列DVA-COF@TiO2 S型异质结光催化剂(DVATx), 并系统探究了TiO2负载量对催化剂微结构与性能的影响. 扫描电镜和透射电镜等表征证实了TiO2纳米颗粒均匀负载于DVA-COF纳米微球表面并形成紧密的异质结界面, 并且TiO2纳米颗粒间的纳米孔为CO2还原反应提供了必要的气体扩散路径. 与纯TiO2 (6.14 μmol g-1 h-1, CO选择性: 69.87%)和DVA-COF(4.21 μmol g-1 h-1, CO选择性: 74.35%)相比, 最优配比的DVA-COF@TiO2 (DVAT200)S型异质结光催化剂表现出增强的光催化CO2还原速率(12.46 μmol g-1 h-1)与CO选择性(92.22%). 光电化学测试表明, 异质结的瞬时光电流密度高于纯TiO2和DVA-COF, 表明光催化剂的电荷分离效率得到显著提升. 此外, DVAT200的光电阻抗均低于纯TiO2和DVA-COF, 表明无机-有机界面极大地降低了电荷传输阻力. 通过原位光照X-射线光电子能谱、电子顺磁共振、飞秒瞬态吸收光谱测试, 结合密度泛函理论计算, 证明了S型电荷传输机制是DVA-COF@TiO2 S型异质结光催化CO2还原性能提升的主要原因. 原位漫反射傅里叶变换红外光谱与密度泛函理论自由能计算揭示了: (1)在光催化CO2还原过程中, 异质结的DVA-COF组分为主要的吸附与反应位点; (2)反应过程中, COOH*的形成能垒显著降低, 并且促进了CO*的脱附, 表明DVA-COF@TiO2异质结的构建成功抑制了CO*进一步加氢生成CH4, 实现了高选择性还原制备CO.

综上, 本文为有机-无机S型异质结光催化剂的设计与制备提供了新的实验思路与理论依据, 明确了COFs@TiO2异质结的界面调控与电荷转移规律对CO2还原选择性的影响机制. 为高选择性光催化CO2还原制备CO提供了新的见解, 有望推动人工光催化技术在碳减排与新能源开发领域的实际应用.

关键词: DVA-共价有机框架, TiO2, S型异质结, 光催化, CO2还原, 机理

Abstract:

Photocatalytic reduction of CO2 to produce high-value-added hydrocarbon fuels is expected to solve the severe predicament of energy shortage and the environmental governance challenges. Here, in-situ growth strategy is applied to couple TiO2 nanoparticles with spherical covalent organic framework (DVA-COF) to form a DVA-COF@TiO2 S-scheme heterojunction photocatalyst for CO2 reduction. The as-prepared DVA-COF@TiO2 S-scheme photocatalyst exhibited the enhanced photocatalytic CO2 reduction rate (12.46 μmol g-1 h-1) and CO selectivity (92.22%). The S-scheme charge transfer mechanism was investigated by in-situ irradiated X-ray photoelectron spectroscopy, electron paramagnetic resonance, density functional theory calculation, and femtosecond transient absorption spectroscopy. In-situ diffuse reflectance Fourier transform infrared spectroscopy and free energy calculations have unveiled the process of photocatalytic CO2 reduction and the reasons of the improved CO product selectivity of the heterojunction photocatalysts. This study provides a critical theoretical reference for the development of the novel organic-inorganic S-scheme heterojunction photocatalysts with higher CO selectivity, which is expected to inject strong power into the practical application of sustainable artificial photosynthesis technology.

Key words: DVA-covalent organic frameworks, TiO2, S-scheme heterojunction, Photocatalytic, CO2 reduction, Mechanism