催化学报 ›› 2026, Vol. 85: 153-167.DOI: 10.1016/S1872-2067(26)65022-X

• 论文 • 上一篇    下一篇

缺陷介导的Zn-CuInS2双位点协同催化: 轨道调控实现高效光催化CO2转化制乙烯

赖可溱a, 孙雨鑫a, 李林萍a, 施晓庆a, 周小松c, 李宁a, 高旸钦a,b, 戈磊a,b()   

  1. a 中国石油大学(北京)新能源与材料学院, 重质油加工国家重点实验室, 北京 102249
    b 东营国安化工有限公司, 山东东营 257400
    c 岭南师范学院化学化工学院, 广东湛江 524048
  • 收稿日期:2025-09-08 接受日期:2025-12-10 出版日期:2026-06-18 发布日期:2026-05-18
  • 通讯作者: *电子信箱: gelei08@sina.com/gelei@cup.edu.cn (戈磊).
  • 基金资助:
    国家自然科学基金(52473327);国家自然科学基金(51572295);国家自然科学基金(21273285);国家重点研发计划(2021YFA1501300);国家重点研发计划(2019YFC1907602)

Defect-mediated dual-site synergy in Zn-CuInS2 enables orbital-tailored high performance photocatalytic CO2-to-ethylene conversion

Kezhen Laia, Yuxin Suna, Linping Lia, Xiaoqing Shia, Xiaosong Zhouc, Ning Lia, Yangqin Gaoa,b, Lei Gea,b()   

  1. a State Key Laboratory of Heavy Oil Processing, College of New Energy and Materials, China University of Petroleum Beijing, Beijing 102249, China
    b Dongying Guoan Chemical Co., Ltd, Circular Economy Industrial Park, Dongying 257400, Shandong, China
    c School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang 524048, Guangdong, China
  • Received:2025-09-08 Accepted:2025-12-10 Online:2026-06-18 Published:2026-05-18
  • Contact: *E-mail: gelei08@sina.com/gelei@cup.edu.cn (L. Ge).
  • Supported by:
    National Natural Science Foundation of China(52473327);National Natural Science Foundation of China(51572295);National Natural Science Foundation of China(21273285);National Key R&D Program of China(2021YFA1501300);National Key R&D Program of China(2019YFC1907602)

摘要:

利用光催化技术将二氧化碳(CO2)转化为高附加值燃料, 是实现碳中和目标的关键路径之一. 在众多产物中, 乙烯(C2H4)等C2产物因其工业应用价值而备受关注. 但该过程面临着CO2分子难以活化, 多电子转移动力学过程缓慢, 以及C-C偶合能垒高等诸多挑战. 传统的催化剂因活性位点结构单一, 难以同时调控CO2活化与C-C耦合这两个关键过程, 限制了C2产物的生成. CuInS2材料因天然具备双金属位点及优异的可见光响应性能而被视为生成C2产物的潜在候选材料, 但依然存在光生载流子复合率高, 产物选择性差等问题. 因此, 采用原子掺杂与缺陷工程相结合的手段, 协同调控活性位点的几何构型和电子结构, 是突破C2H4产物选择性瓶颈的关键.

本文通过一步溶剂热法成功构筑了具有自发形成硫空位(Sv)的Zn掺杂CuInS2 (Zn-CIS)光催化剂, 揭示了Zn掺杂诱导Sv形成并协同构建Cu-Zn双活性位点的作用机制. X-射线衍射和高分辨透射电镜证明Zn2+优先取代In3+位点, 导致显著的晶格收缩. 密度泛函理论计算表明, 这种取代引起了体系电荷不平衡, 从而通过热力学自发的电荷补偿形成了Sv. Sv作为浅施主缺陷, 使费米能级显著上移0.375 eV, 增强了材料的n型半导体特性与整体还原能力, 并提升了光生载流子的分离与传输效率. Bader电荷分析与X-射线吸收近边结构谱共同证实了电子从Sv向邻近Zn位点的转移. 扩展边X-射线吸收精细结构谱则表明, Zn-S键长缩短且配位数约为3, 为Zn掺杂促进Sv形成提供了关键结构证据. 结合原位漫反射傅立叶变换红外光谱和吉布斯自由能计算, 明确了CO2制乙烯的反应路径为*CO2 → *COOH → *CO → *CHO → *COCHO → C2H4. 同时, 理论计算从原子尺度揭示了Zn和Cu双位点协同活化机制. Zn掺杂产生了相邻的Cu-Zn双位点, 将C-C耦合位点间距从3.97 Å缩短至2.60 Å, CO2分子通过Cu-C (1.96 Å)与Zn-O (1.90 Å)键强化学吸附于Cu-Zn双位点, 导致显著弯曲(O-C-O键角122.3°)及C-O键不对称拉长(1.23和1.34 Å)而实现高效活化. 态密度分析进一步从电子层面阐明, Sv引起的电荷重分布使邻近Zn位点由电子受体转为电子给体, 其激活的Zn 3d轨道与CO2成键轨道耦合(4σ/1π), 同时, Cu的3d轨道与CO2的2π*反键轨道产生d-p杂化. 这两种协同作用共同促进了CO2的吸附与活化. 这种“缺陷介导的轨道调控”使速决步的能垒降低了0.41 eV, 促进了高效的*CO → *CHO → *COCHO二聚化, 使C2H4产率相较于CuInS2提高了5.9倍, 达到15.9 μmol g-1 h-1, 且C2H4的电子选择性为77.5%.

综上, 本研究通过缺陷介导的双位点工程, 实现了光催化CO2向乙烯的高效高选择性转化, 且从轨道层面阐明了Zn掺杂与硫空位协同促进CO2活化与C-C偶联的机制, 为太阳能碳资源转化及碳中和目标推进提供助力.

关键词: 光催化CO2还原, Zn掺杂CuInS2, 硫空位, C-C偶联

Abstract:

The photocatalytic conversion of CO2 into high-value fuels represents a promising strategy for achieving carbon neutrality by utilizing solar energy. Overcoming kinetic barriers in multi-electron transfer and C-C coupling is critical for photocatalytic CO2-to-C2H4 conversion. Herein, Zn-doped CuInS2 (Zn-CIS) with spontaneously generated sulfur vacancies (Sv) was designed and constructed for highly selective photocatalytic CO2 reduction. Experimental and density functional theory studies reveal that Zn2+ preferentially substitutes In3+ sites, inducing Sv formation via charge compensation. Sv acts as an electron reservoir, elevating the Fermi level (Ef) by 0.375 eV and prolonging lifetime of photogenerated charge carriers. Moreover, Zn2+ substitution creates adjacent Cu-Zn dual sites with a 2.60 Å spacing, enabling an asymmetric coordination where CO2 bonds via Cu-C and Zn-O interactions. Furthermore, Sv-mediated charge redistribution activates the Zn 3d orbitals, driving their coupling with the CO2 bonding orbitals (4σ/1π), which synergizes with Cu 3d-CO2 2π* antibonding hybridization and promotes the adsorption and activation of CO2 molecules. This dual-site synergy reduces the energy barrier of the rate-determining step by 0.41 eV and drives efficient *CO → *CHO → *COCHO dimerization, resulting in a 15.9 μmol g-1 h-1 C2H4 yield, 5.9-fold enhancement with 77.5% electron selectivity. This work highlights the effectiveness of defect-mediated dual-site engineering, coupled with orbital-level insights, facilitating efficient C2 product formation and provides a new paradigm for solar-driven carbon resource conversion.

Key words: Photocatalytic CO2 reduction, Zn-doped CuInS2, Sulfur vacancies, C-C coupling