催化学报 ›› 2025, Vol. 73: 242-251.DOI: 10.1016/S1872-2067(25)64687-0

• 论文 • 上一篇    下一篇

具有氧空位的多孔超薄NiO纳米片用于光催化CO2还原

李睿a, 冯鹏飞a, 李柏男a, 朱佳玉a, 张雅丽b, 张泽a, 张江威b(), 丁勇a,c()   

  1. a兰州大学化学化工学院, 天然产物化学全国重点实验室, 甘肃省先进催化重点实验室, 甘肃兰州 730000
    b内蒙古大学能源材料化学研究院, 经济管理学院, 内蒙古呼和浩特 010021
    c中国科学院兰州化学物理研究所, 低碳催化与二氧化碳利用全国重点实验室(筹), 羰基合成与选择氧化国家重点实验室, 甘肃兰州 730000
  • 收稿日期:2025-03-03 接受日期:2025-04-15 出版日期:2025-06-18 发布日期:2025-06-12
  • 通讯作者: *电子信箱: zjw11@tsinghua.org.cn/jwz@imu.edu.cn (张江威), dingyong1@lzu.edu.cn (丁勇).
  • 基金资助:
    国家自然科学基金(22075119);国家自然科学基金(22472071);国家自然科学基金(U22A20107);甘肃省自然科学基金(21JR7RA440);内蒙古自治区青年科技英才(NJYT23030);碳中和研究项目(STZX202218);内蒙古自治区自然科学基金(2023MS02002);广东省能量转换材料与技术重点实验室(MATEC2024KF011)

Photocatalytic reduction of CO2 over porous ultrathin NiO nanosheets with oxygen vacancies

Rui Lia, Pengfei Fenga, Bonan Lia, Jiayu Zhua, Yali Zhangb, Ze Zhanga, Jiangwei Zhangb(), Yong Dinga,c()   

  1. aState Key Laboratory of Applied Organic Chemistry, Key Laboratory of Advanced Catalysis of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, China
    bCollege of Energy Material and Chemistry, School of Economics and Management Inner Mongolia University, Hohhot 010021, Inner Mongolia, China
    cState Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization; State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
  • Received:2025-03-03 Accepted:2025-04-15 Online:2025-06-18 Published:2025-06-12
  • Contact: *E-mail: zjw11@tsinghua.org.cn/jwz@imu.edu.cn (J. Zhang), dingyong1@lzu.edu.cn (Y. Ding).
  • Supported by:
    National Natural Science Foundation of China(22075119);National Natural Science Foundation of China(22472071);National Natural Science Foundation of China(U22A20107);Natural Science Foundation of Gansu Province, China(21JR7RA440);Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT23030);Carbon neutralization research project(STZX202218);Inner Mongolia Autonomous Region Natural Science Foundation(2023MS02002);Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(MATEC2024KF011)

摘要:

近年来, 光催化CO2还原反应被认为是缓解温室效应的关键途径之一. 然而, 大气中CO2浓度较低(约416 ppm), 亟需开发兼具高效CO2富集能力和优异电荷分离性能的催化剂. 过渡金属氧化物因其稳定性高、成本低等优势被广泛研究, 但其光生载流子分离效率低、活性位点不足等问题限制了其实际应用. 本文通过形貌工程与氧空位调控, 设计并合成了一系列超薄多孔NiO纳米片, 旨在解决传统金属氧化物催化剂吸附能力弱、电荷分离效率低等瓶颈. 该研究不仅为低浓度CO2的高效还原提供了新策略, 还揭示了O2对CO2还原产物选择性的调控作用, 对推动光催化CO2转化技术实际应用具有重要意义.

本文通过美拉德反应制备了具有丰富氧空位的超薄多孔NiO纳米片. 根据原料硝酸镍用量和煅烧温度的不同,得到9种不同的NiO, 分别记为NiO-1至NiO-9. 通过调控前驱体用量与煅烧温度, 优化了纳米片的厚度(2-3 nm)、比表面积(NiO-1为最高)及氧空位含量. 结合X射线衍射谱、X射线光电子能谱、电子顺磁共振谱和扩展X-射线吸收精细结构谱等表征手段和密度泛函理论计算, 证实氧空位的引入导致NiO晶格畸变, 形成内建电场, 显著提升了光生载流子的分离效率与CO2吸附能力. 在纯CO2气氛下, NiO-1表现出最优的光催化性能: CO产率达16.8 μmol/h, 选择性达96%. 理论计算表明, 氧空位通过改变催化剂表面的偶极矩, 促进了CO2分子的吸附与活化. 此外, 在空气气氛(含21% O2)中, 反应产物由单一CO转变为CO与CH4的混合物. 通过原位红外光谱与对照实验, 发现O2的存在促使光敏剂作为还原位点, 促进水分解产生活性质子, 进而改变反应路径. 机理研究表明, NiO-1的氧空位通过以下途径提升性能: (1) 增强CO2吸附能力; (2) 诱导晶格畸变, 形成内部电场以加速电荷分离. 然而, 循环实验中氧空位的逐渐流失导致活性下降, 提示未来需进一步优化催化剂的稳定性.

综上所述, 具有氧空位的超薄多孔NiO纳米片在[Ru(bpy)3]Cl2体系中展现出优异的CO选择性和产率, 并发现O2可诱导产物从单一CO向CO/CH4混合体系转变. 尽管O2对光催化CO2还原反应的影响机制仍需深入探索, 但通过一系列表征与理论计算揭示了氧空位通过改变偶极矩优化电荷分离与CO2吸附能力的关键作用, 为低浓度CO2还原催化剂的理性设计提供了新范式.

关键词: 光催化CO2还原, [Ru(bpy)3]Cl2, 氧化镍, 氧空位, 低浓度CO2

Abstract:

In recent years, photocatalytic CO2 reduction reaction has been recognized as a crucial approach to solve the greenhouse effect. However, the low concentration of CO2 in the atmosphere necessitates a catalyst with excellent CO2 enrichment capability. Herein, we designed and synthesized a series of NiO nanosheets featuring oxygen vacancies. Under the condition of pure CO2 and photosensitizer [Ru(bpy)3]Cl2, the yield of CO reaches 16.8 μmol/h with a selectivity of 96%. Through characterization and theoretical calculations, we demonstrate that the presence of oxygen vacancies not only enhances the adsorption capacity of catalysts but also induces lattice distortion in NiO, leading to an increased dipole moment and formation of an internal electric field that facilitates photogenerated carrier separation. Furthermore, we conducted CO2 reduction reactions under atmospheric condition and surprisingly observed a changing of selectivity from CO to CO and CH4. A series of control experiments showed that [Ru(bpy)3]Cl2 acts as a reduction reaction site due to the presence of O2 in the atmosphere. Simultaneously, oxygen promotes water splitting, which results in abundant proton generation and subsequent changes in carbon products.

Key words: Photocatalytic CO2 reduction, [Ru(bpy)3]Cl2, NiO, Oxygen vacancy, Low concentration CO2