催化学报 ›› 2024, Vol. 63: 190-201.DOI: 10.1016/S1872-2067(24)60066-5

• 论文 • 上一篇    下一篇

S型CuInS2@CoS2异质结促进电荷转移以实现高效光催化CO2还原

王福林a,1, 李祥伟a,1, 卢康强a, 周漫b,*(), 余长林c,*(), 杨凯a,*()   

  1. a江西理工大学化学化工学院, 江西赣州 341000
    b赣南医科大学药学院, 江西赣州 341000
    c广东石油化工学院化学工程学院, 广东茂名 525000
  • 收稿日期:2024-04-24 接受日期:2024-06-02 出版日期:2024-08-18 发布日期:2024-08-19
  • 通讯作者: *电子信箱: yangkai@jxust.edu.cn (杨凯),baiyuwawa-zhouman@163.com (周漫),yuchanglinjx@163.com (余长林).
  • 作者简介:

    1共同第一作者.

  • 基金资助:
    国家自然科学基金(22366018);国家自然科学基金(5236005);国家自然科学基金(22272034);江西省自然科学基金重点项目(20232ACB203022);江西省自然科学基金重点项目(20224ACB213010);江西双千人才培养计划(jxsq2023201086);江西双千人才培养计划(jxsq2023102141);江西双千人才培养计划(jxsq2023102142);江西双千人才培养计划(jxsq2023102143);江西理工大学清江拔尖人才计划(JXUSTQJBJ2020005);江西省自然科学基金(20224BAB203018);江西省研究生创新专项基金项目(YC2022-S659)

Molten salt construction of core-shell structured S-scheme CuInS2@CoS2 heterojunction to boost charge transfer for efficient photocatalytic CO2 reduction

Fulin Wanga,1, Xiangwei Lia,1, Kangqiang Lua, Man Zhoub,*(), Changlin Yuc,*(), Kai Yanga,*()   

  1. aSchool of Chemistry and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi, China
    bSchool of Pharmacy, Gannan Medical University, Ganzhou 341000, Jiangxi, China
    cSchool of Chemical Engineering, Key Laboratory of Petrochemical Pollution Process and Control, Guangdong Province, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China
  • Received:2024-04-24 Accepted:2024-06-02 Online:2024-08-18 Published:2024-08-19
  • Contact: *E-mail: yangkai@jxust.edu.cn (K. Yang), baiyuwawa-zhouman@163.com (M. Zhou), yuchanglinjx@163.com (C. Yu).
  • About author:

    1Contributed equally to this work.

  • Supported by:
    National Natural Science Foundation of China(22366018);National Natural Science Foundation of China(5236005);National Natural Science Foundation of China(22272034);Key Projects of Jiangxi Provincial Natural Science Foundation(20232ACB203022);Key Projects of Jiangxi Provincial Natural Science Foundation(20224ACB213010);Jiangxi Province “Double Thousand” Talent Training Plan(jxsq2023201086);Jiangxi Province “Double Thousand” Talent Training Plan(jxsq2023102141);Jiangxi Province “Double Thousand” Talent Training Plan(jxsq2023102142);Jiangxi Province “Double Thousand” Talent Training Plan(jxsq2023102143);Program of Qingjiang Excellent Young Talents, JXUST(JXUSTQJBJ2020005);Jiangxi Provincial Natural Science Foundation(20224BAB203018);Jiangxi Province Graduate Innovation Special Fund Project(YC2022-S659)

摘要:

利用太阳能将CO2和H2O转化为CO, CH4和CH3OH等碳基燃料是一种清洁和可持续技术. 然而, 较弱的氧化还原能力和严重的电荷重组阻碍了CO2光还原技术的实际应用. 为应对该挑战, 多组分体系的构建是提高光催化性能的最有效途径之一. 近年来, S型异质结受到研究人员的广泛关注, 为复合体系的光催化剂提供了新的发展方向. S型异质结通常由具有更负的导带(CB)电位的还原型半导体(RP)和具有更正的价带(VB)电位的氧化型半导体(OP)组成. 在S型异质结中, 强内建电场的存在驱动电子和空穴分别在RP的CB和OP的VB上积累. 这种积累克服了II型异质结氧化还原能力弱的缺点, 并且有效改善了单个半导体电子-空穴对快速复合和光吸收范围有限的问题. 因此, 构建匹配良好的S型异质结构和建立强大的内建电场是提高CO2光转换效率的重要策略.

本文通过两步熔盐法设计合成了核壳结构的CuInS2@CoS2(CIS-CS) S型异质结光催化剂. 熔盐法不仅有利于高结晶CuInS2的形成, 使CuInS2与CoS2充分接触, 实现电子高效转移, 还可以为光催化CO2还原提供更多的比表面积和活性位点. 合成的CuInS2@CoS2异质结构表现出较好的CO2光还原性能, 光照2 h下CO的产率为239 μmol g‒1 h‒1, 分别是纯CuInS2和CoS2的21.7倍和26.5倍. X射线粉末衍射、扫描电镜、透射电镜和氮气等温吸附脱附曲线等表征测试证明了CuInS2@CoS2复合材料的结构特征. 采用光电化学测试、光致发光光谱和时间分辨光致发光光谱研究了催化剂的载流子分离和重组行为. 原位光照X射线光电子能谱和功函数计算证明了异质结符合S型电荷转移机制, 开尔文探针力显微镜证明了异质结具有更大的内建电场强度. 在黑暗条件下, 由于CoS2和CuInS2在界面上的费米能级存在差异, 当两种材料复合时, 电子会自发地从CoS2迁移到CuInS2, 直到费米能级达到平衡, 从而在复合材料的界面处产生了强内建电场. 在光照下, 电子由CuInS2转移到CoS2, 内建电场的存在诱导了电荷的定向迁移使得光生载流子能够有效分离, 从而提高了CuInS2@CoS2异质结的光催化活性. 此外, 原位光照傅里叶变换红外光谱研究了光催化CO2还原反应的中间体, 并进一步通过密度泛函理论计算证实了CuInS2@CoS2异质结降低了*COOH和*CO的形成能.

综上, 通过两步熔融盐法成功合成了CuInS2@CoS2(CIS-CS) S型异质结光催化剂. S型异质结构的形成有效增强了材料的内建电场, 并促进光生载流子的高效分离和转移, 从而获得了优异的光催化CO2还原为CO的性能. 本文为通过熔盐方法设计合成S型异质结光催化剂提供了参考.

关键词: S型异质结, 熔融盐, CuInS2, CoS2, CO2光还原

Abstract:

Weak redox ability and severe charge recombination pose significant obstacles to the advancement of CO2 photoreduction. To tackle this challenge and enhance the CO2 photoconversion efficiency, fabricating well-matched S-scheme heterostructure and establishing a robust built-in electric field emerge as pivotal strategies. In pursuit of this goal, a core-shell structured CuInS2@CoS2 S-scheme heterojunction was meticulously engineered through a two-step molten salt method. This approach over the CuInS2-based composites produced an internal electric field owing to the disparity between the Fermi levels of CoS2 and CuInS2 at their interface. Consequently, the electric field facilitated the directed migration of charges and the proficient separation of photoinduced carriers. The resulting CuInS2@CoS2 heterostructure exhibited remarkable CO2 photoreduction performance, which was 21.7 and 26.5 times that of pure CuInS2 and CoS2, respectively. The S-scheme heterojunction photogenerated charge transfer mechanism was validated through a series of rigorous analyses, including in situ irradiation X-ray photoelectron spectroscopy, work function calculations, and differential charge density examinations. Furthermore, in situ infrared spectroscopy and density functional theory calculations corroborated the fact that the CuInS2@CoS2 heterojunction substantially lowered the formation energy of *COOH and *CO. This study demonstrates the application potential of S-scheme heterojunctions fabricated via the molten salt method in the realm of addressing carbon-related environmental issues.

Key words: S-scheme heterojunction, Molten salt, CuInS2, CoS2, CO2 photoreduction