催化学报 ›› 2024, Vol. 56: 88-103.DOI: 10.1016/S1872-2067(23)64563-2

• 论文 • 上一篇    下一篇

CuMn2O4/石墨炔S型异质结上锚定氧化助催化剂促进曙红敏化光催化析氢

杨成a, 李鑫b,*(), 李梅a, 梁桂杰c, 靳治良a,*()   

  1. a北方民族大学化学与化学工程学院, 宁夏太阳能化学转化技术重点实验室, 国家民委化学工程与技术重点实验室, 宁夏银川750021
    b华南农业大学能源植物资源与利用农业农村部重点实验室, 生物质工程研究所, 广东广州510642
    c湖北文理学院低维光电材料与器件湖北省重点实验室, 湖北襄阳441053
  • 收稿日期:2023-10-15 接受日期:2023-11-13 出版日期:2024-01-18 发布日期:2024-01-10
  • 通讯作者: *电子信箱: xinli@scau.edu.cn (李鑫), zl-jin@nun.edu.cn (靳治良).
  • 基金资助:
    宁夏回族自治区自然科学基金(2023AAC02046)

Anchoring oxidation co-catalyst over CuMn2O4/graphdiyne S-scheme heterojunction to promote eosin-sensitized photocatalytic hydrogen evolution

Cheng Yanga, Xin Lib,*(), Mei Lia, Guijie Liangc, Zhiliang Jina,*()   

  1. aNingxia Key Laboratory of Solar Chemical Conversion Technology, Key Laboratory for Chemical Engineering and Technology, State Ethnic Affairs Commission, School of Chemistry and Chemical Engineering, North Minzu University, Yinchuan 750021, Ningxia, China
    bInstitute of Biomass Engineering, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, Guangdong, China
    CHubei Key Lab Low Dimens Optoelect Mat & Devices, Hubei University of Arts and Science, Xiangyang 441053, Hubei, China
  • Received:2023-10-15 Accepted:2023-11-13 Online:2024-01-18 Published:2024-01-10
  • Contact: *E-mail: xinli@scau.edu.cn (X. Li), zl-jin@nun.edu.cn (Z. Jin).
  • Supported by:
    Natural Science Foundation of the Ningxia Hui Autonomous Region(2023AAC02046)

摘要:

半导体光催化剂有效的电荷分离及利用是光催化制氢的关键. 单一半导体催化剂由于光生电子-空穴对的快速复合导致低的光催化活性, 构建异质结是提高光生电荷分离以及电子转移效率的有效方法. 此外, 助催化剂的引入同样能够促进光催化剂表面电子和空穴的分离, 并且其协同效应可促使更多载流子流向相应的助催化剂位点而增强光催化性能. 因此, 同时构建异质结及合适的氧化位点成为解决光生电子-空穴对有效分离及利用的重要研究方向.

本文报道了一种同时构建S型异质结和氧化位点促进CuMn2O4光生电子-空穴对有效分离及利用的可行性策略. 虽然在制备CuMn2O4的过程中通过调控制备温度能够自身诱导生成具有氧化能力的Mn2O3来作为氧化位点, 但是只存在氧化位点时不能很好地克服光生电子-空穴对的重组现象而导致光催化活性较低. 基于此, 本文巧妙地利用CuMn2O4自身诱导生成氧化位点的特性并引入石墨炔还原端而构建S型异质结, 在氧化位点及S型异质结同时存在的情况下增强光生电子的有效转移. 此外, 在自身诱导生成氧化位点和S型异质结的协同作用下, 促进了复合光催化剂中的光生电子和光生空穴精确定向迁移到相应的还原位点和氧化位点. 傅里叶变换红外光谱和拉曼光谱证实成功制备了石墨炔. X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和高分辨透射电子显微镜(TEM)等结果表明, 成功制备了600-CuMn2O4/GDY-40%(6-CG-40%)样品(600 °C焙烧, 石墨炔质量百分含量为40%). 经过组分优化的复合光催化剂6-CG-40%的催化性能达到1586.54 μmol g‒1 h‒1, 是CuMn2O4 (106.73 μmol g‒1 h‒1) 和石墨炔(70.57 μmol g‒1 h‒1)产氢活性的13.86倍和21.48倍高. 利用UV-vis光谱、电化学性能和接触角测试等分析6-CG-40%复合光催化剂产氢性能提升的原因, 并通过密度泛函理论计算和相关实验表征验证Mn2O3作为氧化助催化剂的合理性. 结果表明, 原位诱导生成的Mn2O3氧化助催化剂和引入石墨炔构建的S型异质结有效抑制了光生电子-空穴对的复合, 从而优化了光生载流子转移效率, 最终增强了曙红敏化6-CG-40%光催化析氢性能.

综上所述, 在控制诱导因子原位生成Mn2O3氧化助催化剂的基础上引入石墨炔还原端构建了S型异质结, 在助催化剂与异质结两者的协同作用下极大程度地改善了光生电子-空穴对的严重复合现象, 这项工作为解决光催化制氢领域中制约光催化剂制氢能力的关键问题提供了可行性思路.

关键词: 石墨炔, 氧化助催化剂, 电荷分离, S型异质结, 光催化制氢

Abstract:

It is widely acknowledged that efficient charge separation and utilization of photocatalysts are key factors in determing the photocatalytic hydrogen production. Construction of heterojunction has been considered as a promising way to efficiently solve the spatial separation of photogenerated charges. In addition, the introduction of proper cocatalysts can realize the separation of electrons and holes of the photocatalyst and enhance the photocatalytic performance by promoting more carriers to flow to the corresponding active sites. Herein, the S-scheme heterojunction was constructed by introducing graphdiyne into CuMn2O4 for photocatalytic hydrogen evolution. Graphdiyne as a reduction semiconductor and in situ produced Mn2O3 from CuMn2O4 as an oxidation cocatalyst to promote the precisely migration of photogenerated electrons and holes to the corresponding reduction and oxidation sites of photocatalyst. Notably, the photocatalytic performance of the 600-CuMn2O4/GDY-40%(6-CG-40%)could reach 1586.54 μmol g-1 h-1, which is 13.86 and 21.48 times higher than those of CuMn2O4 (106.73 μmol g-1 h-1) and graphdiyne (70.57 μmol g-1 h-1), respectively. Theoretical calculations and experiments results show that both in-situ induced growth of Mn2O3 oxidation co-catalyst and the introduction of graphdiyne to construct S-scheme heterojunction efficiently suppress the severe recombination of photogenerated electron-hole pairs, thus optimizing the photogenerated carrier transfer efficiency, and ultimately leading to the enhanced eosin Y-sensitized photocatalytic hydrogen evolution activity. This work provides a promising method for the construction of oxidation cocatalyst engineered S-scheme heterojunction for solar water splitting.

Key words: Graphdiyne, Oxidation co-catalyst, Charge separation, S-scheme heterojunction, Photocatalytic hydrogen production