A thioether-functionalized pyrene-based covalent organic framework anchoring ultrafine Au nanoparticles for efficient photocatalytic hydrogen generation  

一种锚定精细金纳米颗粒的硫醚功能化芘基共价有机框架用于高效光催化制氢

作　　者：Zhiming Zhou Chuanbiao Bie Peize Li Bien Tan Yan Shen 周志明;别传彪;李沛泽;谭必恩;申燕(华中科技大学武汉光电国家实验室,湖北武汉430074;华中科技大学化学与化工学院,能源转化与存储材料化学教育部重点实验室,湖北武汉430074;中国地质大学材料与化学学院,太阳燃料实验室,湖北武汉430074)

机构地区：[1]Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,Hubei,China [2]Key Laboratory of Material Chemistry for Energy Conversion and Storage,Ministry of Education,School of Chemistry and Chemical Engineering,Huazhong University of Science and Technology,Wuhan 430074,Hubei,China [3]Laboratory of Solar Fuel,Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan 430074,Hubei,China

出　　处：《Chinese Journal of Catalysis》2022年第10期2699-2707,共9页催化学报（英文）

基　　金：国家自然科学基金重大国际(地区)联合研究项目NSFC-SNSF(51661135023);国家自然科学基金(21673091);中央高校基本科研业务费专项资金(HUST:2016YXMS031);电分析化学国家重点实验室开放基金(SKLEAC201607).

摘　　要：Covalent organic frameworks(COFs)have lately emerged as a blooming class of potential materials for photocatalytic water splitting because of their high crystallinity,huge surface areas,and structural versatility.However,the photocatalytic performance for most pure COFs face some limitations factors,such as the significant recombination of photogenerated carriers and slow charge transfer.Herein,a novel thioether-functionalized pyrene-based COF(S_(4)-COF)was effectively produced and chosen as a support for the immobilization of ultrafine gold nanoparticles(Au NPs).S_(4)-COF photocatalyst with Au as cocatalyst demonstrates remarkable photocatalytic activity with a H_(2) generation rate of 1377μmol g^(−1) h^(−1) under visible light(>420 nm),which is ca.4.5-fold increase comparing to that of pure S_(4)-COF(302μmol g^(−1) h^(−1)).Au NPs anchored on S_(4)-COF possess an ultrafine size distribution ranging from 1.75 to 6.25 nm with an average size centered at 3.8 nm,which benefits from the coordination interaction between thioether groups and Au.Meanwhile,the produced Au@S_(4)-COF can generate a stable photocatalytic H_(2) generation during the four recycles and preserve its crystallinity structure after the stability testing.The Au NPs anchored on the S_(4)-COF photocatalyst can greatly accelerate the separation of photogenerated carriers and increase charge transfer because of the combined function of Au NPs and thioether groups.Such a method can not only prevent the aggregation of Au NPs onto thioether-containing COFs to achieve long-term photostability but also allow uniform dispersion for an ordered structure of photocatalysts.This work provides a rational strategy for designing and preparing COF-based photocatalysts for solar-driven H_(2) production.氢能(H2)因其高能量密度而被认为是一种有望解决全球能源危机,极具应用前景的可再生能源.光催化分解水制氢技术在能源研究领域受到广泛的关注,国内外研究者在探索和开发高效光驱动制氢的光催化剂方面做出了巨大努力.近年来,共价有机框架(COFs)因结晶性高、比表面积大和结构可设计性强等特性,而成为最具潜力的光催化有机多孔材料之一,并广泛应用于光催化分解水制氢.此外,由强共价键构筑而成的COFs,尤其是酰腙链接的COFs,通常展现出较好的结构稳定性,这有利于催化剂在光催化水分解过程中保持稳定的结构.然而,大多数纯COFs由于表面电荷传输缓慢以及光生载流子容易复合,使其光催化分解水性能不理想.如何加快电荷传输,促进光生载流子分离,进而提高COFs的光催化效率成为关键问题.本文制备了一种新型硫醚功能化的芘基COF(S_(4)-COF),通过原位光沉积技术将精细金纳米颗粒(Au NPs)负载于S_(4)-COF上,制得Au@S_(4)-COF复合光催化剂,并用于光催化分解水制氢.通过傅里叶变换红外光谱、核磁共振波谱、X射线多晶衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱等表征深入研究了S_(4)-COF的链接方式、晶型结构和形貌,证明了精细Au NPs均匀负载在S_(4)-COF表面.利用紫外-可见吸收光谱研究了S_(4)-COF和复合光催化剂Au@S_(4)-COF的光学性质,结果表明,与纯S_(4)-COF相比,Au@S_(4)-COF在可见光范围内光吸收能力增强.在可见光(λ>420 nm)照射下,以三乙醇胺作为电子牺牲剂进行光催化析氢实验.结果发现,在没有任何助催化剂的情况下,纯S_(4)-COF光催化制氢产率为302μmol g^(−1) h^(−1);而Au@S_(4)-COF复合光催化剂的光催化析氢活性明显提升,H2析出速率为1377μmol g^(−1) h^(−1),约为纯S_(4)-COF的4.5倍.同时,Au@S_(4)-COF在循环实验中表现出稳定的光催化析氢性能,并在反应后完整�

关 键 词：Photocatalysis Covalent organic framework Thioether functionalization Gold nanoparticle Coordination interaction Photogenerated carrier separation 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]