由质子化D-A型聚合物和MoS_(2)构建S型异质结实现高效光催化析氢  

Construction of S‐scheme heterojunction from protonated D‐A typed polymer and MoS_(2) for efficient photocatalytic H_(2) production

作　　者：潘劲康 张艾彩珺 张莉华 董鹏玉[1] Jinkang Pan;Aicaijun Zhang;Lihua Zhang;Pengyu Dong(Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province,Yancheng Institute of Technology,Yancheng 224051,Jiangsu,China;School of Chemistry and Chemical Engineering,Yancheng Institute of Technology,Yancheng 224051,Jiangsu,China;School of Mechanical Engineering,Yancheng Institute of Technology,Yancheng 224051,Jiangsu,China)

机构地区：[1]盐城工学院,江苏省新型环保重点实验室,江苏盐城224051 [2]盐城工学院化学化工学院,江苏盐城224051 [3]盐城工学院机械工程学院,江苏盐城224051

出　　处：《Chinese Journal of Catalysis》2024年第3期180-193,共14页催化学报（英文）

基　　金：国家自然科学基金(21403184);江苏省“青蓝工程”项目;江苏省高等学校基础科学(自然科学)研究重大项目(22KJA430008);盐城工学院分析测试中心支持.

摘　　要：化石能源的过度消耗及其所引发的环境污染已经成为制约人类社会可持续发展的关键因素,因此开发绿色、可再生的能源已成为全球的迫切需求.氢能作为一种新型能源,具有能量密度高、清洁以及可持续等优点,备受研究者的关注.光催化分解水制氢技术能够将太阳能转化为可储存的清洁能源,被视为未来解决能源和环境问题的可行性方案.在过去几十年里,众多科学家致力于研发各种高效的析氢光催化剂,以推进光催化分解水制氢技术的实际应用.其中,S型异质结光催化剂因其快速的光生电荷转移效率和出色的氧化还原能力,被认为是提高光催化析氢性能的有效途径之一.本文以质子化、具有供体-受体(D-A)构型的PyDTDO-3共轭聚合物和二维层状MoS_(2)为原料,构建了一种S型异质结(PPMS),并将其用于光催化分解水制氢.红外光谱结果表明,质子化处理导致PyDTDO-3表面吸附了大量H^(+),使其Zeta电势降低,表面负电荷减少,更有利于MoS_(2)的吸附,进而形成具有紧密接触界面的PPMS S型异质结.在可见光照射下,PPMS-0.5%(即MoS_(2)占PyDTDO-3的质量百分数为0.5%)S型异质结的性能最佳,其光催化析氢效率达到75.4 mmol g^(–1)h^(–1),是纯PyDTDO-3的4.6倍.此外,在550 nm光激发下,PPMS-0.5%异质结的光催化析氢表观量子效率最高达到19.6%.光电流响应和电化学阻抗谱结果表明,PPMS异质结展现出了显著提升的光生电荷分离效率.通过密度泛函理论计算发现,PyDTDO-3和MoS_(2)具有不同的功函数,这导致费米能级间隙的产生,从而形成了内建电场.该内建电场有助于MoS_(2)上的电子自发转移到PyDTDO-3上,从而在PyDTDO-3与MoS_(2)的界面上产生了明显的差分电荷密度分布:PyDTDO-3表面带有负电荷,MoS_(2)表面则带有正电荷.在可见光激发下,得益于PyDTDO-3独特的D-A型结构,光生电子可以快速从供体(芘供体)的最高占据分子轨道传递到�This study involves a heterojunction(denoted as PPMS)with an intimate heterointerface and S-scheme architecture,which consisted of a conjugated polymer of protonated PyDTDO-3 featuring a donor-acceptor(D-A)configuration and a 2D-layered MoS_(2).The optimal PPMS-0.5%heterojunction exhibits a remarkable efficiency of 75.4 mmol g^(‒1)h^(–1)in generating H_(2) when subjected to visible light illumination,representing an approximately 4.6 times enhancement compared to pure PyDTDO-3.To elucidate the photocatalytic mechanism,a range of characterization methods were utilized and calculations using density functional theory were carried out.The disparity in the work function between PyDTDO-3 and MoS_(2)results in the creation of a Fermi-level gap.Consequently,the establishment of a built-in electric field facilitates the occurrence of the electrons in MoS_(2)spontaneously transferring to PyDTDO-3 at the interface.The consumption of hole on the valence band of MoS_(2) is accelerated by the electron transfer from the lowest unoccupied molecular orbital(LUMO)of PyDTDO-3,according to a kinetic study using femtosecond transient absorption spectra(fs-TAS).Moreover,the S-scheme PPMS exhibits a lower Gibbs free energy(ΔGH*,0.77 eV)in comparison to the individual component,indicating it facilitates the formation of the transitional state(H*)and the effective desorption of molecular hydrogen on PPMS.Both the promoting directed charge migration and the increasing active sites contribute to the boosted photocatalytic H2 evolution.

关 键 词：S型异质结 质子化D-A型聚合物 MoS_(2) 光催化析氢 密度泛函理论计算 

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