双面(Janus)硫化钼基异质结界面调控及光生电荷输运的研究

Non-Pt hydrogen evolution catalysts (HECs) has not been studied for a long time in photocatalytic H2 generation under solar light irradiation, because they suffer from insufficient active site, high energy barrier at heterointerface and low charge transfer efficiency in HEC/photocatalyst hybrids. Since the photocatalytic H2 evolution performance over non-Pt HECs is lower than that over Pt based photocatalyst, the project will devote to develop highly active non-Pt HECs/photocatalyst materials for solar to hydrogen conversion by taking two-dimensional (2D) MoS2 HEC as example, following which a 2D Janus MoS2/ZnxCd1-xS heterojunction is proposed to achieve highly efficient photocatalytic H2 evolution through controlling of charge transportation at their heterointerface. The 2D Janus MoS2/ZnxCd1-xS heterojunction will be synthesized by liquid phase induced self-assembly and in-situ growth, respectively, during which the influences of defect, phase and size of MoS2 on hydrogen evolution reaction activity and the influences of Zn/Cd ratio of ZnxCd1-xS on interfacial charge flow will be investigated, respectively. Simultaneously, we will investigate the Fermi level, the bandgap energy level between MoS2 and ZnxCd1-xS, as well as the photo-induced charge carrier migration process at heterojunction and resulted electron lifetime. Through these results, we will establish a series of relationships in term of structure-performance, interface-charge flow and interface-H2 evolution, aiming to disclose the synergistic effect of 2D Janus MoS2/ZnxCd1-xS heterojunction for photocatalytic H2 generation. The research results can provide a new technology for preparation of 2D HEC/photocatalyst hybrids, and also provide new materials for highly efficient photocatalytic hydrogen production.

基于类石墨烯二维析氢催化剂在电解水制氢上展现出取代铂系贵金属的巨大潜力，实现二维析氢催化剂的光水解制氢是必然发展趋势和最终研究目标。由于其较高能量壁垒导致电荷传输受限，在光催化制氢过程中，二维析氢催化剂的催化活性及活性点位利用率仍有待提高。本研究拟通过调控二维析氢催化剂异质结界面的电荷输运，来实现其高效的太阳能制氢。以二维MoS2为研究对象，通过液相自组和原位生长两种合成方法构筑二维双面(Janus)MoS2/ZnxCd1-xS异质结，并调控异质结界面特性来实现光生载流子在界面的低损传输。考察ZnxCd1-xS中Zn/Cd的比例对界面电荷传输影响，优化MoS2与ZnxCd1-xS的协同作用机制；调查光生载流子在界面的迁移过程及电子寿命；建立其结构、界面与可见光催化水解制氢间的关系，揭示其协同催化制氢机制。研究成果可为二维纳米异质催化材料制备提供新技术，亦为发展高效光催化水解制氢提供新材料。

本项目研究了具有不同二维异质结界面特性的光催化材料的合成以及其与产氢活性的内在关联，针对光生载流子的界面传输调控作了重点研究，同时我们也进行了一部分二维材料基光电催化光阳极材料的开发，期望能将上述材料与光电化学水分解器件进行有效结合，实现更高性能光解水效率。主要工作总结如下：（1）实现了二维MoS2、WS2的晶相控制，合成出了高催化活性的1T相析氢催化剂；（2）研究了CdS/MoS2异质结光对催化剂的光生空穴向不同电解液的传递效率, 实现了二维析氢催化剂在碱性电解液里的高效光催化制氢；（3）实现了二维黑磷纳米材料在BiVO4基光阳极的合成，提高了光阳极/电解液界面的电荷传递；（4） 实现了光阳极/电解液固液界面电荷传输、传递以及反应动力学的调控。多篇研究论文发表在多种国际刊物上，如： J. Am. Chem. Soc.、Nat. Commun.、ACS. Energy Lett.、Adv. Funct. Mater.、Nano Energy、ACS Catal. Small (2)、J. Mater. Chem. A (2)、ACS Appl. Mater. Interf.、ChemsusChem.、SolarRRL，发表SCI 收录论文13篇，发表论文中有ESI高被引论文1篇；申请专利3项，授权一项。项目执行期间毕业了2位硕士研究生，在读硕士生5人，获得江苏省特聘教授1人。