Wang Yang, Zhang Wei, Li Dan, Guo Jianping, Yu Yu, Ding Kejian, Duan Wubiao, Li Xiyou, Liu Heyuan, Su Pengkun, Liu Bo, Li Jianfeng
College of Materials Science and Opto-electronic Technology, CAS Center for Excellence in Topological Quantum Computation & Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Yanqi Lake, Huairou District Beijing 101408 P. R. China.
Department of Chemistry, School of Science Beijing Jiaotong University Beijing 100044 P. R. China.
Adv Sci (Weinh). 2021 May 7;8(13):2004456. doi: 10.1002/advs.202004456. eCollection 2021 Jul.
Manipulation of the co-catalyst plays a vital role in charge separation and reactant activation to enhance the activity of metal-organic framework-based photocatalysts. However, clarifying and controlling co-catalyst related charge transfer process and parameters are still challenging. Herein, three parameters are proposed, (the electron transfer rate from MOF to co-catalyst), (the electron transfer distance from MOF to co-catalyst), and (the electron consume rate from co-catalyst to the reactant), related to Pt on UiO-66-NH in a photocatalytic process. These parameters can be controlled by rational manipulation of the co-catalyst via three steps: i) Compositional design by partial substitution of Pt with Pd to form PtPd alloy, ii) location control by encapsulating the PtPd alloy into UiO-66-NH crystals, and iii) facet selection by exposing the encapsulated PtPd alloy (100) facets. As revealed by ultrafast transient absorption spectroscopy and first-principles simulations, the new Schottky junction (PtPd (100)@UiO-66-NH) with higher and exhibits enhanced electron-hole separation and HO activation than the traditional Pt/UiO-66-NH junction, thereby leading to a significant enhancement in the photoactivity.
助催化剂的调控在电荷分离和反应物活化以提高金属有机框架基光催化剂的活性方面起着至关重要的作用。然而，阐明和控制与助催化剂相关的电荷转移过程及参数仍然具有挑战性。在此，提出了三个与光催化过程中UiO-66-NH上的Pt相关的参数，即 （从金属有机框架到助催化剂的电子转移速率）、 （从金属有机框架到助催化剂的电子转移距离）和 （从助催化剂到反应物的电子消耗速率）。这些参数可通过对助催化剂进行合理调控分三步实现：i）通过用Pd部分替代Pt形成PtPd合金进行组成设计；ii）通过将PtPd合金封装到UiO-66-NH晶体中来控制位置；iii）通过暴露封装的PtPd合金（100）晶面进行晶面选择。超快瞬态吸收光谱和第一性原理模拟表明，具有更高 和 的新型肖特基结（PtPd（100）@UiO-66-NH）比传统的Pt/UiO-66-NH结表现出更强的电子-空穴分离和·OH活化能力，从而导致光活性显著增强。
