Wang He, Zhang Xiyuan, Zhang Wei, Zhou Meng, Jiang Hai-Long
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Angew Chem Int Ed Engl. 2024 Apr 22;63(17):e202401443. doi: 10.1002/anie.202401443. Epub 2024 Mar 12.
Atomically precise metal nanoclusters (NCs) with unique optical properties and abundant catalytic sites are promising in photocatalysis. However, their light-induced instability and the difficulty of utilizing the photogenerated carriers for photocatalysis pose significant challenges. Here, MAg (M=Ag, Pd, Pt, and Au) NCs doped with diverse single heteroatoms have been encapsulated in a metal-organic framework (MOF), UiO-66-NH, affording MAg@UiO-66-NH. Strikingly, compared with Ag@UiO-66-NH, the MAg@UiO-66-NH doped with heteroatom exhibits much enhanced activity in photocatalytic hydrogen production, among which AuAg@UiO-66-NH presents the best activity up to 3.6 mmol g h, far superior to all other counterparts. Moreover, they display excellent photocatalytic recyclability and stability. X-ray photoelectron spectroscopy and ultrafast transient absorption spectroscopy demonstrate that MAg NCs encapsulated into the MOF create a favorable charge transfer pathway, similar to a Z-scheme heterojunction, when exposed to visible light. This promotes charge separation, along with optimized Ag electronic state, which are responsible for the superior activity in photocatalytic hydrogen production.
具有独特光学性质和丰富催化位点的原子精确金属纳米团簇（NCs）在光催化领域颇具前景。然而，它们光致不稳定性以及利用光生载流子进行光催化的困难构成了重大挑战。在此，掺杂有不同单一杂原子的MAg（M = Ag、Pd、Pt和Au）NCs被封装在金属有机框架（MOF）UiO - 66 - NH中，得到MAg@UiO - 66 - NH。令人惊讶的是，与Ag@UiO - 66 - NH相比，掺杂杂原子的MAg@UiO - 66 - NH在光催化产氢方面表现出显著增强的活性，其中AuAg@UiO - 66 - NH的活性最佳，高达3.6 mmol g h，远优于所有其他同类材料。此外，它们还表现出优异的光催化可回收性和稳定性。X射线光电子能谱和超快瞬态吸收光谱表明，封装在MOF中的MAg NCs在可见光照射下形成了类似于Z型异质结的有利电荷转移途径。这促进了电荷分离，同时优化了Ag的电子态，这是光催化产氢具有优异活性的原因。
