Department of Chemistry, University of Chicago, 929 E. 57th Street, Chicago, IL, 60637, USA.
Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P.R. China.
Angew Chem Int Ed Engl. 2016 May 23;55(22):6411-6. doi: 10.1002/anie.201600431. Epub 2016 Apr 20.
Metal-organic frameworks (MOFs) provide a tunable platform for hierarchically integrating multiple components to effect synergistic functions that cannot be achieved in solution. Here we report the encapsulation of a Ni-containing polyoxometalate (POM) Ni4 (H2 O)2 (PW9 O34 )2 (Ni4 P2 ) into two highly stable and porous phosphorescent MOFs. The proximity of Ni4 P2 to multiple photosensitizers in Ni4 P2 @MOF allows for facile multi-electron transfer to enable efficient visible-light-driven hydrogen evolution reaction (HER) with turnover numbers as high as 1476. Photophysical and electrochemical studies established the oxidative quenching of the excited photosensitizer by Ni4 P2 as the initiating step of HER and explained the drastic catalytic activity difference of the two POM@MOFs. Our work shows that POM@MOF assemblies not only provide a tunable platform for designing highly effective photocatalytic HER catalysts but also facilitate detailed mechanistic understanding of HER processes.
金属-有机骨架（MOFs）为分层集成多种组分提供了一个可调谐的平台，从而产生协同作用，这在溶液中是无法实现的。在这里，我们报告了将含镍的多金属氧酸盐（POM）[Ni4（H2O）2（PW9O34）2]（10-）（Ni4P2）封装到两个高度稳定和多孔的磷光 MOF 中。Ni4P2 与 Ni4P2@MOF 中多个光敏剂的接近性允许进行简便的多电子转移，从而能够在可见光驱动下高效地进行析氢反应（HER），周转数高达 1476。光物理和电化学研究确立了 Ni4P2 对激发态光敏剂的氧化猝灭是 HER 的起始步骤，并解释了两种 POM@MOF 的催化活性差异。我们的工作表明，POM@MOF 组装不仅为设计高效的光催化 HER 催化剂提供了一个可调谐的平台，而且还促进了对 HER 过程的详细机理理解。
