Hierarchically porous S-scheme CdS/UiO-66 photocatalyst for efficient 4-nitroaniline reduction

Unveiling the pore-size performance of metal organic frameworks (MOFs) is imperative for controllable design of sophisticated catalysts. Herein, UiO-66 with distinct macropores and mesopores were intentionally created and served as substrates to create advanced CdS/UiO-66 catalysts. The pore size impacted the spatial distribution of CdS nanoparticles (NPs): CdS tended to deposit on the external surface of mesoporous UiO-66, but spontaneously penetrated into the large cavity of macroporous UiO-66 nanocage. Normalized to unit amount of CdS, the photocatalytic reaction constant of macroporous CdS/UiO-66 over 4-nitroaniline reduction was similar to 3 folds of that of mesoporous counterpart, and outperformed many other reported state-of-art CdS-based catalysts. A confinement effect of CdS NPs within UiO-66 cage could respond for its high activity, which could shorten the electron-transport distance of NPs-MOFs-reactant, and protect the active CdS NPs from photocorrosion. The finding here provides a straightforward paradigm and mechanism to rationally fabricate advance NPs/ MOFs for diverse applications. (C) 2021, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

The study investigated the pore size effect of metal organic framework UiO-66 on the performance of CdS/UiO-66 catalysts, revealing the distribution differences of CdS nanoparticles in UiO-66 with different pore sizes. It was demonstrated that the macroporous CdS/UiO-66 catalyst exhibited higher activity compared to the mesoporous counterpart.