Metal or metal-containing nanoparticle@MOF nanocomposites as a promising type of photocatalyst

Photocatalysis is a promising technology that can convert solar energy into chemical energy. However, developing photocatalyst that could be put into the practical application remains a big challenge worldwide. In the recent years, an emerging type of core-shell/core-shell like composites, in which the metal or metal-containing nanoparticles (M/MC NPs) cores are encapsulated by the metal-organic frameworks (MOFs) shells, have attracted increasing attention in photocatalysis. These M/MC NP@MOF nanocomposites are believed to be one of the most effective and convenient ways to achieve property synergies of MOFs and M/MC NPs. Even though this field is currently in its infancy, the promising results obtained have validated the potential use of M/MC NP@MOF nanocomposites in practical applications. In this review, the fundamental mechanisms of photocatalysis were briefly introduced. The synthesis of M/MC NP@MOF nanocomposites and related photocatalytic applications (such as photocatalytic hydrogen generation and Cr(VI) reduction) are summarized and exemplified. Special emphasis is given to the synergistic effects between the MOFs shell and NPs core that result in an enhanced performance in heterogeneous photocatalysis. Finally, the unsolved problems of M/MC NP@MOF nanocatalysts are discussed and the future development prospects are proposed. (C) 2019 Elsevier B.V. All rights reserved.