posted on 2024-02-09, 22:12authored byHengyu Lin, Yihao Yang, Kelechi Williams Festus, Yu-Chuan Hsu, Rong-Ran Liang, Ibukun Afolabi, Hong-Cai Zhou
ConspectusThis Account aims to concisely
summarize recent advancements in
the field of photocatalysis, with a particular focus on dimension-reduced
metal–organic nanomaterials, including coordination cages and
2D structures. Metal–organic frameworks (MOFs), known for their
high crystallinity, porosity, and well-determined structures, are
at the forefront of this research. They offer a unique confined environment
that is optimal for enhancing host–guest interactions. This,
in turn, leads to highly selective and efficient catalytic reactions.
The ability of MOFs to provide a structured and controlled environment
has revolutionized the way we approach catalytic processes, especially
in terms of efficiency and selectivity. However, a significant challenge
that has emerged in the use of traditional 3-dimensional bulk MOFs
is their limitation in mass transport. This limitation often results
in reduced catalytic efficiency, hindering their practical applicability
in industrial scenarios. To address these challenges, researchers
have taken a novel turn toward exploring 0-dimensional (0D) porous
coordination cages and 2-dimensional (2D) MOF-derived nanosheets.
These structures exhibit improved mass transport capabilities and
more exposed catalytic centers, thereby circumventing the issues faced
by their 3D counterparts. These structures have shown great promise
in overcoming the limitations of pore clogging, a common issue in
3D MOFs, thus paving the way for more efficient and scalable catalytic
processes.Section 2 of our paper delves deeper into the design
and functionalities
of cages and 2D MOF nanosheets. This section is particularly focused
on the theoretical and technical approaches necessary to understand
and utilize these materials effectively. We discuss various methods,
including studying redox cycles through electrochemical and photochemical
methods, and exploring the intricate dynamics of host–guest
chemistry. Additionally, this section highlights the latest spectroscopic
and computational techniques that have been instrumental in recent
research efforts. These techniques have enabled scientists to investigate
active sites within MOFs, thereby providing deeper insights into their
catalytic mechanisms and potential applications. In section 3 of this
Account, we provide a discussion on the design and availability of
these photoactive ligands and framework materials. In addition to
structural innovations, this account also delves into the realm of
introducing small-molecule organic photocatalysts. This section is
pivotal in understanding the underlying chemistry and the innovative
approaches employed in the development of these materials. We elaborate
on the synthetic methodologies, the choice of functional groups, and
the potential applications of these novel materials. Despite their
inherent challenges, such as short excited-state lifespans and difficulties
in recycling, these photocatalysts have shown a vast potential for
effective photochemical transformations. By integrating these small
molecules into the 0D and 2D frameworks, chemists have been able to
significantly enhance their efficiency and stability.In conclusion,
this Account aims to elucidate the design principles
of 0D and 2D MOF nanomaterials, explore reliable characterization
techniques, and inspire the development of novel catalysts. The goal
is to achieve catalysts with heightened selectivity and activity,
which can revolutionize various industrial processes and contribute
to sustainable development. Through this comprehensive overview, we
hope to provide a foundational understanding for future research in
this rapidly evolving field, guiding new discoveries and innovations.