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Page 12 of 16 Feng et al. Chem Synth 2023;3:37 https://dx.doi.org/10.20517/cs.2023.26

Figure 8. Schematic illustration showing the proposed general template-free strategy for 2DMMs. This figure is quoted with permission
from Kaneti et al. [73] . 2DMMs: Two-dimensional mesoporous materials.

including molecular self-assembly methods, single micelle assembly methods, multi-templates methods,
SLCA methods, and template-free methods. Through these methods, various 2DMMs with adjustable sizes
and morphology have been achieved.

A molecular self-assembly method is a general method for the controlled synthesis of 2DMMs with ordered
porous structures, which can realize the precise control of the composition, coordination environment, and
nanostructure of the designed catalyst. The single micelle method can achieve the preparation of ultra-thin
monolayer mesoporous structures by precise self-assembly at the level of a single micelle. The multi-
templates method relies on the preparation of mesoporous inorganic/organic layers on 2D-oriented
substrates and is suitable for the preparation of planar mesoporous nanosheets or sandwich mesoporous
heterostructures. SLCA is suitable for preparing 2DMMs with highly open porous structures, short diffusion
distances, and easy access to the active site. Template-free methods are often used to prepare disordered
2DMMs due to their lack of ability to control pore sizes and structures. The comparison of the currently
available synthetic methods toward 2DMMs is as follows [Table 1].

Compared to homologous 2D non-mesoporous materials and bulk mesoporous materials, the unique
features of 2DMMs, such as larger lateral sizes, abundant active sites, thinner thickness, and more open pore
channels, improve the performance of materials in applications such as energy storage, catalysis, and so on.
In addition, 2DMMs with different structures can endow materials with different application prospects. For
example, sandwich-like mesoporous heterostructures of medium-thickness 2DMMs can balance the
content of functional components and 2D substrates and maximize their application properties. 2DMMs
with vertical spherical pores typically have larger specific surface areas, thereby exhibiting higher specific
capacitance and energy density in the electrochemical field. Disordered 2DMMs possess interconnected
mesoporous and larger specific surface areas and thus enhanced mass/ion transfer efficiency, while ordered
mesoporous can endow 2DMMs with controllable morphology, special functions, and adjustable
application properties.

However, 2DMMs are still in their early stages, and there are the following development issues that need to
be addressed urgently. Firstly, although there have been encouraging developments in the designed
synthesis of 2DMMs, their chemical compositions and synthesis strategies still cannot meet the
requirements. In order to obtain 2DMMs with accurate synthetic composition, geometric shape, and
controllable pore sizes, it is urgent to explore simpler and more universal synthesis methods and deeply
understand their formation mechanisms. Secondly, current research on 2DMMs mainly focuses on
commonly used polymers (such as polypyrrole, polydopamine, and polydiaminopyridines), carbon
(including graphene), oxides (such as SiO and TiO ), and their hybrids. It can be predicted that with the
2
2
development of ordered mesoporous atomic sheets, new type 2DMMs (such as carbides, nitrides, sulfides,
phosphides, selenide, and metal/covalent organic frameworks) with diverse single or multi-component