This Account is focused primarily on surveying the strategies for constructing porous 3D HOFs based on organic building blocks with peripheral carboxyl groups. We identify the development of novel hydrogen-bonding motifs such as diaminotriazine (DTA), the introduction of the concept of molecular tectonics, and the establishment of permanent porosity in HOFs as being some of the milestones, which incentivized the current burgeoning research endeavors on developing HOFs as multifunctional materials. In this paper, we, first of all, provide an overview of the chronological development of HOFs, starting from the seminal work by Marsh and Duchamp in 1969 on the crystal superstructure of the hydrogen-bonded networks of trimesic acid. The applications of HOFs are far-reaching, spanning catalysis, energy, and biomedical products as well as the storage and separation of fine chemicals. During the past decade, considerable progress has been achieved in realizing stable HOFs with permanent porosities by focusing on the design of more » molecular building blocks in order to introduce rigidity, auxiliary interactions, and interpenetration of their frameworks to sustain the extended networks. High-quality single crystals of HOFs can be grown easily for unambiguous superstructure determination by single-crystal X-ray diffraction, which is crucial for the elucidation of superstructure–property relationships. The reversible nature of the hydrogen-bond formation endows HOFs with the attributes of solution processability and simple regeneration. Hydrogen-bonded organic frameworks (HOFs) are a class of porous molecular materials that rely on the assembly of organic building blocks by means of hydrogen-bonding interactions to form two-dimensional (2D) and three-dimensional (3D) crystalline networks. (ANL), Argonne, IL (United States) Sponsoring Org.: National Natural Science Foundation of China (NSFC) USDOE Office of Science (SC) Natural Science Foundation of Heilongjiang Province for Distinguished Young Scholars OSTI Identifier: 1843611 Grant/Contract Number: AC02-06CH11357 21878062 JQ2020B001 Resource Type: Accepted Manuscript Journal Name: Materials Today Additional Journal Information: Journal Volume: 51 Journal ID: ISSN 1369-7021 Publisher: Elsevier Country of Publication: United States Language: English Subject: 36 MATERIALS SCIENCE asymmetry directional transport multifunction integration porous Janus = , Publication Date: Fri Aug 13 00:00: Research Org.: Argonne National Lab. Advanced Materials for Energy-Water Systems (AMEWS) Argonne National Lab.

Energy Frontier Research Centers (EFRC) (United States).

of Critical Materials Technology for New Energy Conversion and Storage Harbin Inst. of Critical Materials Technology for New Energy Conversion and Storage Energy Frontier Research Centers (EFRC) (United States). of Critical Materials Technology for New Energy Conversion and Storage Finally, ongoing challenges and outlook for the future research of porous Janus materials are presented. This in-depth review systematically analyzes the research progress of porous Janus materials, highlighting fabrication strategies, synergistic/independent work mechanisms, and emerging advanced applications.

Additionally, compared with conventional homogeneous materials, porous Janus materials not only showcase superior performance and energetic potential but also open up new applications by virtue of the synergistic or independent effects of asymmetry.

Multifunction integration and unique directional manipulation of liquid, ions, or gas within porous Janus materials enable rapid progress in diverse applications such as water-oil separation, fog collection, personal moisture and healthcare management, energy conversion, desalination, sensor devices, and biomedical applications. Porous Janus materials have attracted widespread attention due to their asymmetry in wettability, charge, pore size or structure, thermal/electrical conductivity, and chemical activity, among other properties.

Jingwei wan