The discovery of graphene has triggered great interest in two-dimensional (2D) nanomaterials for scientists in chemistry, physics, materials science, and related areas. In the family of newly developed 2D nanostructured materials, 2D soft nanomaterials, including graphene, B_xC_yN_z nanosheets, 2D polymers, covalent organic frameworks (COFs), and 2D supramolecular organic nanostructures, possess great advantages in light-weight, structural control and flexibility, diversity of fabrication approaches, and so on. These merits offer 2D soft nanomaterials a wide range of potential applications, such as in optoelectronics, membranes, energy storage and conversion, catalysis, sensing, biotechnology, etc. This review article provides an overview of the development of 2D soft nanomaterials, with special highlights on the basic concepts, molecular design principles, and primary synthesis approaches in the context.

Combining the advantages from both porous materials and graphene, porous graphene materials have attracted vast interests due to their large surface areas, unique porous structures, diversified compositions and excellent electronic conductivity. These unordinary features enable porous graphene materials to serve as key components in high-performance electrochemical energy storage and conversion devices such as lithium ion batteries, supercapacitors, and fuel cells. This progress report summarizes the typical fabrication methods for porous graphene materials with micro-, meso-, and macro-porous structures. The structure–property relationships of these materials and their application in advanced electrochemical devices are also discussed.

2D MoS₂ nanosheets have been utilized to fabricate 2D MoS₂/CdS p–n nanohybrids through a one-pot solvothermal process. Due to the unique p–n junction heterostructure, large specific surface area, and decreased band gap, MoS₂/CdS nanohybrids manifested a superior H₂-production rate of ∼137 μmol h⁻¹ under visible-light irradiation and an apparent quantum yield of 10.5 % at 450 nm.

A bottom-up approach toward stable and monodisperse segments of graphenes with a nitrogen-doped zigzag edge is introduced. Exemplified by the so far unprecedented dibenzo-9a-azaphenalene (DBAPhen) as the core unit, a versatile synthetic concept is introduced that leads to nitrogen-doped zigzag nanographenes and graphene nanoribbons.

A water-soluble surfactant consisting of hexa-peri-hexabenzocoronene (HBC) as hydrophobic aromatic core and hydrophilic carboxy substituents was synthesized. It exhibited a self-assembled nanofiber structure in the solid state. Profiting from the π interactions between the large aromatic core of HBC and graphene, the surfactant mediated the exfoliation of graphite into graphene in polar solvents, which was further stabilized by the bulky hydrophilic carboxylic groups. A graphene dispersion with a concentration as high as 1.1 mg L⁻¹ containing 2–6 multilayer nanosheets was obtained. The lateral size of the graphene sheets was in the range of 100–500 nm based on atomic force microscope (AFM) and transmission electron microscope (TEM) measurements.

Nitrogen-doped carbon nanosheets (NDCN) with size-defined mesopores are reported as highly efficient metal-free catalyst for the oxygen reduction reaction (ORR). A uniform and tunable mesoporous structure of NDCN is prepared using a templating approach. Such controlled mesoporous structure in the NDCN exerts an essential influence on the electrocatalytic performance in both alkaline and acidic media for the ORR. The NDCN catalyst with a pore diameter of 22 nm exhibits a more positive ORR onset potential than that of Pt/C (−0.01 V vs. −0.02 V) and a high diffusion-limited current approaching that of Pt/C (5.45 vs. 5.78 mA cm⁻²) in alkaline medium. Moreover, the catalyst shows pronounced electrocatalytic activity and long-term stability towards the ORR under acidic conditions. The unique planar mesoporous shells of the NDCN provide exposed highly electroactive and stable catalytic sites, which boost the electrocatalytic activity of metal-free NDCN catalyst.

We demonstrate a general and efficient self-templating strategy towards transition metal–nitrogen containing mesoporous carbon/graphene nanosheets with a unique two-dimensional (2D) morphology and tunable mesoscale porosity. Owing to the well-defined 2D morphology, nanometer-scale thickness, high specific surface area, and the simultaneous doping of the metal–nitrogen compounds, the as-prepared catalysts exhibits excellent electrocatalytic activity and stability towards the oxygen reduction reaction (ORR) in both alkaline and acidic media. More importantly, such a self-templating approach towards two-dimensional porous carbon hybrids with diverse metal–nitrogen doping opens up new avenues to mesoporous heteroatom-doped carbon materials as electrochemical catalysts for oxygen reduction and hydrogen evolution, with promising applications in fuel cell and battery technologies.

Nitrogen-doped carbon nanosheets (NDCN) with size-defined mesopores are reported as highly efficient metal-free catalyst for the oxygen reduction reaction (ORR). A uniform and tunable mesoporous structure of NDCN is prepared using a templating approach. Such controlled mesoporous structure in the NDCN exerts an essential influence on the electrocatalytic performance in both alkaline and acidic media for the ORR. The NDCN catalyst with a pore diameter of 22 nm exhibits a more positive ORR onset potential than that of Pt/C (−0.01 V vs. −0.02 V) and a high diffusion-limited current approaching that of Pt/C (5.45 vs. 5.78 mA cm⁻²) in alkaline medium. Moreover, the catalyst shows pronounced electrocatalytic activity and long-term stability towards the ORR under acidic conditions. The unique planar mesoporous shells of the NDCN provide exposed highly electroactive and stable catalytic sites, which boost the electrocatalytic activity of metal-free NDCN catalyst.

3D hierarchical tin oxide/graphene frameworks (SnO₂/GFs) were built up by the in situ synthesis of 2D SnO₂/graphene nanosheets followed by hydrothermal assembly. These SnO₂/GFs exhibited a 3D hierarchical porous architecture with mesopores (≈3 nm), macropores (3–6 μm), and a large surface area (244 m² g⁻¹), which not only effectively prevented the agglomeration of SnO₂ nanoparticles, but also facilitated fast ion and electron transport in 3D pathways. As a consequence, the SnO₂/GFs exhibited a high capacity of 830 mAh g⁻¹ for up to 70 charge–discharge cycles at 100 mA g⁻¹. Even at a high current density of 500 mA g⁻¹, a reversible capacity of 621 mAh g⁻¹ could be maintained for SnO₂/GFs with excellent cycling stability. Such performance is superior to that of previously reported SnO₂/graphene and other SnO₂/carbon composites with similar weight contents of SnO₂.

On the basis of our previous communication concerning a new family of thiophene-armed tetraazaanthracene molecules, we present a further intensive investigation on this class of compounds substituted with different alkyl chains and their self-assembled two-dimensional (2D) nanostructures. These tetraazaanthracene molecules with different alkyl chains were prepared in good yields using the synthetic strategy we developed. In addition to the expected typical n-type character, one compound exhibited aggregation behavior upon electrochemical reduction. Moreover, all molecules in the neutral state showed a strong tendency to aggregate in a binary solvent, as confirmed by optical spectral measurements. To investigate such self-assembly behavior, a phase-transfer method with a dichloromethane/methanol (2:3) binary solvent system was used to prepare the nanostructures. By means of atomic force microscopy, transmission electron microscopy, and X-ray diffraction, we found that the morphology of assembled 2D sheet-like structures could be adjusted by varying the alkyl chain. The weak interactions arising from the heteroatoms (N and S) in the conjugated backbones play a key role in the formation and stabilization of layered structures.

Heteroatom (N or S)-doped graphene with high surface area is successfully synthesized via thermal reaction between graphene oxide and guest gases (NH₃ or H₂S) on the basis of ultrathin graphene oxide-porous silica sheets at high temperatures. It is found that both N and S-doping can occur at annealing temperatures from 500 to 1000 °C to form the different binding configurations at the edges or on the planes of the graphene, such as pyridinic-N, pyrrolic-N, and graphitic-N for N-doped graphene, thiophene-like S, and oxidized S for S-doped graphene. Moreover, the resulting N and S-doped graphene sheets exhibit good electrocatalytic activity, long durability, and high selectivity when they are employed as metal-free catalysts for oxygen reduction reactions. This approach may provide an efficient platform for the synthesis of a series of heteroatom-doped graphenes for different applications.

Graphen, eine einzelne, zweidimensionale Graphitschicht aus einem hexagonalen Netzwerk von sp²-hybridisierten Kohlenstoffatomen, ist wegen seiner außergewöhnlichen elektronischen, thermischen und mechanischen Eigenschaften ein vielversprechender Kandidat für praktische Anwendungen in Elektronik, Sensorik, Katalyse sowie Energiespeicherung und -umwandlung. Theoretische und experimentelle Untersuchungen zeigten, dass die Eigenschaften von Graphen im Wesentlichen von dessen geometrischen Struktur abhängen. Eine zielgerichtete Graphensynthese ist daher für eine Untersuchung der grundlegenden physikalischen Eigenschaften und Implementierung in vielversprechende Anwendungen entscheidend. Dieser Kurzaufsatz präsentiert jüngste Fortschritte, die zu erfolgreichen chemischen Synthesen von Graphen in einem breiten Bereich von Größen und chemischen Zusammensetzungen geführt haben.

Graphene, an individual two-dimensional, atomically thick sheet of graphite composed of a hexagonal network of sp² carbon atoms, has been intensively investigated since its first isolation in 2004, which was based on repeated peeling of highly oriented pyrolyzed graphite (HOPG). The extraordinary electronic, thermal, and mechanical properties of graphene make it a promising candidate for practical applications in electronics, sensing, catalysis, energy storage, conversion, etc. Both the theoretical and experimental studies proved that the properties of graphene are mainly dependent on their geometric structures. Precise control over graphene synthesis is therefore crucial for probing their fundamental physical properties and introduction in promising applications. In this Minireview, we highlight the recent progress that has led to the successful chemical synthesis of graphene with a range of different sizes and chemical compositions based on both top-down and bottom-up strategies.

The multiple functional groups and unique two-dimensional (2D) morphology make chemically modified graphene (CMG) an ideal template for the construction of 2D nanocomposites with various organic/inorganic components. Additionally, the recovered electrical conductivity of CMG may provide a fast-electron-transport channel and can thus promote the application of the resultant nanocomposites in optoelectronic and electrochemical devices. This Concept article summarizes the different strategies for the bottom-up fabrication of CMG-based 2D nanocomposites with small organic molecules, polymers, and inorganic nanoparticles, which represent the new directions in the development of graphene-based materials.