Ran Du

Robust Superhydrophobic Foam: A Graphdiyne-Based Hierarchical Architecture for Oil/Water Separation

Robust superhydrophobic foam is fabricated by combining an ordered graphdiyne-based hierarchical structure with a low-surface-energy coating. This foam shows not only superhydrophobicity both in air (≈160.1°) and in oil (≈171.0°), but also high resistance toward abrasion cycles. Owing to its 3D porous structures and numerous superhydrophobic surfaces, it can easily separate oil from water with high efficiency and good recyclability.

Three-Dimensional Nitrogen-Doped Graphene Nanoribbons Aerogel as a Highly Efficient Catalyst for the Oxygen Reduction Reaction

A highly conductive, ultralight, neat and versatile nitrogen-doped GNRs aerogel has been fabricated by a new hydrothermal method for the first time. The newly developed aerogel shows a very promising performance when used as a novel ORR catalyst in both alkaline and acidic solutions.

Scalable Seashell-Based Chemical Vapor Deposition Growth of Three-Dimensional Graphene Foams for Oil–Water Separation

A seashell-based CVD technique for preparing three-dimensional (3D) graphene foams is reported. The graphene sheets in thus-obtained foams are seamlessly interconnected into a 3D flexible network, forming highly porous materials with negligible non-carbon impurities, ultralow density, and outstanding mechanical flexibility and electrical conductivity. These 3D graphene foams demonstrate a fast adsorption performance toward various oils and organic solvents, with adsorption capacity up to 250-fold weight gain. The present approach offers a practical route for scalable construction of 3D graphene foams for versatile applications such as energy storage and water remediation.

CMP Aerogels: Ultrahigh‐Surface‐Area Carbon‐Based Monolithic Materials with Superb Sorption Performance

Monolithic conjugated microporous polymer (CMP) aerogels are obtained in an extremely facile way by selection of adequate reaction conditions and a freeze-drying technique. The aerogels possess an ultrahigh specific surface area and hierarchical interconnected pores, exhibiting superb gas/oil adsorption performance compared with all microporous organic polymers to date.

Microscopic Dimensions Engineering: Stepwise Manipulation of the Surface Wettability on 3D Substrates for Oil/Water Separation.

Microscopic dimensions engineering is proposed to devise a series of 3D superhydrophobic substrates with microstructures of different dimensions. Combined theoretical modeling and experiments give the relationship of surface roughness and superhydrophobic properties, important for guiding the design of superior superwettable materials for water remediation and other uses.

Hierarchical Hydrogen Bonds Directed Multi‐Functional Carbon Nanotube‐Based Supramolecular Hydrogels

Supramolecular hydrogels (SMHs) are three-dimensional networks filled with a large amount of water. The crosslinking force in the 3D network is always constructed by relatively weak and dynamic non-covalent interactions, and thus SMHs usually possess extremely high susceptibility to external environment and can show extraordinary stimuli-responsive, self-healing or other attractive properties. However, the overall crosslinking force in hydrogel networks is difficult to flexibly modulate, and this leads to limited functions of the SMHs. In this regard, hierarchical hydrogen bonds, that is, the mixture of relatively strong and relatively weak hydrogen bonds, are used herein as crosslinking force for the hydrogel preparation. The ratio of strong and weak hydrogen bonds can be finely tuned to tailor the properties of resultant gels. Thus, by delicate manipulation of the overall crosslinking force in the system, a hydrogel with multiple (thermal, pH and NIR light) responsiveness, autonomous self-healing property and interesting temperature dependent, reversible adhesion behavior is obtained. This kind of hierarchical hydrogen bond manipulation is proved to be a general method for multiple-functionality hydrogel preparation, and the resultant material shows potential for a range of applications.

Synthesis of conducting polymer hydrogels with 2D building blocks and their potential-dependent gel–sol transitions

Conducting polymer hydrogels with unusual 2D building blocks were synthesized in one step via a combination of oxidative coupling polymerization and non-covalent crosslinking of an amphiphilic thiophene derivative. Chemicals with standard electrode potentials higher than 0.8 V triggered disbanding of the resulting conducting polymer hydrogels, indicating the occurrence of potential-dependent gel-sol transitions.

Macroscopic Carbon Nanotube‐based 3D Monoliths

Carbon nanotubes (CNTs) are one of the most promising carbon allotropes with incredible diverse physicochemical properties, thereby enjoying continuous worldwide attention since their discovery about two decades ago. From the point of view of practical applications, assembling individual CNTs into macroscopic functional and high-performance materials is of paramount importance. For example, multiscaled CNT-based assemblies including 1D fibers, 2D films, and 3D monoliths have been developed. Among all of these, monolithic 3D CNT architectures with porous structures have attracted increasing interest in the last few years. In this form, theoretically all individual CNTs are well connected and fully expose their surfaces. These 3D architectures have huge specific surface areas, hierarchical pores, and interconnected conductive networks, resulting in enhanced mass/electron transport and countless accessible active sites for diverse applications (e.g. catalysis, capacitors, and sorption). More importantly, the monolithic form of 3D CNT assemblies can impart additional application potentials to materials, such as free-standing electrodes, sensors, and recyclable sorbents. However, scaling the properties of individual CNTs to 3D assemblies, improving use of the diverse, structure-dependent properties of CNTs, and increasing the performance-to-cost ratio are great unsolved challenges for their real commercialization. This review aims to provide a comprehensive introduction of this young and energetic field, i.e., CNT-based 3D monoliths, with a focus on the preparation principles, current synthetic methods, and typical applications. Opportunities and challenges in this field are also presented.

Density controlled oil uptake and beyond: from carbon nanotubes to graphene nanoribbon aerogels

Large-scale manipulation of the density (from 2.5 to 1327 mg cm−3) and wettability of carbon-based aerogels has been realized by delicately modulating the gelation, drying and post-treatment processes. An unexpected “Janus face” effect of pyrrole was revealed in the fabrication process. Pyrrole acts as a “spacer” at relatively low concentrations ( ca. 5 vol%), leading to an increase of the aerogel density. By using systematic studies, the oil adsorption capacity of aerogels has been correlated with the aerogel density and surface wettability, which can guide the production of highly efficient sorbents. For example, a polydimethylsiloxane modified graphene nanoribbons aerogel with a density of 2.5 mg cm−3 was prepared and showed a remarkable adsorption capacity of up to 302 times for phenixin and 121 times for n-hexane its own weight, much higher than that of most carbonaceous sorbents previously reported. Furthermore, a proof-of-concept aerogel-based floating-type densitometer has also been proposed to expand the potential applications of aerogels.

Direct Synthesis of Graphdiyne Nanowalls on Arbitrary Substrates and Its Application for Photoelectrochemical Water Splitting Cell

A general and simple route to fabricate graphdiyne nanowalls on arbitrary substrates is developed by using a copper envelope catalysis strategy. The GDY/BiVO4 system is but one example of combing the unique properites of GDY with those target substrates where GDY improves the photoelectrochemical performance dramatically.