Materials and devices for separation, sensing, and protection

The synthesis of three-dimensional (3D) covalent organic frameworks (COFs) with highly connected building blocks presents a significant challenge. Here, the authors report the synthesis of two 3D COFs with the nia topology, by introducing planar hexagonal and triangular prism nodes.

The challenge of trace CO removal from H₂ remains at the forefront of the hydrogen economy. Here, the authors demonstrated exceptional CO removal using a highly stable, hierarchically structured sorbent bead, Mg₁₃CuCeOx. Mechanistic analysis showed the pivotal role of Mg in enhancing CO sorption.

One-step separation of C2H4 from ternary C2 hydrocarbon mixtures remains a challenge for current physisorbents. Here, the authors reported a strategy of designing multiple supramolecular binding sites in a robust and scalable MOF for highly efficient one-step C2H4 purification from ternary mixtures.

Synthetic framework materials are appealing candidates for the fabrication of separation membranes but realizing precise control of aperture distribution and separation threshold remains challenging. Here, the authors show a two-dimensional processible supramolecular framework which can be used in the fabrication of separation membranes by integrating directional organic host-guest motifs and inorganic functional polyanionic clusters.

Eco-friendly, efficient, and selective gold recovery technologies are urgently desired to satisfy the increasing demand for gold. Here, the authors report one such technology based on the supramolecular polymerization of second-sphere coordinated adducts formed between β-cyclodextrin and tetrabromoaurate anions.

Supramolecular chemistry based on cyclodextrin receptors as second-sphere ligands contribute to developing non-covalent materials with synergistic functionalities. Herein, we comment on a recent investigation of this concept, describing selective gold recovery through a hierarchical host-guest assembly specifically built from β-CD.

Silver ions in wastewater are a major health hazard, and there is an urgent need to develop methods to reliably extract them. Here, the authors show that mixed-valence molybdenum oxide can selectively adsorb and reduce Ag⁺ from wastewater and be easily recycled while maintaining high selectivity towards Ag⁺.

Efficient and selective gold recovery from electronic waste is highly demanded. Here, authors demonstrate the application of a porous organic polycarbene adsorbent with up to 2.09 g/g gold-capturing capability.

The evolution of the chemical and pharmaceutical industry requires effective and less energy intensive separation technologies but engineering materials at a large scale with tunable properties for molecular separation is challenging. Here, the authors report a thin film composite membranes prepared by the interfacial polymerization of porous organic cages.

Transition metal-based homogenous photocatalysts are important in organic synthesis, but the metals used can be rare and immobilization of the catalysts for recycling is challenging. Here, the authors report the recovery of such catalysts using covalent organic framework membranes with tuneable pore sizes.

The synthesis of sp² carbon-conjugated covalent organic frameworks is limited to a few reactions and monomers due to the poor irreversibility of carbon double bonds. Here the authors synthesize propenone-linked covalent organic frameworks for the removal of radionuclide uranium from mine wastewater samples.

Achieving highly selective separation of olefin/paraffin is a significant challenge in the chemical industry. Here the authors present polydopamine-derived carbons with tailorable sub-5 Å micropores probed by a series of gas molecules that can realize precise size-sieving of olefin from paraffin.

Ethylene (C₂H₄) purification from multi-component mixtures by physical adsorption is a great challenge in the chemical industry. Here authors present a GeF6^2- anion embedded MOF ZNU-6 with customized pore structure and pore chemistry for benchmark one-step C₂H₄ recovery from C₂H₂ and CO₂ with record C₂H₄ productivity.

The design and scalable fabrication of durable superhydrophobic coatings that prevent accretion of matter is challenging. Here the authors developed a generic cellular design for ultra-durable coatings that provides liquid-repellence, vapor imperviousness, and solid-shedding capabilities.

Hydrophobic condenser surfaces can improve power plant efficiency, but they suffer from poor durability. Here the authors developed a durable fluorinated diamond-like carbon coating that improved dropwise condensation and maintained hydrophobicity over three years of pure steam condensation on multiple metallic substrates.

Good impalement resistance, mechanical robustness and weather resistance are essential for applications of superhydrophobic coatings. Here, the authors achieve scalable preparation and practical application of robust superhydrophobic coatings for preventing rain attenuation of 5G/weather radomes.

2D COFs are promising for resistance-related applications, but usually form powders where poor contacts at grain boundaries inhibit the conductivity. Here authors show that halide perovskites can act as electric glues to bond 2D COFs to improve their conductivity, activating them to detect NO₂ with high selectivity and sensitivity.

Conventional nanochannel sensors are passively responsive and may be slowly damaged by analytes present in the environment before detection. Here, authors developed a light-controlled inert/active-switchable biomimetic nanochannel sensor to achieve SO₂ on-demand detection and long-term preservation.

NO₂ monitoring is important in urban areas where pollutant levels are typically higher. Here authors present a hybrid structure of laser-induced graphene and Cu₃HHTP₂, a 2D semiconducting MOF, for highly sensitive and rapid detection of NO₂ at the parts-per-billion level.

3D fabrication via mechanically guided assembly has greatly progressed in the recent years, but has not been applicable for nanodevices. Here the authors suggest a configuration-designable 3D nanofabrication through a nanotransfer printing and design of the substrate’s mechanical characteristics.

Bilayer sensors and sensor arrays with a catalytic CeO2 filter are proposed as a facile platform for high-performance gas sensors and electronic noses. Authors show the bilayer sensors enhance selectivity toward aromatic compounds, and the arrays provide comprehensive information such as gas concentration and composition.

The application of multivariate gas sensors is limited due to their size and cost. Here the authors developed a compact gas sensor with multiple chemiresistive and potentiometric readouts enabling 3D discriminative response of gases at (sub)ppm levels and used the sensor for early fire detection.

Developing fast-responsive NH3 sensors at room temperature is challenging. Here the authors developed robust Hoffmann-type MOF based NH3 sensors with a low detection limit (25 ppb) and quick response (5 s). The sensors exhibit high NH3 selectivity, stability, and easy recovery.

The design and scalable fabrication of durable superhydrophobic coatings that prevent accretion of matter is challenging. Here the authors developed a generic cellular design for ultra-durable coatings that provides liquid-repellence, vapor imperviousness, and solid-shedding capabilities.

Synthetic materials that can repeatedly self-repair, akin to biological systems, are vital to meeting the 21st century’s infrastructural demands. Here, authors develop fiber-reinforced composites with rapid and prolonged in situ self-healing while also preserving structural integrity.

The high solar reflectance needed by radiative cooling is easily dampened by environmental aging. Here, authors describe durable cooling performance against heavy soiling and long-term ultraviolet exposure of paint-based coatings, enhancing the potential of radiative cooling for real-world applications.

The efficiency of CoSb_x (where 2 < x < 3) as a selective solar absorber is investigated. Here, authors demonstrate that CoSbx endows broadband solar absorption (0.96) and simultaneous low emissivity (0.18), making it a promising material for use in solar energy systems.

There is an urgent need to develop coatings with good neutron-absorption capacity and workability. Here the authors addressed these challenges by developing a scalable and solution processable two-dimensional Ti₃C₂T_x MXene hybrid film with homogeneously distributed B₄C particles.

Mechanically robust, flexible and thermally insulating ceramic aerogels are challenging to obtain due to the conflicting nature of these properties. Here the authors resolved these contradictions and developed a strong yet flexible aerogel, for application in extreme conditions, by laminated structure design.

Heterointerface and defect promote the development of electromagnetic wave absorbers. Here, the authors show the 3D flower-honeycomb CuCo₂S₄@Expanded Graphite heterostructure, report the mechanism of crystal-crystal/amorphous heterointerfaces and cation defects on electromagnetic wave absorption.

Instability of perovskites under light, moisture and temperature stress hinders their potential in real applications. Here Tian et al. demonstrate the high-throughput fabrication of large-area, flexible, color-tunable, waterproof and durable wearable luminescent textiles suitable for marine rescue.

Carbon aerogels are generally fragile and tend to collapse under large compressive strain. Here, the authors demonstrate that the mechanical strength, elasticity, and fatigue resistance can be improved by fabricating aerogels with interconnected carbon tubes.

Silica glass is a high-performance material used in most branches of society from glassware and windows to optical lenses and fibers. Here, we develop a sintering-free method for 3D printing silica glass with sub-micrometer resolution and successfully demonstrate an optical microtoroid resonator.

There is an urgent need to develop efficient strategies to remove elemental mercury from industrial flue gases. Here the authors develop a simple, versatile, and scalable strategy to obtain a 100-fold enhancement of the elemental mercury accommodation capacities of a wide range of transition metal sulfides by in situ acid etching.

Adopting standardized and reliable methodologies to accurately measure particle removal efficiency when developing fibrous materials for controlling airborne contamination is crucial. Here, the authors recommend best practices for experimental assessments and reporting to ensure a reliable evaluation of new airborne particle filtration media and technologies.

Exploiting the electrical and mechanical properties of CNT films remain elusive because of the difficult material process. Here, Wang et al. report multifunctional MWCNT films with crystalline structure which exhibited great electromagnetic interference shielding efficiency, high thermoelectric power factor, and large ampacity.

Converting natural wood to room temperature phosphorescent (RTP) materials is a complex process often requiring toxic reagents. Here the authors convert natural wood to a RTP material using external chloride ions from a MgCl2 solution, obtaining a promising luminescent additive material for 3D printing.