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Abstract Hierarchically porous materials containing sub-nm ultramicropores with molecular sieving abilities and microcavities with high gas diffusivity may realize energy-efficient membranes for gas separations. However, rationally designing and constructing such pores into large-area membranes enabling efficient H2 separations remains challenging. Here, we report the synthesis and utilization of hybrid carbon molecular sieve membranes with well-controlled nano- and micro-pores and single zinc atoms and clusters well-dispersed inside the nanopores via the carbonization of supramolecular mixed matrix materials containing amorphous and crystalline zeolitic imidazolate frameworks. Carbonization temperature is used to fine-tune pore sizes, achieving ultrahigh selectivity for H2/CO2 (130), H2/CH4 (2900), H2/N2 (880), and H2/C2H6 (7900) with stability against water vapor and physical aging during a continuous 120-h test.

Polylactic acid (PLA) and hydroxyapatite (HA) composite scaffolds have been widely studied for applications in bone tissue engineering (BTE) due to their bioactive and biocompatible properties. However, there is a need for more knowledge about the influence of size and crystallinity of HA nanoparticles (nHA) on the properties of PLA/nHA nanocomposite scaffolds produced by 3D printing. In this study, 3D printing was used to produce PLA nanocomposite scaffolds incorporated with nHA filler with different particle sizes and crystallinities. Initially, the nanocomposites were prepared by casting for 3D printing of scaffolds, which were characterized by analysis of thermal, morphological, physical-chemical, mechanical, and biological properties in vitro. The results showed that the size and crystallinity of nHA particles mainly influenced the scaffolds' mechanical properties, degradation rate, and bioactivity. Incorporating nHA provided a gain in compressive strength compared to pure PLA, superior to natural cancellous bone, which varies between 2 and 12 MPa. The lower crystallinity, 39.46 %, promoted a higher rate of degradation and bioactivity in vitro due to its solubility in the simulated fluid. All nanocomposite scaffolds showed cell viability above 90 %. The scaffolds showed suitable properties for BTE applications.

Cost effective modes of transport keeping in conjunction with sustainable outlooks for the future have ensured new technologies and initiatives being taken across the globe. Lighter electric vehicles including two-wheelers or scooters have risen in popularity, with both government and private backed industries investing heavily in green energy. Various state of the art energy systems has been discussed, along with unique approaches to ensure optimum efficiency and lifetime, such as preventing thermal runway reactions, and minimal degradation of electrodes. Supercapacitors, and hybrid fuel cells show potential to be adapted on large scale. New materials and approaches to synthesising​ the former have also been addressed, with emphasis on the powering of the next generation vehicles. Hybrid motor and engine setups developed over the last several years show great improvement and consume minimal quantity of energy. Clever braking technologies further showcase regenerative techniques and improve mileage. Fuel cost comparisons and recycling methodologies are seen to be researched extensively, while multiple challenges have been addressed. Major problems such as reducing carbon footprints and minimising several particulate pollutions present in the atmosphere are demonstrated to be overcome by implementation of electric two wheelers with regions like Europe and Asia showing the most promise in current times. This review will aim to integrate the individual functions and piece the whole system together. Analysis of future opportunities will allow for a comprehensive overview as well.

A family of single-atom catalysts synthesized by intercalating metal single atoms into the van der Waals gap of two-dimensional SnS2 is reported. The materials are applied as hydrogen evolving catalysts with good durability and overpotential.

Materials with correlated localisation of percolating particles and emergent conductive paths can realise sharp transitions and high conductivities characteristic of the explosively-grown network. Here the authors exploit explosive percolation to realize a low-loading composite material with enhanced electrical properties by in-situ reduction of graphene oxide.

Scale formation may have detrimental effects on the properties and functions of materials’ surfaces. Here the authors report the high scaling resistance of hexagonal boron nitride and relate it to the atomic level structure and interaction with water molecules.

Abstract To address the global energy and environmental crisis, advanced energy storage systems with their superior electrochemical performances have been growing exponentially. The electrochemical properties of the selected electrode materials have a direct impact on the performance of these energy storage technologies. 2D structures are considered promising materials for energy storage systems because of their unique and outstanding electrochemical characteristics. Therefore, hybridization of 2D nanosheets with other low‐dimensional materials can improve storage capacity by modulating and exploiting the synergy between the same. This comprehensive review highlights energy storage devices, their mechanisms, and key problems, with a focus on electrodes made of new generation 2D hybrids. Following that, the strategies that enable face‐to‐point, face‐to‐line, and face‐to‐face heterointerfaces are discussed in details. In addition, a design approach is provided for synergistically coupling 2D with other quantum materials for designing efficient and long‐lasting storage systems. It is anticipated that this review article will serve as helpful motivation for developing excellent energy storage devices with improved electrochemical capability.

Summary: Developing materials for controlled hydrogen production through water splitting is one of the most promising ways to meet current energy demand. Here, we demonstrate spontaneous and green production of hydrogen at high evolution rate using gadolinium telluride (GdTe) under ambient conditions. The spent materials can be reused after melting, which regain the original activity of the pristine sample. The phase formation and reusability are supported by the thermodynamics calculations. The theoretical calculation reveals ultralow activation energy for hydrogen production using GdTe caused by charge transfer from Te to Gd. Production of highly pure and instantaneous hydrogen by GdTe could accelerate green and sustainable energy conversion technologies.

E-skins currently suffer from issues to do with the predominantly non-biological materials they are made from. Here, the authors report on a gluten network which is cross-linked with EGaIn liquid metal to make a self-healing, biocompatible, biodegradable, stretchable and conductive material which is demonstrated as a movement strain sensor.

Non-noble transition metal oxides are common yet typically poor hydrogen evolution catalysts due to scarce active electronic states. This work provides a route for achieving hydrogen evolution at high current densities by stabilizing a metastable NiMoO4 phase with abundant active electronic states.

Electrochemical conversion of CO2 to fuels is a promising strategy to reduce the ever-increasing CO2 emission. Here, the authors developed graphene quantum dots (GQDs) catalysts to efficiently convert CO2 to CH4 and revealed the significance of electron-donating functional groups in regulating the reactivity of GQDs.

This paper presents a new modified electrode that combines the high electrical conductivity of carbon nanotubes (CNTs) with the catalytic sites of WS2 (named WS2/CNTs) for isoniazid detection. Electrochemical and electroanalytical properties of the WS2/CNTs/glassy carbon electrode (GCE)-modified electrodes were investigated by cyclic voltammetry and differential pulse voltammetry (DPV). The composite material was characterized by Raman spectroscopy, X-ray diffractometry (XRD), and scanning electron microscopy . The electrochemical performance of the WS2/CNTs/GCE sensor exhibited a limit of detection of 0.24 μM with a linear range from 10 to 80 μM of isoniazid using DPV. This sensor provided enhanced stability and electrocatalytic activity for isoniazid oxidation reactions. Recoveries ranging from 96.9 to 104.5% were calculated, demonstrating satisfactory accuracy of the proposed method. The improvement of electrochemical activity was assigned to synergic effects obtained by combining the catalytic sites from WS2 and the known electrical conductivity and large surface area of the CNTs, resulting in an anticipation of the oxidation peak of isoniazid in about 400 mV in comparison with bare GCE.

The deep cryogenic temperatures present significant challenges for the performance of elastic materials. Here, the authors present a low density covalently crosslinked polyimide (PI) aerogels with super-elastic properties at deep cryogenic temperatures.

Electron sources play as important component in a wide range of applications. Here, the authors demonstrate efficient, regenerative, and low-cost electron sources based on solution-processed halide perovskite thin films with quantum efficiency up to 2.2% and a lifetime of more than 25 h.

Metal-organic frameworks are promising for a range of applications, but architectural control is challenging. Here the authors use solvent-assisted ligand exchange to access a variety of metal-organic framework nanomaterials for precursors of nanoporous carbon with sodium ion storage properties.

Li-S batteries still suffer from two of the major challenges: polysulfide shuttle and low inherent conductivity of sulfur. Here, we report a facile way to develop a bifunctional separator coated with fluorinated multiwalled carbon nanotubes. Mild fluorination does not affect the inherent graphitic structure of carbon nanotubes as shown by transmission electron microscopy. Fluorinated carbon nanotubes show an improved capacity retention by trapping/repelling lithium polysulfides at the cathode, while simultaneously acting as the “second current collector”. Moreover, reduced charge-transfer resistance and enhanced electrochemical performance at the cathode-separator interface result in a high gravimetric capacity of around 670 mAh g−1 at 4C. Unique chemical interactions between fluorine and carbon at the separator and the polysulfides, studied using DFT calculations, establish a new direction of utilizing highly electronegative fluorine moieties and absorption-based porous carbons for mitigation of polysulfide shuttle in Li-S batteries.

The leather industry generates approximately ten million tons of solid bio-wastes that can be used to synthesize various multifunctional materials with exciting properties. One such approach involves developing advanced hybrid materials, which is considered one of the key areas but the underdeveloped materials science discipline. This work explored methods to use collagen derived from leather industry bio-wastes to form hybrid films via two different ways: to produce luminescent carbon dots (Cdots) and develop hybrid films. The polymeric collagen was mixed with Cdots and reduced graphene oxide (rGO) to create flexible composite films that exhibit improved thermal, mechanical, electrical, and luminescent properties. The Cdot films displayed enhanced luminescence. The Kubelka-Munk transformation of the diffuse reflectance reveals a massive increase in absorbance in the visible light region with the addition of rGO. Besides, the developed films displayed electrical conductivity and weak ferromagnetic characteristics and showed enhanced biocompatibility. These findings highlight new avenues for converting industrial bio-wastes into useful multifunctional materials in scalable and inexpensive ways, thereby diminishing environmental pollution and enhancing environmental sustainability.

Synthesis of ultrathin heterostructures has received much attention in the recent past due to their unique physical and chemical properties. In this work, we report the synthesis of Fe2TiO5–TiO2 heterostructures using a simple hydrothermal technique employing natural ilmenite as the source. Hierarchically arranged nanostructures with interconnected nano-petals of thickness around 50 ​nm are obtained. The electrocatalytic properties of the synthesized Fe2TiO5–TiO2 heterostructures are enhanced following the cathodization technique. The observed enhancement in the synthesized materials’ electrocatalytic property can be attributed to the defect-rich Fe2-xTiO5-x-TiO2-x heterostructures. The current approach and technique discussed in this work offer a simple method to synthesize a nanostructured heterostructure material and create defects for enhancing electrocatalytic activity.

Summary: Cementitious structures exhibit high compression strength but suffer from inherent brittleness. Conversely, nature creates structures using mostly brittle phases that overcome the strength-toughness trade-off, mainly through internalized packaging of brittle phases with soft organic binders. Here, we develop complex architectures of cementitious materials using an inverse replica approach where a soft polymer phase emerges as an external conformal coating. Architected polymer templates are printed, cement pastes are molded into these templates, and cementitious structures with thin polymer surface coating are achieved after the solubilization of sacrificial templates. These polymer-coated architected cementitious structures display unusual mechanical behavior with considerably higher toughness compared to conventional non-porous structures. They resist catastrophic failure through delayed damage propagation. Most interestingly, the architected structures show significant deformation recovery after releasing quasi-static loading, atypical in conventional cementitious structures. This approach allows a simple strategy to build more deformation resilient cementitious structures than their traditional counterparts.

A simple yet innovative approach has been made through a powder metallurgy route for the synthesis of aluminum–graphene (Al–Gr) composite materials for commercially viable solar thermal collectors. The Al–Gr composite (with 1 wt. % of graphene filler content) recorded an enhanced thermal conductivity of ∼280 W/mK, which is higher than that of pristine Al (∼124 W/mK), at room temperature. It has also been found that the prepared composite has a lower coefficient of thermal expansion. The structures and morphologies of the composites have been investigated in detail with the help of X-ray diffraction technique, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, etc. Furthermore, the density measurements showed that the composites retain ∼97.5% of the density of pristine aluminum even after the sintering treatment. X-ray micro-computed tomography revealed the structural integrity and non-porous nature of the samples, free from any defects and deformations. The thermal fusing of Al-based composite materials at 630 °C is found to be satisfactory with the required strength, and the composites showed at least ∼125% increase in the thermal conductivity than that of pristine Al. These results suggest that the Al–Gr composites can be deployed as solar thermal collectors and heat sink materials for thermal dissipation.

The investigation into the dynamical transitions of charged quasiparticles on interfaces remains technically challenging. Here, the authors use ultrafast, mid-infrared micro-spectroscopy to unveil the formation of tightly bound interlayer excitons between conducting graphene and semiconducting MoSe2.

Solution-processed two-dimensional perovskite quantum-well-based optoelectronic devices have attracted great research interest but their electrical transport is poorly understood. Tsai et al. reveal that the potential barriers of the quantum wells dominate the transport properties in solar cell devices.

Abstract Adsorption of gas molecules on the surface of atomically layered two-dimensional (2D) materials, including graphene and transition metal dichalcogenides, can significantly affect their electrical and optical properties. Therefore, a microscopic and quantitative understanding of the mechanism and dynamics of molecular adsorption and desorption has to be achieved in order to advance device applications based on these materials. However, recent theoretical calculations have yielded contradictory results, particularly on the magnitude of the adsorption energy. Here, we have experimentally determined the adsorption energy of oxygen molecules on graphene and 2D tungsten disulfide using temperature-programmed terahertz (THz) emission microscopy (TPTEM). The temperature dependence of THz emission from InP surfaces covered with 2D materials reflects the change in oxygen concentration due to thermal desorption, which we used to estimate the adsorption energy of oxygen molecules on graphene (~0.15 eV) and tungsten disulphide (~0.24 eV). Furthermore, we used TPTEM to visualize relative changes in the spatial distribution of oxygen molecules on monolayer graphene during adsorption and desorption. Our results provide much insight into the mechanism of molecular adsorption on the surface of 2D materials, while introducing TPTEM as a novel and powerful tool for molecular surface science.

Electroreduction of CO2 into C2 hydrocarbons and liquid fuels is a promising but challenging energy conversion technology, with copper exhibiting fair selectivity for these products. Here, the authors report that N-doped graphene quantum dots can also catalyze the electrochemical reduction of CO2into multi-carbon hydrocarbons and oxygenates.

Van der Waals heterostructures, fabricated via vertical stacking of two-dimensional materials, hold promise for opto-electronic applications. Here, the authors study the exciton-assisted charge transfer mechanisms occurring in a WS2/MoS2heterojunction via ultrafast microspectroscopy.

Two dimensional materials are promising for electronic applications, which await the exploration of cooperative phenomena. Here, Liu et al. report switchable ferroelectric polarization in thin CuInP2S6film at room temperature, demonstrating good memory behaviour with on/off ratio of ∼100 based on two-dimensional ferroelectricity.

The original version of this Article omitted an affiliation of Xiewen Wen: ‘College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China’. This has been corrected in both the PDF and HTML versions of the Article.

Two dimensional transition metal dichalcogenides (2D TMDs) offer promise as opto-electronic materials due to their direct band gap and reasonably good mobility values. However, most metals form high resistance contacts on semiconducting TMDs such as MoS2. The large contact resistance limits the performance of devices. Unlike bulk materials, low contact resistance cannot be stably achieved in 2D materials by doping. Here we build on our previous work in which we demonstrated that it is possible to achieve low contact resistance electrodes by phase transformation. We show that similar to the previously demonstrated mechanically exfoliated samples, it is possible to decrease the contact resistance and enhance the FET performance by locally inducing and patterning the metallic 1T phase of MoS2 on chemically vapor deposited material. The device properties are substantially improved with 1T phase source/drain electrodes.