Water gas shift (WGS) reaction is crucial for removing CO impurity in industrial hydrogen production. Noble-metal-free Co-based species mainly serve as a support rather than dominant sites for this reaction. Here, a bulk Co4N nanospheres (Co4N-NS) catalyst is prepared via temperature programmed nitriding using Co3O4 nanosphere precursor for low-temperature WGS reaction. It is found that the CO conversion can achieve 97.6% at 240 degrees C, and the thermodynamic equilibrium conversion is reached at 250 degrees C, which is unprecedentedly reported for Co-based catalysts. Moreover, the reaction rate reaches 19.84 mmolCO gcat -1 h-1 with a better stability, 4.5 times higher than that on Co4N-C from commercial Co3O4 precursor. The characterizations and kinetic studies show that Co4N-NS enhances the H2O activation and promotes the CO adsorption, which renders a lower activation energy compared to Co4N-C for the WGS reaction. This study offers insights for designing cost-effective WGS catalysts with transition metal nitrides.

A major challenge in biofilm-associated infection therapy is overcoming biofilm barriers while eradicating embedded bacteria without inducing antibiotic resistance. Here, we report an antibiotic-free microbotic platform that synergistically integrates magnetomechanical biofilm disruption with localized nanozyme-mediated bactericidal activity, enabling efficient and biocompatible biofilm eradication in vivo. Under a rotating magnetic field, nanozyme microbots transition from individual spinning to reconfigurable vortex swarming, generating strong local fluid shear forces that mechanically disrupt the extracellular polymeric substance matrix and drive deep penetration into biofilms. Within the disrupted biofilm, the Fe3O4 nanozyme cores catalyze endogenous H2O2 to produce bactericidal hydroxyl radicals, resulting in effective elimination of both Gram-positive and Gram-negative bacteria. In murine biofilm infection models, the nanozyme microbots significantly reduce the bacterial burden, accelerate wound closure, suppress inflammation, and promote angiogenesis. This work establishes a mechanochemical microbotic strategy that combines programmable swarm dynamics with nanozyme catalysis, providing a promising antibiotic-independent approach to treating chronic biofilm-associated infections.

Addressing the dual challenges of limited gold resources and increasing environmental pollution, the sustainable recovery and functional upcycling of gold from electronic waste (e-waste) has emerged as a promising strategy. Herein, we report an upcycled gold/graphene monolithic scaffold for the electrocatalytic removal of mercapto pollutants using a recovery-utilization strategy. Reduced graphene oxide (rGO) acts as a conductive scaffold that selectively and near-completely captures gold ions through a reductive adsorption mechanism, forming in situ dispersed metallic gold on its surface. The obtained Au-rGO directly functions as an efficient electrocatalyst for mercapto pollutant degradation, achieving removal efficiencies of 96.07%, 85.81%, and 82.47% for 2-mercaptobenzimidazole, sodium thiophenolate and 2-naphthalenethiol, respectively. Mechanistic study reveals a gold-thiol affinity-driven, adsorption-mediated electrocatalytic degradation pathway, where mercapto pollutants undergo successive adsorption on gold surface, Au-S bond cleavage and indirect oxidative degradation by reactive oxygen species, leading to efficient degradation and mineralization of the mercapto pollutants. We further demonstrate Au-rGO catalyst prepared from practical e-waste, the upcycled catalyst exhibits similar high degradation performance to these pollutants. This work establishes an efficient route for coupling gold recovery with direct catalytic upcycling toward sustainable urban mining and efficient wastewater treatment.

Site isolation is an effective strategy for achieving high selectivity for acetylene semihydrogenation, yet often at the cost of reduced activity. Moreover, most of the site isolation approaches involve single-atom catalysts (SACs), less is known about the active site ensemble that can behave even superior to SACs in both activity and selectivity. Herein, by decoration of partially reduced GaOx on the Pd particles in Pd/Al2O3 and followed by in situ treatment in reaction gas, we are able to construct isolated Pd3 sites and identify the structure by using in situ CO-DRIFTS and DFT calculations. Reaction tests for acetylene semihydrogenation under simulated industrial feed gas conditions show that the isolated Pd3 sites offer ∼99% ethylene selectivity at acetylene conversion of 95% at very mild reaction conditions (50 °C and 1 bar), with a turnover frequency of 13.5-fold that of Pd2Ga intermetallic compound, outperforming most of the state-of-the-art Pd-based catalysts. The combined TPD experiments and theoretical calculations reveal that the partially reduced GaOx on the Pd surface not only isolates and stabilizes the Pd3 geometry but also alters the electronic properties of Pd via electron transfer from Ga to Pd atoms, thereby enhancing acetylene adsorption while weakening ethylene adsorption, leading to greatly increased activity and selectivity. This work opens up a distinct avenue from the prevalent SAC strategy toward site-isolation, highlighting the great potential of manipulating the active site ensemble in overcoming the activity-selectivity trade-off in selective hydrogenation reactions.

Precise control of the interlayer spacing of graphene oxide (GO) membranes at the sub-nanometer scale offers size-exclusion-based separation of Li+/Mg2+, a critical step towards efficient lithium resource management and energy sustainability. While previous GO-based membranes have shown high Mg2+ rejections, their performance was largely limited to static diffusion settings or diluted solutions where Donnan exclusion dominates. Here, we report a GO membrane intercalated with a uniform polyelectrolyte layer. The membrane shows substantially enhanced MgCl2 rejection over a wide concentration range, while allowing LiCl permeation under pressure-driven filtration. This enables direct lithium recovery from low-quality brines with high MgCl2 concentrations and high Mg2+/Li+ ratios. Mechanistic study reveals that the adsorption of halide counter-ions onto the charged GO channel walls narrowed the interlayer spacing and enabled size-exclusion-based ionic separation. At higher ionic concentrations, a partial exchange of these adsorbed counter-ions with those in the second hydration shell of Mg2+ allowed moderate Mg2+ permeation. We further demonstrate a streamlined GO-based membrane filtration process, which rejects 99.53% Mg2+ from a low-quality brine, effectively upgrading it towards a high-quality lithium source, and highlighting the potential of this approach for sustainable lithium production.

Water gas shift (WGS) reaction is crucial for removing CO impurity in industrial hydrogen production. Noble‐metal‐free Co‐based species mainly serve as a support rather than dominant sites for this reaction. Here, a bulk Co 4 N nanospheres (Co 4 N‐NS) catalyst is prepared via temperature programmed nitriding using Co 3 O 4 nanosphere precursor for low‐temperature WGS reaction. It is found that the CO conversion can achieve 97.6% at 240°C, and the thermodynamic equilibrium conversion is reached at 250°C, which is unprecedentedly reported for Co‐based catalysts. Moreover, the reaction rate reaches 19.84 mmol CO g cat −1 h −1 with a better stability, 4.5 times higher than that on Co 4 N‐C from commercial Co 3 O 4 precursor. The characterizations and kinetic studies show that Co 4 N‐NS enhances the H 2 O activation and promotes the CO adsorption, which renders a lower activation energy compared to Co 4 N‐C for the WGS reaction. This study offers insights for designing cost‐effective WGS catalysts with transition metal nitrides.

Artificial stimulus-responsive membranes, particularly those responsive to different solvents, have important applications in complex and graded separation systems. Inspired by natural lipid membrane that alters mass transport behavior in response to interactions with various solvents, we report that incorporating porous graphene (PG) into graphene oxide (GO) membrane enables smart and switchable molecular sieving reversibly responsive to solvent types. The membrane shows high permeance for water and methanol, 45.52 and 13.56 L m-2 h-1 bar-1, respectively, and its molecular weight cut-off (MWCO) at ~319 g mol-1 in water, similar to pristine GO membrane, reversibly switches to 960 g mol-1 in methanol which is not observed in either pristine GO or graphene membrane. We accounted this switching to the change of transport pathways. In water, the GO-GO nanochannel is dominant, providing similar molecular sieving to pristine GO. In methanol, the GO-PG nanochannel becomes favorable because a strong solvent adsorption on the nanochannel surface, coupled with a weak solvent network under nanoconfinement, promotes a significant interlayer expansion, reducing the transport resistance and enabling larger, switched MWCO. This switchable sieving behavior is further demonstrated for efficient graded separation of ternary solution of solutes with various molecular weights.

Graphene oxide (GO) is recognized as an important functional material in its own right, with applications ranging from advanced separation to electronics. Previous research has focused on the development of novel fabrication processes, however, precise control over the atomic structure of GO, critical for determining its properties, remains elusive. A cascading oxidation process, enabling stepwise oxidation for control over two key atomic structures–graphitic and oxidized regions–within GO, is reported. By transitioning the conventional diffusion‐controlled kinetics to reaction‐controlled ones, this approach uses a very low oxidant‐to‐graphite ratio ( R = 0.5) and yields low‐oxidation graphene oxide (LoxGO) comprising 41.8% graphitic regions, 58.2% oxidized regions, with negligible hole defects (<0.1% holes). This unique structure also features significantly larger graphitic domains (≈8.3 nm 2 ) compared to typical GO (≈1.3 nm 2 ), resulting in high adsorption capacity and up to ≈2.1 times higher removal efficiency for aromatic emerging contaminants, including endocrine disruptors and antibiotics. Mechanistic studies reveal that efficient bonding to aromatic molecules is attributed to LoxGO's abundant π – π interaction sites, coupled with its large graphitic areas facilitating size‐matching adsorption. These results provide a novel strategy for tailoring GO's atomic structure and offer insights into its molecular interactions to target contaminants, addressing global environmental sustainability.

Pristine two-dimensional (2D) materials have a multitude of interesting properties, promising a broad spectrum of applications. However, their poor affinity for common solvents and tendency to aggregate impede their effective exfoliation and solution-processing into various structures, such as fibers and membranes, thus limiting their practical use. We report a high-efficiency method for producing pristine 2D nanosheets by direct high-speed shearing exfoliation in trifluoromethanesulfonic acid (TfOH). Typically, this method produces hexagonal boron nitride nanosheets (BNNSs) with an unprecedented throughput of 38.8 mg mL-1h-1. The effective exfoliation is attributed to the strong binding affinity, large dipole moment and steric repulsion of TfOH, which collectively introduce layer edge distortion in hexagonal boron nitride (hBN), facilitating its exfoliation. The mechanical exfoliation and reversible edge interaction introduce no additional functional groups to the exfoliated BNNSs. The resulting pristine BNNS exhibit remarkable stability in TfOH solutions at ultrahigh concentrations of 200 mg mL-1 for over 28 days. The viscosity of the highly concentrated BNNS/TfOH dispersion can be adjusted, enabling techniques to produce BNNS-based spheres, fibers, and membranes with high thermal conductivity and mechanical strength, suitable for advanced thermal management applications. Room temperature processed BNNS-based spheres exhibit superior thermal conductivity compared to high temperature processed commercially available hBN or Al2O3 spheres. Moreover, TfOH can also be used to assist the efficient production and solution-processing of other 2D nanosheets, including graphene, molybdenum disulfide and tungsten disulfide, enabling the fabrication of high-quality bulk assemblies.

Graphene's ultrahigh in-plane thermal conductivity makes it an ideal material for thermally conductive films in various electronic applications. However, the inherently weak interlayer interaction in conventional graphite films (GrF) results in low through-plane thermal conductivity. Here, we firstly developed a novel structure of opened micro-window arrays in the graphite film (MW-GrF) to significantly enhance the through-plane thermal conductivity by the laser-etching-assisted and micro-origami methods. The opened micro-window arrays are acted as bridges to promote interfacial thermal transport via utilizing the ultrahigh in-plane thermal conductivity of micro-windows, which can achieve a reduction of ∼ 60 % in through-plane thermal resistance, with the lowest value of 0.286 K cm2 W-1. Meanwhile, the through-plane thermal conductivity of MW-GrF was greatly improved to 82.4-89.6 W m-1 K-1 compared to the original GrF with 4.4-6.9 W m-1 K-1. This work provides a simple, scalable and programmable method for finely tailoring the through-plane thermal properties of graphene films, making them promising candidates for highly efficient heat dissipation in future high-power chips.

The intensive and irreplaceable consumption of precious metals (PMs) including gold (Au), palladium (Pd) and platinum (Pt) in the electronic and catalysis industries, coupled with their scarcity in Earth's crust, demand innovative recycling solutions for PM sustainability. However, efforts to recycle PMs from leachates of their waste are frustrated by an unsatisfactory extraction capacity at low concentrations and remain predominantly focused on gold, leaving other PMs largely unexplored. We report the ultrahigh reductive recycling of PM ions and their simultaneous aqueous-phase deposition on semimetallic transition-metal dichalcogenides of TiS2 and TaS2 nanosheets. Notably, TiS2 shows unprecedentedly high extraction capacities of ∼8, 2.3 and 1.15 g/g for Au, Pd and Pt ions, respectively, and the adsorbed PM ions are directly transformed into nanoparticles deposited on the nanosheets. Mechanistic studies reveal that water-mediated electron donation from the sulfur site of the semimetallic TiS2 and TaS2 nanosheets is responsible for the ultrahigh extraction capacity, with a single TiS2 molecule donating >13 electrons to gold ions. This electron transfer is mediated by the formation of sulfur-oxygen species during water dissociation. We further demonstrate the selective and complete recovery of Au, Pd and Pt from real-world waste streams including electronic waste, spent catalysts and automotive catalytic converters.

The sustainable utilization of precious metal (PM) resources holds critical significance for electronics, catalysis, and related industries, driving the urgent need to develop efficient and eco-friendly PM recovery technologies. In a PM recovery process, an adsorbent material that can efficiently and selectively recover PM from its complex co-existing metals is critical for process efficiency. Currently, the commonly used precious metal adsorbent is activated carbon; its hierarchical pore structure provides a large specific surface area and spatial confinement, beneficial for efficient adsorption. However, such pore structure poses inter-pore diffusion, resulting in slow adsorption kinetics. Additionally, most activated carbon-based adsorbents rely on physisorption, lack the selectivity needed for complex matrices seen in PM recovery, and only result in a moderate adsorption capacity. In contrast, 2D materials, such as graphene, have emerged as promising adsorbents for PM recovery. Its planar structure exposes all of its volume as surfaces, which provides a large surface area desired for efficient adsorption; however, a lack of intrinsic pore structure also implies little spatial confinement for the adsorbates, which is likely to cause desorption, unfavorable for high adsorption capacity. Therefore, tailoring the surface of 2D materials to establish strong interactions with target adsorbates is a critical step for achieving efficient PM adsorption. This review systematically analyzes the adsorption mechanisms of graphene-based and other graphene-like 2D materials, including transition metal dichalcogenides (TMDs) and MXenes, focusing on how surface chemistry and structural features dictate metal ion binding, with reductive adsorption as a dominant mechanism. It evaluates recent advancements in applying these materials to recover PMs from e-waste, industrial effluents, and seawater. Specifically, graphene oxide (GO) achieves capacities like 108.34 mg/g for Au3+, while reduced graphene oxide (rGO) reaches 1850 mg/g with rapid kinetics; rGO/chitosan reaches 16800 mg/g. TMDs and MXenes achieve efficient adsorption of gold and PMs beyond gold, including platinum and palladium, through light-induced reduction and surface defect-induced deposition. The review particularly evaluates graphene-based adsorbents, highlighting their electron-rich structures and tunable surfaces that enhance selectivity and capacity over activated carbon, alongside practical integrations like rGO membranes for continuous gold recovery, supporting a closed-loop economy and sustainable resource management. The review also discusses challenges in using 2D materials for PM recovery, including co-existing ion interference, high synthesis costs, and scalability. Furthermore, the review suggests the need for further research into improving kinetics and selectivity, proposing directions such as functionalization of 2D materials for improved adsorption selectivity and capacity, cost-effective and scalable synthesis, and their integration into practical recycling processes (e.g., seawater desalination-coupled recovery). These advancements highlight 2D materials' potential as an efficient adsorbent material, which was overlooked previously, and suggest their novel application in addressing PM resource scarcity and environmental sustainability.

ABSTRACT The increasing accumulation of e‐waste containing precious metals calls for the development of efficient recycling strategies for gold recovery from e‐waste. In this study, we present scalable fabrication (up to 3600 cm2) of rGO/cellulose composite papers with a high rGO areal density of 7.5 g/m2 and their use as efficient and large‐area adsorbents for gold extraction. The resulting rGO@cellulose composite exhibits excellent gold extraction capacity, achieving 20 and 36.3 g/m2 at 25°C and 60°C, respectively, which translates to high gravimetric capacities of 2662 mg/g and 4833 mg/g. When used for gold extraction from e‐waste containing 13 types of metals, the rGO@cellulose maintains a precise selectivity for gold and achieves high extraction efficiency of 99.6%, providing a promising avenue for the sustainable recovery of gold from e‐waste. Furthermore, the gold recycled by the rGO@cellulose can be reused for photothermal steam generation and catalytic degradation of environmental contaminants, demonstrating its potential for diverse environmental applications beyond gold extraction. This work provides a sustainable approach to e‐waste recycling, offering a pathway to address environmental challenges while promoting the circular use of resources.

The excellent impermeability makes graphene film an ideal candidate for thin film encapsulation technology. However, current chemical vapor deposition (CVD) graphene-based barrier films can not provide sufficient moisture barrier performance, suggesting a lack of understanding in mechanism that dominates water diffusion in/through graphene stacks. Herein, we fabricate large-area graphene barrier films with a record-low water vapor transmission rate (WVTR) of 5 × 10-5 g/(m2·day), two orders of magnitude lower than previous works, in which two stacked Janus graphene films are intercalated by toluidine blue O (TBO) sub-monolayer: one side of graphene is decorated with fluorine- and oxygen-containing groups to allow crack-free transfer, while the other side is functionalized with hydroxyl groups to trap water. The intercalated TBO further blocks water transport due to a strong water-TBO interaction. Our work opens a route for surface/interface engineering of CVD graphene and promises its exciting future in the applications for advanced packaging.

The rapid evolution of fifth-generation (5G) communication technology calls for next-generation packaging materials that not only excel in dielectric performance like dielectric constant and dielectric loss but push the demand for thermal stability. Here, we explore superhydrophobic fluorinated graphene (FG), revealing a remarkable combination of dielectric properties and thermal stability that make FG a standout candidate for electronic packaging in 5G applications. By fine-tuning the fluorine-to-carbon (F/C) ratio in the FG, we have achieved a dielectric constant as low as 1.50 with an F/C ratio of 1.18, significantly lower than many conventional materials. Even more impressively, our FG exhibits an ultra-low dielectric loss of just 0.0037 at 10 MHz. Beyond its outstanding electrical performance, FG boasts exceptional thermal stability, with a decomposition temperature high to similar to 500 degrees C, far surpassing standard polymers for packaging materials. Moreover, its hydrophobic nature remains stable in outdoor environments, cementing its reliability over time. With its low dielectric constant, minimal dielectric loss, high thermal resilience, and environmental durability, FG holds tremendous promise as a competitive candidate in advanced packaging materials for 5G technology.

The environmental occurrence of anthropogenic chemicals—especially persistent micropollutants of perand polyfluoroalkyl substances(PFAS)—raises pressing concerns for global drinking-water safety.Adsorption is an effective technology for removing PFAS but is limited by unsatisfactory adsorption capacity and efficiency.We report a strategy to attach polyamine adlayers to graphene oxide(GO)nanosheets that produces highly charged and monodispersed 2D adsorbents of a GO nanosheet sandwiched between two 1-nm-thick polyamine adlayers.This adsorbent has a high adsorption capacity for PFAS of ～3070 mg/g—tens of times greater than that of GO and commercial activated carbon.It also provides almost instant adsorption of a variety of PFAS and reaches 57%-95% of its equilibrium capacity in a minute and removes ～100% of PFAS from contaminated water sources within a few minutes.transforming real-life PFAS-contaminated water into safe drinking water.Experiment and theory show that the planar nature of the 2D adsorbent combined with its abundant surface adsorption sites that electrostatically attract the polar groups of the PFAS,and hydrogen bonding and hydrophobic-hydrophobic interactions with their non-polar groups,account for its ultra-high adsorption capacity and rapid removal efficiency.We also show that regeneration of the adsorbents removes the adsorbed PFAS and allows subsequent destruction,demonstrating a closed-loop treatment solution for micropollutant contamination.

Gene therapy has been extensively investigated and widely used in biomedical fields, such as cancer treatment. However, the most important issues for gene therapy are stability, targeting effect, transfection efficacy, and safety of gene formulation after administration, which seriously limit the further application of gene therapy in clinic. Therefore, gene delivery could be a promising strategy for overcoming these challenges. Two-dimensional (2D) materials are rising nanomaterials with excellent physical and chemical properties, including large specific surface area, easy modification, high conversion efficiency of light, and good biocompatibility, which have achieved promising applications as vehicles for gene delivery in the disease treatment. In this review, we first summarized the research progress of 2D material-based nanosystems for gene delivery to improve the therapeutic efficacy. We discussed that 2D material-based gene delivery nanosystems showed high therapeutic efficacy for many diseases treatment, especially cancer. Furthermore, we also proposed that surface modification of 2D materials might be a promising strategy to prepare multi-functional gene carriers for combination therapy with enhanced treatment efficacy. Finally, the future research progress, challenges, and prospects of 2D material-based nanosystems for gene therapy were discussed and concluded. Conclusively, we believe that 2D material-based nanosystems with good biocompatibility and high transfection efficiency would be potentially used in clinical settings to improve the therapeutic efficacy of gene therapy.

The conventional fabrication of bulk van der Waals (vdW) materials requires a temperature above 1,000 °C to sinter from the corresponding particulates. Here we report the near-room-temperature densification (for example, ∼45 °C for 10 min) of two-dimensional nanosheets to form strong bulk materials with a porosity of <0.1%, which are mechanically stronger than the conventionally made ones. The mechanistic study shows that the water-mediated activation of van der Waals interactions accounts for the strong and dense bulk materials. Initially, water adsorbed on two-dimensional nanosheets lubricates and promotes alignment. The subsequent extrusion closes the gaps between the aligned nanosheets and densifies them into strong bulk materials. Water extrusion also generates stresses that increase with moulding temperature, and too high a temperature causes intersheet misalignment; therefore, a near-room-temperature moulding process is favoured. This technique provides an energy-efficient alternative to design a wide range of dense bulk van der Waals materials with tailored compositions and properties.

A solar steam evaporator provides a sustainable and efficient alternative water purification solution to address the global freshwater shortage. Previous efforts have made significant advances in maximizing its water evaporation rate, but no single evaporator has all the properties necessary for practical point-of-use application, including a high efficiency for generation of drinkable water, an excellent portability critical for on-site water purification, good washability for mitigating evaporator fouling, and good reusability. We report a strategy to produce a high-performance photothermal material for point-of-use water purification. By simultaneously incorporating graphene and gold particles grown from recycled electronic waste in a mechanically strong sponge, we achieved highly efficient water purification under realistic conditions. In addition to a high evaporation rate (3.55 kg/m2/h under one-sun irradiation) attributed to a control of atomic structure of graphene and the size-dependent surface plasmon resonance of gold nanoparticles, it is portable which can be folded, vacuum compacted, dried and rehydrated without compromising performance. It also allows repeated washing to remove contaminant fouling so that it can be reused. The evaporator transforms various types of contaminated water into drinkable clean water, and can be mounted at any angle to optimize the incident solar irradiation. Furthermore, the assembled steam evaporator device could gain purified water meeting the World Health Organization drinking water standards with a high evaporation rate of 9.36 kg/m2/h under outdoor sunlight.

Autocatalysis has been recognized to be involved in the emergence of life and intrinsic to biomolecular replication. Recently, an efficient template autocatalysis driven by solvent-free crystallization has been reported. Herein, we unveil the role of intermolecular hydrogen bonds formed by amides in crystallization-driven template autocatalysis (CDTA), which involves the autocatalytic activity, template selectivity, and thermal responsiveness. We found that the thermal-induced cis-trans isomerization of amides possibly affects the H-bonding-mediated template ability of products for autocatalytic transformation. As a result, CDTA can be reversibly inhibited and activated by tuning the reaction temperatures. Our work sheds light on the significance of noncovalent H-bonding interactions in artificial self-replicators.