3D Graphene Materials: From Understanding to Design and Synthesis Control

All-in-one design of titanium-based dental implant systems for enhanced soft and hard tissue integration

Enhancing the sealing between titanium abutment and surrounding soft tissue is crucial for preventing peri-implantitis. Meanwhile, exploring non-invasive antibacterial strategies as alternatives for traditional antibiotic therapy is central to improving the effect of peri-implantitis treatment. Furthermore, facilitating effective integration between titanium implant and osteoporotic bone is the cornerstone for ensuring long-term implant stability in patients with osteoporosis. In light of this, this work innovatively constructed multifunctional vertical graphene-based coatings on titanium implants and abutments using plasma-enhanced chemical vapor deposition technology. The results demonstrated that the vertical graphene coatings promoted soft tissue sealing and exhibited inherent antibacterial activities with the bacteriostasis rates of 65.60 % against Staphylococcus aureus (S. aureus) and 43.89 % against Escherichia coli (E. coli) in vitro which could prevent early infections. Moreover, vertical graphene coatings presented photothermal antibacterial effects with the antibacterial rates of 99.99 % and 95.83 % for S. aureus in vitro and in vivo, respectively, and 92.23 % for E. coli in vitro under near-infrared irradiation, which provided a non-invasive and highly effective treatment option for peri-implantitis. Furthermore, teriparatide acetate was loaded on vertical graphene coatings which enhanced osseointegration between titanium implants and osteoporotic bone. By comprehensively considering the critical functional requirements of dental implants and abutments, this work meticulously designed vertical graphene-based coatings on titanium dental implant systems for soft and hard tissue integration. This innovative design demonstrates immense application potential, especially for dental implant restoration in patients with osteoporosis.

Progress of 0D Biomass-Derived Porous Carbon Materials Produced by Hydrothermal Assisted Synthesis for Advanced Supercapacitors

Supercapacitors are garnering considerable interest owing to their high-power density, rapid charge-discharge capability, and long cycle life. Among the various materials explored, biomass-derived carbon nanomaterials stands out as a sustainable and cost-effective choice, thanks to its natural abundance and eco-friendly characteristics. This review delineates recent advances in the synthesis of zero-dimensional (0D) carbon nanomateirlas from various biomass precursors via hydrothermal assisted synthesis. It offers a comprehensive discussion on the factors affecting the synthesis of 0D carbon nanomaterials, including precursor type, concentration, reaction temperature, and time. Furthermore, the review underscores the impact of different activation methods on the morphology and electrochemical performance of 0D carbon nanomaterials. Finally, we outline the challenges and future prospects of utilizing biomass-derived carbon nanomaterials in supercapacitor applications, emphasizing the importance of optimizing synthesis parameters to attain the desired material properties.

Synthesis and Evaluation of 3D Nitrogen Doped Reduced Graphene Oxide (3D N@rGO) Macrostructure for Boosted Solar Driven Interfacial Desalination of Saline Water

Recently, there has been a growing interest in solar-driven interfacial desalination technology, which focuses on the localization of heat to the air-water interface. In this study, 3D nitrogen-doped reduced graphene oxide (3D N@rGO) photothermal material is synthesized with a facile one-step hydrothermal process. The material exhibited richer porosity, high hydrophilicity for efficient water channeling, and all-directional solar absorption potential. The 3D N@rGO solar absorber attained up to ≈55 °C surface temperature rise and showed ≈134% photothermal conversion efficiency with 1.94 kg m-2 h-1 net freshwater generation rate under 1 sun solar illumination, owing to efficient latent heat recycle. On a high salinity desalination study performed using 10 and 20 wt.% salinity levels, the photothermal material showed 1.66 and 1.31 kg m-2 h-1 evaporation rates respectively. It sustained stable long-term desalination performance without visible salt accumulation on the surface up to a salinity level of 10 wt.%. In a three-day outdoor test carried out utilizing simulated seawater with a 3.5 wt.% NaCl solution, the 3D evaporator demonstrated an average freshwater production rate of 2.61 kg m-2 h-1, during the test the solar power density reached up to 1.1 kW m-2. The 3D solar absorber exhibited a promising potential for large-scale seawater desalination in water-scarce regions worldwide.

Integration of Carbon Nanotubes into Manganese Dioxide Nanorods for Enhanced Enzymeless Electrochemical Glucose Sensing with High Sensitivity and Selectivity

Freestanding electrode designs, cost-effective catalysts, and enhanced electrical conductivity are crucial for improving the performance of fourth-generation non-enzymatic glucose electrochemical sensors. These factors enable more efficient, scalable, and durable sensors with better sensitivity, stability, and affordability for real-time glucose monitoring. In this study, we explore a freestanding electrode design combining carbon nanotubes (CNTs) with MnO2 nanorods to enhance charge transfer, increase surface area, and optimize catalytic activity. This CNTs/MnO2 electrode demonstrates exceptional catalytic activity for glucose oxidation, achieving a high sensitivity of 309.73 µA cm-2 mM-1 within a linear range of 0.5 to 10 mM-well above typical physiological glucose levels (3-8 mM), with a detection limit of 0.19 mM at a signal-to-noise ratio of 3. The electrode also shows excellent durability and remarkable selectivity for glucose over common interferents like ascorbic acid and uric acid, as well as antifouling properties in the presence of KCl. These attributes are essential for accurate glucose detection in complex biological samples. The integration of MnO2 nanorods with CNTs in freestanding nanostructures opens up exciting opportunities for developing high-performance, robust electrochemical sensors for diverse applications.

Femtosecond Laser Opening Hierarchical Lamination: Micro-Nano Hybrid Scissoring of Three-Dimensional Nitrogen-Doped Graphene for Solar Steam Generation

Three-dimensional (3D) nanoporous nitrogen-doped graphene is an ideal candidate for solar steam generation. However, the outermost dense layer formed during high-temperature thermal chemical vapor deposition (CVD) severely blocks water transport and steam escape. In this work, a technique of femtosecond laser opening hierarchical lamination (FLOHL) enabling hierarchical micro-nano hybrid scissoring of graphene is presented for its structural and performance upgrades. FLOHL not only allows noncontact rapidly hierarchical opening of the blocked layer but also enables opening lamination of close thin-wall graphene into suspended sheets, while maintaining a robust connection with the framework facilitating stable repetitive use for water evaporation. After FLOHL, solar absorption, heat localization, and interfacial wetting are all dramatically enhanced, increasing water evaporation rates from 1.58/1.56 to 1.79/1.77 kg m-2 h-1 for two prototypes under 1 sun irradiation and conversion efficiency from ∼80% to ∼90%, making them better than many solar evaporators built with graphene and its derivatives, including laser-induced graphene.

Laser processing materials for photo-to-thermal applications

Photothermal conversion materials (PCMs) are crucial component in solar-thermal energy technologies. Although various PCMs with excellent sunlight harvesting have been developed for colorful solar-thermal applications, uniform and large-scale production of PCMs remains a challenge, and the PCMs prepared through the conventional methods are often non-site specific. Laser processing technology (LPT), as an efficient, convenient, green and sustainable technology, can directly create micro/nano structures and patterns at specific locations on materials surface, attracting widespread attention in photo-to-thermal applications. Here, we summarize the laser processing of preparing PCMs through laser sintering, laser modification, laser ablation in liquid, laser induced carbonization, and laser etching. We also introduce the working mechanism of LPT, and analyze the thermal conductivity, heat storage performance and hydrophilic/hydrophobic properties of the substrate after LPT treatment. Furthermore, the application of LPT in solar anti-icing/deicing, seawater desalination, heat exchange system, energy storage and transfer, and other related fields are introduced. Additionally, we provide a prospect for the development of LPT and offer directions for future research. We hope that this review can provide meaningful reference value for scholars in this field.

One-Step Laser-Guided Fabrication of 3D Self-Assembled Graphene Micro-Rolls

Laser-induced graphene (LIG) has been systematically investigated and employed because of the spartan laser synthesis and functional three dimensional (3D) foam-like structures. However, thermally induced deformation during laser processing is generally undesirable and, therefore, strictly suppressed. This work introduces a novel laser-guided self-assembly approach integrated into the fabrication of LIG to generate multiscale 3D graphene foam structures in a single step. Leveraging the photothermal effects of laser ablation on polyimide films, we achieve concurrent LIG production and self-assembly, enabling the transformation of two dimensional films into 3D micro-rolls. The process is finely tuned through interface modification and optimized laser parameters, allowing precise control over the geometry of the resulting structures. Systematic investigations reveal that varying laser power and line spacing effectively adjust the diameters of the LIG micro-rolls. Characterization indicates that the LIG micro-rolls can be fabricated with very large curvature and limited internal space, enhancing the potential for microscale applications. Furthermore, our laser strategy facilitates the creation of symmetric, asymmetric, and double-tube micro-rolls, underscoring its design flexibility. This work highlights the potential of the laser-guided self-assembly strategy in graphene nanomaterials and miniaturized applications, which has been exemplarily verified through the LIG micro-roll supercapacitors.

Highly efficient visible-light-driven S-scheme graphene bridged MoS2/Co3O4 nanohybrid for the photocatalytic performance of hazardous dye and antibacterial activity

A novel graphene-bridged MoS2/Co3O4 (MCG) nanohybrid was well fabricated by a hydrothermal route. The purpose of valuable and economical S-scheme systems with vigorous interface interactions is pressing to photocatalytic efficiency and efficient utilization. While mighty progress has been created with respect to charge carrier bridges, the charge transferring ability of the facility charge carrier bridges is far from capable owing to lower electrical conductivity. The photocatalytic antibacterial tests were performed with visible light activity, and the results exhibited that the as-prepared MCG nanohybrid with powerful interfacial coupling presented excellent photodegradation performance in comparison with bare MoS2 and Co3O4 samples for the removal of methylene blue (MB) and E-coli with visible light irradiation. In addition, a better photocatalytic MB capability and antibacterial activity of 99.5 % and 100 % are approached through MCG-4 nanohybrid, which is 2.76 and 8.32 folds higher than that of the pristine MoS2 sample. The PL measurements and EIS analysis also illustrated that MCG-4 nanohybrid possesses a great separation efficiency of photoinduced charge carriers. This work provides a new objective for high-potential S-scheme photocatalysts and their utilization in the field of environmental remediation.

Tetramethylguanidine-Modified Graphene Oxide as a Gel Polymer Electrolyte Additive for Improving the Performance of Flexible Zinc-Air Batteries

Flexible zinc-air batteries (FZABs) present a promising solution for the next generation of power sources in wearable electronics, owing to their high energy density, cost-effectiveness, and safety. However, solid-state electrolytes for FZABs continue to face challenges related to rapid water loss and low ionic conductivity. In this study, a hydrophilic and stable tetramethylguanidine-modified graphene oxide as an additive, which is incorporated into sodium polyacrylate to develop a high-performance gel polymer electrolyte (GPE), is designed. The addition of additives makes GPE more hydrophilic, allowing for a wider hydrogen bonding network and more efficient ion transport channels. Due to its stable structure, abundant water channels and fast OH- conductivity, GPE also offers excellent mechanical properties, long-lasting water retention, and high ionic conductivity (173.9 mS cm-1). FZABs assembled with this GPE exhibit a high open-circuit voltage of 1.558 V, a cycle life of 230 h, a specific capacity of 810.3 mAh g-1, and a peak power density of 130.5 mW cm-2, coupled with impressive flexibility. These characteristics underscore their significant potential for applications in wearable electronics.

In Situ Laser Direct Writing of Graphene-Based Layered Hybrid Materials with Superhydrophilicity

Laser-induced graphene (LIG) has attracted extensive attention as an electrode material. However, it usually exhibits limited electrochemical performance in many applications due to the limited electrical conductivity and charge storage properties. Herein, we proposed a simple and environmentally friendly strategy for in situ preparation of flexible Au/LIG/PI layered hybrid materials using laser direct writing. The transformation from hydrophobic to superhydrophilic of hybrid materials was successfully achieved. At a laser power of 6.0 W during laser reirradiation, the contact angle of the prepared Au/LIG/PI layered hybrid material was 0°. Characterizations confirmed a formed continuous Au layer covered on the porous LIG skeleton with a uniform distribution. The superhydrophilicity resulting from this unique microstructure greatly enhanced the electrochemical performance of the microsupercapacitors (MSCs) designed and fabricated based on Au/LIG/PI hybrid materials. Meanwhile, this MSC demonstrated excellent flexibility due to the PI substrate. The in situ preparation of superhydrophilic Au/LIG/PI layered hybrid materials provides a strategy for improving the performance of LIG-based MSCs, thereby enhancing their application potential.

Freeze-Casting Mold-Based Scalable Synthesis of Directional Graphene Aerogels with Long-Range Pore Alignment for Energy Applications

In various applications, the pore structure of a porous medium must be controlled to facilitate heat and mass transfer, which considerably influence the system performance. Freeze-casting is a versatile technique for creating aligned pores; However, because of the complexity of the associated equipment and the energy inefficiency of liquid-nitrogen-based cooling in a room-temperature environment, limits scalability for industrial applications. This study is aimed at establishing a novel freeze-casting strategy with a simple mold design combining heat-conductive and insulating materials for long-range pore alignment via directional ice growth under deep-freezing conditions, rendering it feasible for large-scale production. Using this technique, axially aligned (Axial-GA) is developed, radially aligned (Radial-GA), and randomly distributed (Random-GA) pore structures within NaBr-impregnated graphene aerogel (GA-NaBr) configurations, demonstrating enhanced ammonia adsorption for thermal energy management. The pore structure exerted notable effects on the ammonia adsorption behavior, with Radial-GA exhibiting a higher adsorption rate due to reduced ammonia transit distance. The Radial-GA-NaBr structure demonstrated unique adsorption characteristics, retaining ≈85% of the adsorption capacity and achieving a ≈270% adsorption rate gain compared with pure NaBr powder. Overall, this research demonstrates the fabrication of aerogels with various configurations and orientations using facile and scalable methods, thereby expanding their industrial applications.

FeS-based nanocomposites: A promising approach for sustainable environmental remediation - Focus on adsorption and photocatalysis - A review

Population expansion, industrialization, urban development, and climate changes increased the water crisis in terms of drinking water availability. Among the various nanomaterials for nanoremediation towards water treatment, FeS-based nanocomposites have emerged as promising candidates in the adsorptive and photocatalytic removal of contaminants. This paper, therefore, evaluates the potential of FeS-based nanocomposites for environmental applications, more specifically the combined use of adsorption and photocatalysis. Pyrite and mackinawite structures outcompeted the other FeS configurations due to their large surface areas, numerous active sites, and enhanced conductivity, factors that enhance the adsorption and photovoltaic processes. To improve photocatalytic performance FeS requires modification with additional materials. Various fabrication strategies (including hydrothermal method, co-precipitation, electrochemical anodization, electrospinning, impregnation, green synthesis, mechanochemical approach/ball milling) of FeS-based composites and their efficacy and the mechanisms for removing organic and inorganic pollutants are reviewed in this paper. The structural characteristics of FeS scaffolds play a crucial role in the effective removal of heavy metals, such as Hg and Cr ions, primarily through ion exchange and surface complexation. Organic pollutants such as methylene blue and tetracycline were effectively degraded by advanced oxidation processes (AOPs). A large scale applications of FeS include industrial wastewater treatment, groundwater remediation towards trichloroethylene and other organic solvents removal, municipal wastewater, oil spills cleanup, pre-treatment for seawater desalination. Current challenges relate to catalysts stability, their removal after treatment stage, recycling, metals leaching and up-scaling as well as high effectiveness in real case-scenario and costs optimization. In summary, this review will help to advance research in the field of environmental remediation using FeS-based nanocomposites.

A Biomimetic One‐Stone‐Two‐Birds Hydrogel with Electroconductive, Photothermally Antibacterial and Bioadhesive Properties for Skin Tissue Regeneration and Mechanosensation Restoration

Severe skin wounds arising from burns, cancers, and accidents can damage the entire tissue structure, resulting in permanent somatosensory dysfunction in patients. Although emerging hydrogel dressings have shown clinical potential for accelerating wound repair, the use of an individual material to synchronously restore the tissue structure and sensory function of defective skin remains a challenge. Herein, a multifunctional hydrogel that combines electroconductive polydopamine‐capped graphene nanosheets (PrGOs) embedded in a dynamically crosslinked dual‐polysaccharide (xyloglucan and chitosan) matrix network is presented. The fabricated hydrogels have an adjustable modulus that can be matched to skin tissue at the wound site, owing to the dynamic Schiff‐based crosslinking as well as the facile photo‐triggered secondary crosslinking. Furthermore, the photothermal activity of PrGO can elevate the local temperature up to ≈50 °C, significantly restraining bacterial growth. These two factors jointly promote the regeneration of skin tissue. Tissue adhesion of hydrogels is also reported that offers a conformable and robust interface that can detect and quantify human movement and physiological signals to mimic the human skin somatosensory system. This hydrogel offers an effective one‐stone‐for‐two‐birds material that simultaneously achieves tissue regeneration and multi‐signal sensing, promoting the restoration and/or replacement of the structure and function of damaged skins.

Graphene-Based Material Supports for Ni- and Ru- Catalysts in CO2 Hydrogenation: Ruling out Performances and Impurity Role

Laboratory-prepared Gnp using molten salt, commercial Gnp and reduced graphene oxide (rGO) have been characterized and utilized as support for CO2 hydrogenation catalysts. Ni- and Ru- catalysts supported over Gnp, commercial Gnp and rGO have been deeply characterized at different stages using Raman, IR, XRD, FE-SEM-EDXS, SEM-EDXS, XPS, and TEM, also addressing carbon loss before reaction and evolved species, thus allowing a better comprehension of the produced materials. Ni and Ru/rGO were inactive while Gnp-supported ones were active. Ru has been found almost completely selective toward reverse Water Gas Shift to CO, approaching the forecasted thermodynamic equilibrium at 723 K, in the tested conditions (YCO~55 %), with an apparent activation energy in the range of 70-90 kJ/mol. Exhaust catalysts pointed out the presence of sulfur partially linked to the carbon matrix and partially producing the corresponding metal sulfide with the detection of surface oxidized species in the cationic form and adsorbed species as well. The metal-based nanoparticles displayed a quite narrow size distribution, confirming the promising behavior of these catalytic systems for CO2 utilization.

Theoretical study on the prediction of optical properties and thermal stability of fullerene nanoribbons

In this work, we predicted two different configurations of fullerene nanoribbons (quasi-hexagonal phase (qHP) and quasi-tetragonal phase (qTP)) based on two-dimensional fullerenes, with widths of 1, 2, and 3 fullerene units, respectively. Based on first-principles calculations and ab-initio molecular dynamics (AIMD), the thermal stability and optical properties of six fullerene nanoribbons were predicted. AIMD studies indicate that wider qHP nanoribbons (qHPs) exhibit better thermal stability, while increased temperatures lead to greater instability. In contrast, qHP-3 shows the best thermal stability among the six structures. Then, the optical gap between the calculated and experimental quasi-hexagonal two-dimensional fullerenes is compared to illustrate the accuracy of the calculation. The absorption spectra of six fullerene nanoribbons were calculated and the anisotropy of light absorption was analyzed. Finally, the charge transfer modes of each excited state were visualized through electron-hole density plots. This work provides an essential theoretical foundation for understanding new all-carbon materials, specifically fullerenes.

Upconversion nanoparticles incorporated with three-dimensional graphene composites for electrochemical sensing of baicalin from natural plants

Chinese medicine has been widely studied owing to its many advantages. Baicalin (Bn), extracted from natural plants, has been shown to have significant anti-inflammatory and anticancer activity. Therefore, it is of great significance to develop a suitable method to detect the content of Bn in traditional Chinese medicine. Herein, we report an electrochemical sensor for the sensitive detection of Bn in Scutellaria root samples through a synergistic effect between upconversion nanoparticles (UCNPs) and three-dimensional macroporous graphene (3DG). The prepared UCNP-3DG composite was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction spectroscopy (XRD). This proposed sensor exhibited a low detection limit of 3.8 × 10-8 M (S/N = 3). Importantly, the established method possesses good stability and selectivity and can successfully detect Bn in Scutellaria root samples. It provides a suitable strategy for the determination of Bn and has potential application prospects in the assay of traditional Chinese medicine.

Multi-scale microstructural construction in ultralight graphene aerogels enables super elasticity and unprecedented durability for impact protection materials

Ultralight graphene aerogels have gained extensive recognition in the impact protection field. However, attaining both elasticity and durability at low material density is challenging due to their intrinsic conflicts. Inspired by the mantis ootheca, we present a simultaneous improvement in the elasticity, durability, and density restrictions of ultralight graphene aerogels via constructing a multiscale honeycomb microstructure (MHM) within the graphene skeleton. This approach enables resulting graphene aerogel to achieve a strength per unit volume of 284.6 cm3 mg-1, the ability to recover its shape within 10 ms after an impact at 3.569 m/s, and maintain 97.2 % of its sample height after 20,000 cycles at 90 % strain. The operand analyses and calculation results reveal that the MHM structure facilitates this aerogel's dual-stage stress transfer pathway. Initially, the macroscale honeycomb structure (millimeter-scale) of the graphene aerogels bear and transmit stress to the surrounding regions, followed by the microscale honeycomb structure (micron-scale) deformation to convert stress kinetic energy into elastic potential energy. This two-stage stress transition mechanism of the MHM structure can effectively mitigate excessive local stress and suppress strain localization, thus providing remarkable elasticity and durability. Ultimately, the obtained graphene aerogel demonstrates promising applications as a fall height detection device and impact protective material.

van der Waals-bonded graphene clusters enhance thermal conductivity of phase-change materials for advanced thermal energy management

Organic phase-change materials possess immense application potential, but their low thermal conductivity (≤0.5 W m-1 K-1) severely limits the thermal energy charge/discharge rate, impeding their practical implementation in the field of advanced energy. While incorporating thermally conductive fillers into the phase-change matrix can address this issue, achieving a thermal conductivity exceeding 10 W m-1 K-1 at a filler content below 30 vol% remains challenging, attributed to the absence of a well-designed filler interface and structure. Herein, a strategy for developing planar graphene clusters and subsequently integrating them with phase-change microcapsules to fabricate composites using compression molding was demonstrated. The proposed graphene clusters are formed by closely aligned and overlapping graphene sheets that bond together through van der Waals forces, resulting in a significant decrease in junction thermal resistance within the composites. Combining this interface design with compression-induced construction of a highly oriented structure, the composites achieved a remarkable thermal conductivity of 103 W m-1 K-1 with ≈29 vol% filler addition, enhancing the thermal energy charge/discharge rate by over two orders of magnitude. Furthermore, we demonstrated that the composites possess the essential enthalpy values, competent strength, and ease of shaping, making them applicable across various domains of thermal energy management.

Interfacial Regulation of Rice-Grain-like Iron-Nickel Phosphide Nanorods on Phosphorus-Doped Graphene Architectures as Bifunctional Electrocatalysts for Water Splitting

The design of bimetallic metal-organic frameworks (MOFs) with a hierarchical structure is important to improve the electrocatalytic performance of catalysts due to their synergistic effect on different metal ions. In this work, the catalyst comprises bimetallic iron-nickel MOF-derived FeNi phosphides, intricately integrated with phosphorus-doped reduced graphene oxide architectures (FeNi2P-C/P-rGA) through the hydrothermal and phosphating treatments. The hierarchical architecture of the catalyst is beneficial for exposing active sites and facilitating electron transfer. The FeNi2P-C/P-rGA catalyst exhibits excellent performance in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolytes. Notably, FeNi2P-C/P-rGA requires only the overpotential of 93 and 210 mV to achieve a current density of 10 mA cm-2 for the HER and OER with small values of Tafel slope and charge transfer resistance, respectively. Furthermore, the catalyst exhibits boosted activity for overall water splitting with a low potential of 1.56 V. This work can be considered to extend the design of multilevel catalysts in the application of water splitting.

Modification Strategies for Development of 2D Material-Based Electrocatalysts for Alcohol Oxidation Reaction

2D materials, such as graphene, MXenes (metal carbides and nitrides), graphdiyne (GDY), layered double hydroxides, and black phosphorus, are widely used as electrocatalyst supports for alcohol oxidation reactions (AORs) owing to their large surface area and unique 2D charge transport channels. Furthermore, the development of highly efficient electrocatalysts for AORs via tuning the structure of 2D support materials has recently become a hot area. This article provides a critical review on modification strategies to develop 2D material-based electrocatalysts for AOR. First, the principles and influencing factors of electrocatalytic oxidation of alcohols (such as methanol and ethanol) are introduced. Second, surface molecular functionalization, heteroatom doping, and composite hybridization are deeply discussed as the modification strategies to improve 2D material catalyst supports for AORs. Finally, the challenges and perspectives of 2D material-based electrocatalysts for AORs are outlined. This review will promote further efforts in the development of electrocatalysts for AORs.

Microfibrous Carbon Paper Decorated with High-Density Manganese Dioxide Nanorods: An Electrochemical Nonenzymatic Platform of Glucose Sensing

Nanorod structures exhibit a high surface-to-volume ratio, enhancing the accessibility of electrolyte ions to the electrode surface and providing an abundance of active sites for improved electrochemical sensing performance. In this study, tetragonal α-MnO2 with a large K+-embedded tunnel structure, directly grown on microfibrous carbon paper to form densely packed nanorod arrays, is investigated as an electrocatalytic material for non-enzymatic glucose sensing. The MnO2 nanorods electrode demonstrates outstanding catalytic activity for glucose oxidation, showcasing a high sensitivity of 143.82 µA cm-2 mM-1 within the linear range from 0.01 to 15 mM, with a limit of detection (LOD) of 0.282 mM specifically for glucose molecules. Importantly, the MnO2 nanorods electrode exhibits excellent selectivity towards glucose over ascorbic acid and uric acid, which is crucial for accurate glucose detection in complex samples. For comparison, a gold electrode shows a lower sensitivity of 52.48 µA cm-2 mM-1 within a linear range from 1 to 10 mM. These findings underscore the superior performance of the MnO2 nanorods electrode in both sensitivity and selectivity, offering significant potential for advancing electrochemical sensors and bioanalytical techniques for glucose monitoring in physiological and clinical settings.

Synthesis of Microscopic 3D Graphene for High-Performance Supercapacitors with Ultra-High Areal Capacitance

Despite graphene being considered an ideal supercapacitor electrode material, its use in commercial devices is limited because few methods exist to produce high-quality graphene at a large scale and low cost. A simple method is reported to synthesize 3D graphene by graphenization of coal tar pitch with a K2CO3 catalyst. This produces 3D graphenes with high specific surface areas up to 2113 m2 g-1 and exceptional crystallinity (Raman ID/IG as low as ≈0.15). The material has an outstanding specific capacitance of 182.6 F g-1 at a current density of 1.0 A g-1. This occurs at a mass loading of 30 mg cm-2 which is 3 times higher than commercial requirements, yielding an ultra-high areal capacitance of 5.48 F cm-2. The K2CO3 is recycled and reused over 10 cycles with material quality and electrocapacitive performance of 3D graphene retained and verified after each cycle. The synthesis method and resulting electrocapacitive performance properties create new opportunities for using 3D graphene more broadly in practical supercapacitor devices.

Spatially Confined Radical Addition Reaction for Electrochemical Synthesis of Carboxylated Graphene and its Applications in Water Desalination and Splitting

Due to the chemical stability of graphene, synthesis of carboxylated graphene still remains challenging during the electrochemical exfoliation of graphite. In this work, a spatially confined radical addition reaction which occurs in the sub-nanometer scaled interlayers of the expanded graphene sheets for the electrochemical synthesis of highly stable carboxylated graphene is reported. Here, formate anions act as both intercalation ions and co-reactant acid for the confinement of electro-generated carboxylic radical (●COOH) in the sub-nanometer scaled interlayers, which facilitates the radical addition reaction on graphene sheets. The controllable carboxylation of graphene is realized by tuning the concentration of formate anions in the electrolyte solution. The high crystallinity of the obtained product indicates the occurrence of spatially confined ●COOH addition reaction between the sub-nanometer interlayers of expanded graphite. In addition, the carboxylated graphene have been used for water desalination and hydrogen/oxygen reduction reaction. Therefore, this work provides a new method for the in situ preparation of functionalized graphene through the electrolysis and its applications in water desalination and hydrogen/oxygen reduction reactions.

3D Porous Graphene Architecture Integrated with Cu2O for Enhanced Electrochemical Sensing Performance

Construction and functionalization of a 3D graphene architecture are crucial to harness and extend the unique features of graphene and thus essential for its numerous conventional and novel applications. Herein, a 3D honeycomb-patterned porous graphene architecture is constructed through a facile and low-cost self-assembly process and then integrated with Cu2O nanoparticles via a simple electrodeposition procedure. The 3D porous graphene structure is prepared by the breath figure method using a graphene oxide (GO)-based complex in which GO is modified by a surfactant as the casting material. Benefiting from the intercalation of the surfactant between the GO nanosheets and the fabrication of a 3D porous structure, the aggregation inhibition of GO nanosheets and increases in accessible surface area are realized at both nano- and microscales, resulting in good electrochemical performance. Moreover, the deposition of Cu2O nanoparticles can further improve the electrochemical sensing performance of the porous reduced graphene oxide (rGO) structure. Extremely low detection limit (30.72 nM) with a linear range of 0 μM to 30 μM, excellent anti-interference, repeatability, reproducibility, stability, and high accuracy for actual sample testing are shown when the 3D porous Cu2O/rGO film is applied as an electrochemical sensor for DA detection. This work provides not only a superior electrochemical biosensor but also a simple, yet effective and general strategy for the construction and functionalization of a 3D graphene structure.

Souza AB, Levita DP, Mello CC, da Silva AFM, dos Santos TC, Ronconi CM. Innovating Leishmaniasis Treatment: A Critical Chemist's Review of Inorganic Nanomaterials

Leishmaniasis, a critical Neglected Tropical Disease caused by Leishmania protozoa, represents a significant global health risk, particularly in resource-limited regions. Conventional treatments are effective but suffer from serious limitations, such as toxicity, prolonged treatment courses, and rising drug resistance. Herein, we highlight the potential of inorganic nanomaterials as an innovative approach to enhance Leishmaniasis therapy, aligning with the One Health concept by considering these treatments' environmental, veterinary, and public health impacts. By leveraging the adjustable properties of these nanomaterials─including size, shape, and surface charge, tailored treatments for various diseases can be developed that are less harmful to the environment and nontarget species. We review recent advances in metal-, oxide-, and carbon-based nanomaterials for combating Leishmaniasis, examining their mechanisms of action and their dual use as standalone treatments or drug delivery systems. Our analysis highlights a promising yet underexplored frontier in employing these materials for more holistic and effective disease management.

Instantaneous Thermal Energy for Swift Synthesis of Single-Atom Catalysts for Unparalleled Performance in Metal-Air Batteries and Fuel Cells

Based on experimental and computational evidence, phthalocyanine (Pc) compounds in the form of quaternary-bound metal-nitrogen (N) atoms are the most effective catalysts for oxygen reduction reaction (ORR). However, the heat treatment process used in their synthesis may compromise the ideal structure, causing the agglomeration of transition metals. To overcome this issue, a novel method is developed for synthesizing iron (Fe) single-atom catalysts with ideal structures supported by thermally exfoliated graphene oxide (GO). This is achieved through a short heat treatment of only 2.5 min involving FePc and N, N-dimethylformamide in the presence of GO. According to the synthesis mechanism revealed by this study, carbon monoxide acts as a strong linker between the single Fe atoms and graphene. It facilitates the formation of a structure containing oxygen species between FeN4 and graphene, which provides high activity and stability for the ORR. These catalysts possess an enormous number of active sites and exhibit enhanced activity toward the alkaline ORR. They demonstrate excellent performance when applied to real electrochemical devices, such as zinc-air batteries and anion exchange membrane fuel cells. It is expected that the instantaneous heat treatment method developed in this study will aid in the development of high-performing single-atom catalysts.

Evaporate-casting of curvature gradient graphene superstructures for ultra-high strength structural materials

In contemporary manufacturing, the processing of structural materials plays a pivotal role in enabling the creation of robust, tailor-made, and precise components suitable for diverse industrial applications. Nonetheless, current material forming technologies face challenges due to internal stress and defects, resulting in a substantial decline in both mechanical properties and processing precision. We herein develop a processing strategy toward graphene superstructure with a curvature gradient, which allows us to fabricate robust structural materials with meticulously designed functional shapes. The structure consists of an arc-shaped assembly of graphene nanosheets positioned at co-axial curvature centers. During the dehydration-based evaporate-casting process, the assembly is tightened via capillary effect, inducing local bending. By precisely tuning the axis-center distance and tilt angle, we achieve accurate control over the shape of obtained structure. Notably, internal stress is harnessed to reinforce a designed mortise and tenon structure, resulting in a high joining strength of up to ~200 MPa. This innovative approach addresses the challenges faced by current material forming technologies and opens up more possibilities for the manufacturing of robust and precisely shaped components.

Recent advances in graphene-based electroanalytical devices for healthcare applications

Graphene, with its outstanding mechanical, electrical, and biocompatible properties, stands out as an emerging nanomaterial for healthcare applications, especially in building electroanalytical biodevices. With the rising prevalence of chronic diseases and infectious diseases, such as the COVID-19 pandemic, the demand for point-of-care testing and remote patient monitoring has never been greater. Owing to their portability, ease of manufacturing, scalability, and rapid and sensitive response, electroanalytical devices excel in these settings for improved healthcare accessibility, especially in resource-limited settings. The development of different synthesis methods yielding large-scale graphene and its derivatives with controllable properties, compatible with device manufacturing - from lithography to various printing methods - and tunable electrical, chemical, and electrochemical properties make it an attractive candidate for electroanalytical devices. This review article sheds light on how graphene-based devices can be transformative in addressing pressing healthcare needs, ranging from the fundamental understanding of biology in in vivo and ex vivo studies to early disease detection and management using in vitro assays and wearable devices. In particular, the article provides a special focus on (i) synthesis and functionalization techniques, emphasizing their suitability for scalable integration into devices, (ii) various transduction methods to design diverse electroanalytical device architectures, (iii) a myriad of applications using devices based on graphene, its derivatives, and hybrids with other nanomaterials, and (iv) emerging technologies at the intersection of device engineering and advanced data analytics. Finally, some of the major hurdles that graphene biodevices face for translation into clinical applications are discussed.

Exploring Recent Developments in Graphene-Based Cathode Materials for Fuel Cell Applications: A Comprehensive Overview

Fuel cells are at the forefront of modern energy research, with graphene-based materials emerging as key enhancers of performance. This overview explores recent advancements in graphene-based cathode materials for fuel cell applications. Graphene's large surface area and excellent electrical conductivity and mechanical strength make it ideal for use in different solid oxide fuel cells (SOFCs) as well as proton exchange membrane fuel cells (PEMFCs). This review covers various forms of graphene, including graphene oxide (GO), reduced graphene oxide (rGO), and doped graphene, highlighting their unique attributes and catalytic contributions. It also examines the effects of structural modifications, doping, and functional group integrations on the electrochemical properties and durability of graphene-based cathodes. Additionally, we address the thermal stability challenges of graphene derivatives at high SOFC operating temperatures, suggesting potential solutions and future research directions. This analysis underscores the transformative potential of graphene-based materials in advancing fuel cell technology, aiming for more efficient, cost-effective, and durable energy systems.

Regulating d-Orbital Hybridization of Subgroup-IVB Single Atoms for Efficient Oxygen Reduction Reaction

Highly active single-atom electrocatalysts for the oxygen reduction reaction are crucial for improving the energy conversion efficiency, but they suffer from a limited choice of metal centers and unsatisfactory stabilities. Here, this work reports that optimization of the binding energies for reaction intermediates by tuning the d-orbital hybridization with axial groups converts inactive subgroup-IVB (Ti, Zr, Hf) moieties (MN4) into active motifs (MN4O), as confirmed with theoretical calculations. The competition between metal-ligand covalency and metal-intermediate covalency affects the d-p orbital hybridization between the metal site and the intermediates, converting the metal centers into active sites. Subsequently, dispersed single-atom M sites coordinated by nitrogen/oxygen groups have been prepared on graphene (s-M-N/O-C) catalysts on a large-scale with high-energy milling and pyrolysis. Impressively, the s-Hf-N/O-C catalyst with 5.08 wt% Hf exhibits a half-wave potential of 0.920 V and encouraging performance in a zinc-air battery with an extraordinary cycling life of over 1600 h and a large peak power-density of 256.9 mW cm-2. This work provides promising single-atom electrocatalysts and principles for preparing other catalysts for the oxygen reduction reaction.

Activated carbon and their nanocomposites derived from vegetable and fruit residues for water treatment

Water pollution remains a pressing environmental issue, with diverse pollutants such as heavy metals, pharmaceuticals, dyes, and aromatic hydrocarbon compounds posing a significant threat to clean water access. Historically, biomass-derived activated carbons (ACs) have served as effective adsorbents for water treatment, owing to their inherent porosity and expansive surface area. Nanocomposites have emerged as a means to enhance the absorption properties of ACs, surpassing conventional AC performance. Biomass-based activated carbon nanocomposites (ACNCs) hold promise due to their high surface area and cost-effectiveness. This review explores recent advancements in biomass-based ACNCs, emphasizing their remarkable adsorption efficiencies and paving the way for future research in developing efficient and affordable ACNCs. Leveraging real-time communication for ACNC applications presents a viable approach to addressing cost concerns.

Chemical vapor deposition growth of graphene and other nanomaterials with 3D architectures towards electrocatalysis and secondary battery-related applications

Recently, two-dimensional (2D) layered materials, such as graphene and transition metal dichalcogenides (TMDCs), have garnered a lot of attention in energy storage/conversion-related fields due to their novel physical and chemical properties. Constructing flat graphene and TMDCs nanosheets into 3D architectures can significantly increase their exposed surface area and prevent the restacking of adjacent 2D layers, thus dramatically promoting their applications in various energy-related fields. Chemical Vapor Deposition (CVD) is a low-cost, facile, and scalable method, which has been widely employed to produce high-quality graphene and TMDCs nanosheets with 3D architectures. During the CVD process, the morphologies and properties of the 3D architectures of such 2D materials can be designed by selecting substrates with different compositions, stacking geometries, and micro-structures. In this review, we focus on the recent advances in the CVD synthesis of graphene, TMDCs, and their hybrids with 3D architectures on different 3D-structured substrates, as well as their applications in the electrocatalytic hydrogen evolution reaction (HER) and various secondary batteries. In addition, the challenges and future prospects for the CVD synthesis and energy-related applications of these unique layered materials will also be discussed.

Advancements in Noble Metal-Decorated Porous Carbon Nanoarchitectures: Key Catalysts for Direct Liquid Fuel Cells

Noble-metal nanocrystals have emerged as essential electrode materials for catalytic oxidation of organic small molecule fuels in direct liquid fuel cells (DLFCs). However, for large-scale commercialization of DLFCs, adopting cost-effective techniques and optimizing their structures using advanced matrices are crucial. Notably, noble metal-decorated porous carbon nanoarchitectures exhibit exceptional electrocatalytic performances owing to their three-dimensional cross-linked porous networks, large accessible surface areas, homogeneous dispersion (of noble metals), reliable structural stability, and outstanding electrical conductivity. Consequently, they can be utilized to develop next-generation anode catalysts for DLFCs. Considering the recent expeditious advancements in this field, this comprehensive review provides an overview of the current progress in noble metal-decorated porous carbon nanoarchitectures. This paper meticulously outlines the associated synthetic strategies, precise microstructure regulation techniques, and their application in electrooxidation of small organic molecules. Furthermore, the review highlights the research challenges and future opportunities in this prospective research field, offering valuable insights for both researchers and industry experts.

Recent Advances in Carbon Nanotube Utilization in Perovskite Solar Cells: A Review

Due to their exceptional optoelectronic properties, halide perovskites have emerged as prominent materials for the light-absorbing layer in various optoelectronic devices. However, to increase device performance for wider adoption, it is essential to find innovative solutions. One promising solution is incorporating carbon nanotubes (CNTs), which have shown remarkable versatility and efficacy. In these devices, CNTs serve multiple functions, including providing conducting substrates and electrodes and improving charge extraction and transport. The next iteration of photovoltaic devices, metal halide perovskite solar cells (PSCs), holds immense promise. Despite significant progress, achieving optimal efficiency, stability, and affordability simultaneously remains a challenge, and overcoming these obstacles requires the development of novel materials known as CNTs, which, owing to their remarkable electrical, optical, and mechanical properties, have garnered considerable attention as potential materials for highly efficient PSCs. Incorporating CNTs into perovskite solar cells offers versatility, enabling improvements in device performance and longevity while catering to diverse applications. This article provides an in-depth exploration of recent advancements in carbon nanotube technology and its integration into perovskite solar cells, serving as transparent conductive electrodes, charge transporters, interlayers, hole-transporting materials, and back electrodes. Additionally, we highlighted key challenges and offered insights for future enhancements in perovskite solar cells leveraging CNTs.

Selective ion transport in large-area graphene oxide membrane filters driven by the ionic radius and electrostatic interactions

Filters made of graphene oxide (GO) are promising for purification of water and selective sieving of specific ions; while some results indicate the ionic radius as the discriminating factor in the sieving efficiency, the exact mechanism of sieving is still under debate. Furthermore, most of the reported GO filters are planar coatings with a simple geometry and an area much smaller than commercial water filters. Here, we show selective transport of different ions across GO coatings deposited on standard hollow fiber filters with an area >10 times larger than typical filters reported. Thanks to the fabrication procedure, we obtained a uniform coating on such complex geometry with no cracks or holes. Monovalent ions like Na+ and K+ can be transported through these filters by applying a low electric voltage, while divalent ions are blocked. By combining transport and adsorption measurements with molecular dynamics simulations and spectroscopic characterization, we unravel the ion sieving mechanism and demonstrate that it is mainly due to the interactions of the ions with the carboxylate groups present on the GO surface at neutral pH.

Boron- and Oxygen-Doped π-Extended Helical Nanographene with Circularly Polarised Thermally Activated Delayed Fluorescence

Helical nanographenes have garnered substantial attention owing to their finely adjustable optical and semiconducting properties. The strategic integration of both helicity and heteroatoms into the nanographene structure, facilitated by a boron-oxygen-based multiple resonance (MR) thermally activated delayed fluorescence (TADF), elevates its photophysical and chiroptical features. This signifies the introduction of an elegant category of helical nanographene that combines optical (TADF) and chiroptical (CPL) features. In this direction, we report the synthesis, optical, and chiroptical properties of boron, oxygen-doped Π-extended helical nanographene. The π-extension induces distortion in the DOBNA-incorporated nanographene, endowing a pair of helicenes, (P)-B2NG, and (M)-B2NG exhibiting circularly polarized luminescence with glum of -2.3×10-3 and +2.5×10-3, respectively. B2NG exhibited MR-TADF with a lifetime below 5 μs, and a reasonably high fluorescence quantum yield (50 %). Our molecular design enriches the optical and chiroptical properties of nanographenes and opens up new opportunities in multidisciplinary fields.

Silicon Radical-Induced CH4 Dissociation for Uniform Graphene Coating on Silica Surface

Due to the manufacturability of highly well-defined structures and wide-range versatility in its microstructure, SiO2 is an attractive template for synthesizing graphene frameworks with the desired pore structure. However, its intrinsic inertness constrains the graphene formation via methane chemical vapor deposition. This work overcomes this challenge by successfully achieving uniform graphene coating on a trimethylsilyl-modified SiO2 (denote TMS-MPS). Remarkably, the onset temperature for graphene growth dropped to 720 °C for the TMS-MPS, as compared to the 885 °C of the pristine SiO2. This is found to be mainly from the Si radicals formed from the decomposition of the surface TMS groups. Both experimental and computational results suggest a strong catalytic effect of the Si radicals on the CH4 dissociation. The surface engineering of SiO2 templates facilitates the synthesis of high-quality graphene sheets. As a result, the graphene-coated SiO2 composite exhibits a high electrical conductivity of 0.25 S cm-1. Moreover, the removal of the TMP-MPS template has released a graphene framework that replicates the parental TMS-MPS template on both micro- and nano- scales. This study provides tremendous insights into graphene growth chemistries as well as establishes a promising methodology for synthesizing graphene-based materials with pre-designed microstructures and porosity.

A Skin-Inspired Self-Adaptive System for Temperature Control During Dynamic Wound Healing

The thermoregulating function of skin that is capable of maintaining body temperature within a thermostatic state is critical. However, patients suffering from skin damage are struggling with the surrounding scene and situational awareness. Here, we report an interactive self-regulation electronic system by mimicking the human thermos-reception system. The skin-inspired self-adaptive system is composed of two highly sensitive thermistors (thermal-response composite materials), and a low-power temperature control unit (Laser-induced graphene array). The biomimetic skin can realize self-adjusting in the range of 35-42 °C, which is around physiological temperature. This thermoregulation system also contributed to skin barrier formation and wound healing. Across wound models, the treatment group healed ~ 10% more rapidly compared with the control group, and showed reduced inflammation, thus enhancing skin tissue regeneration. The skin-inspired self-adaptive system holds substantial promise for next-generation robotic and medical devices.

Surface-Constrained Metropolis Monte Carlo: Simulation of Reactions on Triply Periodic Minimal Surfaces

Triply periodic minimal surfaces (TPMS) inspired by nature serve as a foundation for developing novel nanomaterials, such as templated silicas, graphene sponges, and schwarzites, with customizable optical, poroelastic, adsorptive, catalytic, and other properties. Computer simulations of reactions on TPMS using reactive intermolecular potentials hold great promise for constructing and screening potential TPMS with the desired properties. Here, we developed an off-lattice, surface-constrained Metropolis Monte Carlo (SC-MMC) algorithm that utilized a temperature quench process. The presented SC-MMC algorithm was used to investigate the process of graphitization reactions on the Schwarz primitive, Schwarz diamond, and Schoen gyroid TPMS, all with a cubic lattice parameter of 8 nm. We show that the optimized carbon TPMS exhibits a low energy, approximately -7.1 eV/atom, comparable to that of graphite and diamond crystals, along with a variety of topological defects. Furthermore, these structures showcase extensive and smooth surfaces characterized by a negative discrete Gaussian curvature, a distinctive feature indicative of an interconnected morphology. They possess specific surface areas of ∼2700 m2/g, comparable to graphene, and exhibit a significant porosity of around 90%. The theoretical X-ray correlation functions and nitrogen adsorption isotherms confirm that the constructed TPMS exhibit remarkably similar surface properties, although the pore space topology varies significantly.

Three-Dimensional Graphene Sheet-Carbon Veil Thermoelectric Composite with Microinterfaces for Energy Applications

Over the years, various processing techniques have been explored to synthesize three-dimensional graphene (3DG) composites with tunable properties for advanced applications. In this work, we have demonstrated a new procedure to join a 3D graphene sheet (3DGS) synthesized by chemical vapor deposition (CVD) with a commercially available carbon veil (CV) via cold rolling to create 3DGS-CV composites. Characterization techniques such as scanning electron microscopy (SEM), Raman mapping, X-ray diffraction (XRD), electrical resistance, tensile strength, and Seebeck coefficient measurements were performed to understand various properties of the 3DGS-CV composite. Extrusion of 3DGS into the pores of CV with multiple microinterfaces between 3DGS and the graphitic fibers of CV was observed, which was facilitated by cold rolling. The extruded 3D graphene revealed pristine-like behavior with no change in the shape of the Raman 2D peak and Seebeck coefficient. Thermoelectric (TE) power generation and photothermoelectric responses have been demonstrated with in-plane TE devices of various designs made of p-type 3DGS and n-type CV couples yielding a Seebeck coefficient of 32.5 μV K-1. Unlike various TE materials, 3DGS, CV, and the 3DGS-CV composite were very stable at high relative humidity. The 3DGS-CV composite revealed a thin, flexible profile, good moisture and thermal stability, and scalability for fabrication. These qualities allowed it to be successfully tested for temperature monitoring of a Li-ion battery during charging cycles and for large-area temperature mapping.

Bubble-Mediated Production of Few-Layer Graphene via Vapor-Liquid Reaction between Carbon Dioxide and Magnesium Melt

It is urgent to develop novel technologies to convert carbon dioxide to graphene. In this work, a bubble-mediated approach via a chemical reaction between carbon dioxide gas and magnesium melt to fabricate a few-layer graphene was illustrated. The morphology and defects of graphene can be regulated by manipulating the melt temperature. The preparation of graphene at 720 °C exhibited an excellent quality of surface and graphitization degree. The high-quality few-layer graphene can be grown under the combined effect of carbon dioxide bubbles and in-situ grown MgO. This preparation method possesses the advantages of high efficiency, low cost, and environmental protection, which may provide a new strategy for the recovery and reuse of greenhouse gases.

Electrochemical and Electrical Biosensors for Wearable and Implantable Electronics Based on Conducting Polymers and Carbon-Based Materials

Bioelectronic devices are designed to translate biological information into electrical signals and vice versa, thereby bridging the gap between the living biological world and electronic systems. Among different types of bioelectronics devices, wearable and implantable biosensors are particularly important as they offer access to the physiological and biochemical activities of tissues and organs, which is significant in diagnosing and researching various medical conditions. Organic conducting and semiconducting materials, including conducting polymers (CPs) and graphene and carbon nanotubes (CNTs), are some of the most promising candidates for wearable and implantable biosensors. Their unique electrical, electrochemical, and mechanical properties bring new possibilities to bioelectronics that could not be realized by utilizing metals- or silicon-based analogues. The use of organic- and carbon-based conductors in the development of wearable and implantable biosensors has emerged as a rapidly growing research field, with remarkable progress being made in recent years. The use of such materials addresses the issue of mismatched properties between biological tissues and electronic devices, as well as the improvement in the accuracy and fidelity of the transferred information. In this review, we highlight the most recent advances in this field and provide insights into organic and carbon-based (semi)conducting materials' properties and relate these to their applications in wearable/implantable biosensors. We also provide a perspective on the promising potential and exciting future developments of wearable/implantable biosensors.

All-Solid-State Mg-Air Battery Enhanced with Free-Standing N-Doped 3D Nanoporous Graphene

Nitrogen (N) doping of graphene with a three-dimensional (3D) porous structure, high flexibility, and low cost exhibits potential for developing metal-air batteries to power electric/electronic devices. The optimization of N-doping into graphene and the design of interconnected and monolithic graphene-based 3D porous structures are crucial for mass/ion diffusion and the final oxygen reduction reaction (ORR)/battery performance. Aqueous-type and all-solid-state primary Mg-air batteries using N-doped nanoporous graphene as air cathodes are assembled. N-doped nanoporous graphene with 50-150 nm pores and ≈99% porosity is found to exhibit a Pt-comparable ORR performance, along with satisfactory durability in both neutral and alkaline media. Remarkably, the all-solid-state battery exhibits a peak power density of 72.1 mW cm-2 ; this value is higher than that of a battery using Pt/carbon cathodes (54.3 mW cm-2 ) owing to the enhanced catalytic activity induced by N-doping and rapid air breathing in the 3D porous structure. Additionally, the all-solid-state battery demonstrates better performances than the aqueous-type battery owing to slow corrosion of the Mg anode by solid electrolytes. This study sheds light on the design of free-standing and catalytically active 3D nanoporous graphene that enhances the performance of both Mg-air batteries and various carbon-neutral-technologies using neutral electrolytes.

Renewable Carbonaceous Materials from Biomass in Catalytic Processes: A Review

This review paper delves into the diverse ways in which carbonaceous resources, sourced from renewable and sustainable origins, can be used in catalytic processes. Renewable carbonaceous materials that come from biomass-derived and waste feedstocks are key to developing more sustainable processes by replacing traditional carbon-based materials. By examining the potential of these renewable carbonaceous materials, this review aims to shed light on their significance in fostering environmentally conscious and sustainable practices within the realm of catalysis. The more important applications identified are biofuel production, tar removal, chemical production, photocatalytic systems, microbial fuel cell electrodes, and oxidation applications. Regarding biofuel production, biochar-supported catalysts have proved to be able to achieve biodiesel production with yields exceeding 70%. Furthermore, hydrochars and activated carbons derived from diverse biomass sources have demonstrated significant tar removal efficiency. For instance, rice husk char exhibited an increased BET surface area from 2.2 m2/g to 141 m2/g after pyrolysis at 600 °C, showcasing its effectiveness in adsorbing phenol and light aromatic hydrocarbons. Concerning chemical production and the oxidation of alcohols, the influence of biochar quantity and pre-calcination temperature on catalytic performance has been proven, achieving selectivity toward benzaldehyde exceeding 70%.

Defect-guided self-tearing in graphene

The two-dimensional to three-dimensional configuration transition through self-tearing promises the engineering and promising applications of graphene. However, it is challenging to control the tearing path on demand through common thermal and interfacial treatments. In this manuscript, a defect-guided self-tearing technique is proposed to generate wider, longer, and even curved and serrated configurations, which is impossible for defect-free graphene. The underlying tearing mechanisms regarding the advancing displacement are disclosed through molecular dynamics simulations and theoretical model. This study provides a useful guidance to the implementation of complex and functional three-dimensional graphene structures.

Ferroelectricity of ice nanotube forests grown in three-dimensional graphene: the electric field effect

Generating diverse ferroelectric ice nanotubes (NTs) efficiently has always been challenging, but matters in nanomaterial synthesis and processing technology. In the present work, we propose a method of growing ice NT forests in a single cooling process. A three-dimensional (3D) graphene structure was selected to behave as a representative container in which a batch of (5, 0) ice NTs was formed simultaneously under the cooling process from molecular dynamics simulation. Other similar 3D graphene structures but with different hole configurations, like uniform triangle or both triangle and pentagon, were also tested, revealing that ice NTs with different tube indices, i.e. both (3, 0) and (5, 0), could also be formed at the same time. Intriguingly, the orientations of the dipole moments of the water molecules of an ice NT formed were independent of each other, making the net ferroelectricity of the whole system weakened or even cancelled. An electric field could help change the orientation of the water molecules of the already obtained ice NTs and even twist the tube to be a spiral (5, 1) one if it was applied during the cooling process, such that the net ferroelectricity was greatly improved. The underlying physical mechanism of all phase transition phenomena, including the improvement of the ferroelectricity under an electric field, were explored in depth from the phase transition curves and structural point of view. The obtained results are of significant application value for improving the preparation efficiency of nano-ferroelectric materials, which are prosperous in nano-devices.

Application and Development of Smart Thermally Conductive Fiber Materials

In recent years, with the rapid advancement in various high-tech technologies, efficient heat dissipation has become a key issue restricting the further development of high-power-density electronic devices and components. Concurrently, the demand for thermal comfort has increased; making effective personal thermal management a current research hotspot. There is a growing demand for thermally conductive materials that are diversified and specific. Therefore, smart thermally conductive fiber materials characterized by their high thermal conductivity and smart response properties have gained increasing attention. This review provides a comprehensive overview of emerging materials and approaches in the development of smart thermally conductive fiber materials. It categorizes them into composite thermally conductive fibers filled with high thermal conductivity fillers, electrically heated thermally conductive fiber materials, thermally radiative thermally conductive fiber materials, and phase change thermally conductive fiber materials. Finally, the challenges and opportunities faced by smart thermally conductive fiber materials are discussed and prospects for their future development are presented.

Polymer Coating with Balanced Coordination Strength and Ion Conductivity for Dendrite-Free Zinc Anode

Decorating Zn anodes with functionalized polymers is considered as an effective strategy to inhibit dendrite growth. However, this normally brings extra interfacial resistance rendering slow reaction kinetics of Zn2+ . Herein, a poly(2-vinylpyridine) (P2VP) coating with modulated coordination strength and ion conductivity for dendrite-free Zn anode is reported. The P2VP coating favors a high electrolyte wettability and rapid Zn2+ migration speed (Zn2+ transfer number, tZn 2+ = 0.58). Electrostatic potential calculation shows that P2VP mildly coordinates with Zn2+ (adsorption energy = -0.94 eV), which promotes a preferential deposition of Zn along the (002) crystal plane. Notably, the use of partially (26%) quaternized P2VP (q-P2VP) further reduces the interfacial resistance to 126 Ω, leading to a high ion migration speed (tZn 2+ = 0.78) and a considerably low nucleation overpotential (18 mV). As a result of the synergistic effect of mild coordination and partial electrolysis, the overpotential of the q-P2VP-decorated Zn anode retains at a considerably low level (≈46 mV) over 1000 h at a high current density of 10 mA cm-2 . The assembled (NH4 )2 V6 O16 ·1.5H2 O || glass fiber || q-P2VP-Zn full cell reveals a lower average capacity decay rate of only 0.018% per cycle within 500 cycles at 1 A g-1 .