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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. [ABSTRACT FROM AUTHOR]

Recent advances in the growth of carbon nanowalls (CNWs) and vertical graphene nanosheets using various plasma‐enhanced chemical vapor deposition (PECVD) methods are reviewed in this article. Growth methods are classified into hot‐ and cold‐wall reactors equipped with diverse plasma generation systems, and their respective characteristics are summarized, with particular attention to the behavior of reactive species, such as ions and radicals, generated within the plasma. Recent progress in this research domain is outlined for each method, and an organized account of the chemical kinetic phenomena occurring within the plasma is provided. Finally, future perspectives are discussed. Fundamental data are obtained through real‐time in situ measurements of ions and radicals, and the construction of a database from these data offers microscopic insights that significantly enhance processing outcomes for macroscopically controlling the mechanical shapes and chemical properties of CNWs. [ABSTRACT FROM AUTHOR]

The increasing utilization of terahertz (THz) bandwidth in both industrial and private sectors highlights the significance of efficient terahertz shielding and absorption devices. These devices play a crucial role in safeguarding electronic components from disruptive effects and rendering objects less detectable by radar systems. However, the limited availability of materials and devices hinders progress in this field. In this study, a strain engineering route is presented for the active control of terahertz shielding and absorption properties in 3D graphene through the application of mechanical strain. A straintronic modulator based on 3D graphene is demonstrated, capable of modulating absorption and reflection of THz radiation in real‐time over a wide range of 0.1–3 THz. The modulator can be tuned to exhibit either shielding capability with a specific shielding effectiveness of 0.3 × 105 dB cm2 g−1 or stealth characteristics with an average reflection loss of 25 dB and 99.4% absorption. These findings open new avenues for leveraging 2D materials in their 3D porous form, where strain‐induced changes in interlayer interactions enable control over the properties of these materials. This discovery unveils vast unexplored physical phenomena with immense potential for advanced THz imaging, radar, and electromagnetic applications. [ABSTRACT FROM AUTHOR]

The exceptional potential of three-dimensional (3D) graphene materials for ultra-high methane and hydrogen storage is explored in this study, utilizing the grand canonical Monte Carlo (GCMC) molecular simulation method. The 3D boron nitride (BN) graphene materials, synthesized through the substitution of boron and nitrogen for carbon atoms, exhibit superior adsorption capacities. At 298 K, the weight adsorption capacities of two BN materials for methane reach up to 1.134 g/g and 0.82 g/g, respectively, at 30 MPa, significantly exceeding the DOE target of 0.5 g/g. For hydrogen, remarkably, at 77 K and pressures exceeding 1 MPa, the weight adsorption capacity surpasses 5.5 wt%, achieving an impressive 27 wt% at 30 MPa, nearly quintupling the DOE’s hydrogen storage target. Although the volumetric adsorption capacity is lower compared to Metal-Organic Frameworks (MOFs), the 3D graphene materials’ weight adsorption performance positions them as strong contenders for next-generation energy storage solutions. The GCMC simulations substantiate the significance of 3D graphene materials as highly promising adsorbents for efficient methane and hydrogen storage.

In this study, we comprehensively investigated the scaling law for elastic properties of three-dimensional honeycomb-like graphenes (3D graphenes) using hybrid neural network potential-based molecular dynamics simulations and theoretical analyses. The elastic constants were obtained as functions of honeycomb hole size, denoted by the graphene wall length L. All five independent elastic constants in the large-L limit are proportional to L−1. The associated coefficients are combinations of elastic constants of two-dimensional graphene. High-order terms including L−2 and L−3 emerge for finite L values. They have three origins, the distorted areas close to the joint lines of 3D graphenes, the variation in solid angles between graphene plates, and the bending distortion of graphene plates. Significantly, the chirality becomes essential with decreasing L because the joint line structures are different between the armchair and zigzag-type 3D graphenes. Our findings provide insights into the elastic properties of graphene-based superstructures and can be used for further studies on graphene-based materials. [ABSTRACT FROM AUTHOR]

Epidermal electrodes play an essential role in accurately capturing electrophysiological signals, which are critical for human health monitoring and human–computer interactions. However, these electrodes face challenges such as the inability to maintain long-term adhesion and limited adaptability to skin deformation, which hinder their sustained and repeated use. In this work, we developed a stretchable and sweat-adhesive epidermal electrode for accurate recording of electromyography (EMG) signals. This electrode is based on the chemical vapor deposition (CVD) of graphene foam and eutectogel. This copolymer exhibits excellent tensile properties (500–600%), sweat adhesion (19 kPa), and low impedance (99 Ω). It provides both structural support and an interfacial conductive medium for the graphene foam, effectively reducing contact impedance with skin. This stretchable and sweat-adhesive epidermal electrode presents an interesting scheme for the preparation of wearable devices. [ABSTRACT FROM AUTHOR]

Spatial graphene is a 3D structure of a 2D material that preserves its main features. Its production can be originated from the water solution of graphene oxide (GO). The main steps of the method include the crosslinking of flakes of graphene via treatment with hydrazine, followed by the reduction of the pillared graphene oxide (pGO) with hydrogen overpressure at 700 °C, and further decoration with catalytic metal (palladium). Experimental research achieved the formation of reduced pillared graphene oxide (r:pGO), a porous material with a surface area equal to 340 m2/g. The transition from pGO to r:pGO was associated with a 10-fold increase in pore volume and the further reduction of remaining oxides after the action of hydrazine. The open porosity of this material seems ideal for potential applications in the energy industry (for hydrogen storage, in batteries, or in electrochemical and catalytic processes). The hydrogen sorption potential of the spatial graphene-based material decorated with 6 wt.% of palladium reached 0.36 wt.%, over 10 times more than that of pure metal. The potential of this material for industrial use requires further refining of the elaborated procedure, especially concerning the parameters of substrate materials. [ABSTRACT FROM AUTHOR]

Defect engineering can give birth to novel properties for adsorption and photocatalysis in the control of antibiotics and heavy metal combined pollution with photocatalytic composites. However, the role of defects and the process mechanism are complicated and indefinable. Herein, TiO2/CN/3DG was fabricated and defects were introduced into the tripartite structure with separate O2 plasma treatment for the single component. We find that defect engineering can improve the photocatalytic activity, attributing to the increase of the contribution from h+ and OH. In contrast to TiO2/CN/3DG with a photocatalytic tetracycline removal rate of 75.2%, the removal rate of TC with D‐TiO2/CN/3DG has increased to 88.5%. Moreover, the reactive sites of tetracycline can be increased by adsorbing on the defective composites. The defect construction on TiO2 shows the advantages in tetracycline degradation and Cu2+ adsorption, but also suffers significant inhibition for the tetracycline degradation in a tetracycline/Cu2+ combined system. In contrast, the defect construction on graphene can achieve the cooperative removal of tetracycline and Cu2+. These findings can provide new insights into water treatment strategies with defect engineering. [ABSTRACT FROM AUTHOR]

Abstract The increasing utilization of terahertz (THz) bandwidth in both industrial and private sectors highlights the significance of efficient terahertz shielding and absorption devices. These devices play a crucial role in safeguarding electronic components from disruptive effects and rendering objects less detectable by radar systems. However, the limited availability of materials and devices hinders progress in this field. In this study, a strain engineering route is presented for the active control of terahertz shielding and absorption properties in 3D graphene through the application of mechanical strain. A straintronic modulator based on 3D graphene is demonstrated, capable of modulating absorption and reflection of THz radiation in real‐time over a wide range of 0.1–3 THz. The modulator can be tuned to exhibit either shielding capability with a specific shielding effectiveness of 0.3 × 105 dB cm2 g−1 or stealth characteristics with an average reflection loss of 25 dB and 99.4% absorption. These findings open new avenues for leveraging 2D materials in their 3D porous form, where strain‐induced changes in interlayer interactions enable control over the properties of these materials. This discovery unveils vast unexplored physical phenomena with immense potential for advanced THz imaging, radar, and electromagnetic applications.

Treatment of dye polluted water using sustainable and efficient approaches is essential to mitigate the detrimental effects of dyes. The present work reports on the adsorption effectiveness of a graphene-based adsorbent configured into a practical engineering structure, namely three-dimensional graphene oxide integrated with chitosan biopolymer (3D-GCB). This unique graphene configuration enabled its application in continuous fixed-bed adsorption of Metanil Yellow (MY) and Remazol Black B (RBB) dyes from polluted water for the first time. The breakthrough attributes of the fixed-bed of 3D-GCB were established in terms of bed depth (3 – 5 cm), influent concentration (100 – 200 mg/L for MY and 100 – 300 mg/L for RBB) and feed flowrate (2 – 4 mL/min). The greatest bed adsorption capacities attained were 157.06 and 247.96 mg/g for MY and RBB, respectively. The column parameters for obtaining these results were 5 cm bed depth, 2 mL/min feed flowrate, and 150 and 200 mg/L influent concentrations respectively for MY and RBB. The fixed-bed performance of the 3D-GCB was well correlated to the Thomas and Yoon-Nelson models, and the corresponding kinetic properties were determined. Furthermore, the higher affinity of the 3D-GCB for RBB as compared to MY was elucidated based on the ionic strengths of the dye molecule. The utilisation of sustainable and renewable raw materials, such as graphite and chitosan, have resulted in a 3D-GCB production cost of approximately RM 10.72 per gram. This work revealed the suitability of 3D-GCB as the state-of-the-art graphene composite for continuous adsorption of anionic dyes, specifically MY and RBB.

Designing and synthesizing cost-effective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts is still the critical impetus for electrocatalytic alkaline water splitting for green hydrogen production. We present a novel strategy to synthesize Ni 12 P 5 –Ni 2 P heterojunction nanoparticles anchored in the three-dimensional (3D) graphene composite bonded by N–P co-doped porous carbon (NPC) through a single high-temperature carbonization. The as-obtained Ni 12 P 5 –Ni 2 P@NPC/3DG possessed an open pore structure, promoting electrolyte diffusion and enhance bubble release. The synergistic effect of the Ni 12 P 5 –Ni 2 P heterojunction with high intrinsic catalytic activity and the N–P co-doped carbon enabled the composite to exhibit high catalytic activity and stability for HER and OER. The optimized Ni 12 P 5 –Ni 2 P@NPC/3DG-0.5 exhibited overpotentials of 209.8/206.1 mV at 10 mA cm−2 and Tafel slopes of 67.9/92.3 mV dec−1 for HER/OER. Furthermore, when Ni 12 P 5 –Ni 2 P@NPC/3DG-0.5 was used as both the cathode and anode for overall water splitting, the cell only required a low voltage of 1.58 V to achieve a current density of 10 mA cm−2, which was comparable to the catalytic activities of commercial noble metal catalysts. Meaningfully, this synthetic method provided a new strategy to improve electrocatalytic performance of Ni-based phosphides, extensively promoting the development of highly efficient electrocatalysts for alkaline overall water splitting. • A new strategy achieved Ni 12 P 5 –Ni 2 P/3D graphene bonded by N–P co-doped carbon. • Ni 12 P 5 –Ni 2 P@NPC/3DG showed good bifunctional catalyticity for water splitting. • The anchoring of Ni 12 P 5 –Ni 2 P on NPC/3DG facilitated the activity and durability. • The synthesis strategy was cost-effective, simple, eco-friendly and referenceable. [ABSTRACT FROM AUTHOR]

The increasing demand for miniature, flexible electronic devices have fueled the need for compact and high‐performing energy storage solutions. Microsupercapacitors (mSCs) with reduced dimension and novel electrode design have gained prominence. This concept paper summarizes and views the recent advancements in mSCs with a focus on 3D graphene electrodes and their novel electrode design to increase energy performance of the devices. Especially, we focus on these 3D graphene structures fabricated using a laser‐scribing method which offer an efficient, cost‐effective approach for enhanced mSC performance. Further, this work delves into the vital link between the electrical field effect and geometrically engineered interdigitated electrodes, which is pivotal for maximizing the ion transport and mSC energy storage performance. The insights presented here are promising for meeting the power requirements of future miniature electronics. [ABSTRACT FROM AUTHOR]

Abstract The increasing demand for miniature, flexible electronic devices have fueled the need for compact and high‐performing energy storage solutions. Microsupercapacitors (mSCs) with reduced dimension and novel electrode design have gained prominence. This concept paper summarizes and views the recent advancements in mSCs with a focus on 3D graphene electrodes and their novel electrode design to increase energy performance of the devices. Especially, we focus on these 3D graphene structures fabricated using a laser‐scribing method which offer an efficient, cost‐effective approach for enhanced mSC performance. Further, this work delves into the vital link between the electrical field effect and geometrically engineered interdigitated electrodes, which is pivotal for maximizing the ion transport and mSC energy storage performance. The insights presented here are promising for meeting the power requirements of future miniature electronics.

Less defective, nitrogen-doped 3-dimensional graphene (N3DG) and defect-rich, nitrogen-doped 3-dimensional graphene (N3DG-D) were made by the thermal CVD (Chemical Vapor Deposition) process via varying the carbon precursors and synthesis temperature. These modified 3D graphene materials were compared with pristine 3-dimensional graphene (P3DG), which has fewer defects and no nitrogen in its structure. The different types of graphene obtained were characterized for morphological, structural, and compositional assessment through Scanning Electron Microscopy (SEM), Raman Spectroscopy, and X-ray Photoelectron Spectroscopy (XPS) techniques. Electrodes were fabricated, and electrochemical characterizations were conducted to evaluate the suitability of the three types of graphene for heavy metal sensing (lead) and Electric Double-Layer Capacitor (EDLC) applications. Initially, the various electrodes were treated with a mixture of 2.5 mM Ruhex (Ru (NH3)6Cl3 and 25 mM KCl to confirm that all the electrodes underwent a reversible and diffusion-controlled electrochemical process. Defect-rich graphene (N3DG-D) revealed the highest current density, followed by pristine (P3DG) and less-defect graphene (N3DG). Further, the three types of graphene were subjected to a sensing test by square wave anodic stripping voltammetry (SWASV) for lead detection. The obtained preliminary results showed that the N3DG material provided a great lead-sensing capability, detecting as little as 1 µM of lead in a water solution. The suitability of the electrodes to be employed in an Electric Double-Layer Capacitor (EDLC) was also comparatively assessed. Electrochemical characterization using 1 M sodium sulfate electrolyte was conducted through cyclic voltammetry and galvanostatic charge-discharge studies. The voltammogram and the galvanostatic charge-discharge (GCD) curves of the three types of graphene confirmed their suitability to be used as EDLC. The N3DG electrode proved superior with a gravimetric capacitance of 6.1 mF/g, followed by P3DG and N3DG, exhibiting 1.74 mF/g and 0.32 mF/g, respectively, at a current density of 2 A/g. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Increasing demand for pure, safe, and affordable water is one of the biggest challenges worldwide. Various pollutants such as dyes, heavy metals, bacteria, pesticides, and pharmaceuticals are present in water and their removal is the major challenge for us. In this respect, various materials have been developed to remove the various types of pollutants from wastewater. Recently, 3D graphene‐based materials (3D GBMs) have received a great deal of attention in wastewater treatment due to their extraordinary properties. The large surface area, porous structure, versatile surface chemistry with exceptional physiochemical properties such as mechanical and electrical properties, and excellent thermal and chemical stability make them excellent absorbent candidates for wastewater treatment. The materials properties of 3D graphene‐based materials (3D GBMs) and their environmental performance as well as the key parameters that influence their capacities for removal of pollutants from the wastewater have also been discussed. The aim of this review is to provide the recent progress in removing several water pollutants like dye, oil, organic solvents, heavy metal ions, bacteria, and pathogens from wastewater. Furthermore, this review also contains the future development opportunities and technical challenges of 3‐D graphene‐based materials in wastewater treatment. [ABSTRACT FROM AUTHOR]

Tin monosulfide (SnS) serves as a promising anode material in lithium-ion batteries (LIBs) due to its high theoretical capacity. However, its low rate capability and cycle stability due to poor electrical conductivity and large volume change remain urgent issues to be resolved. Here, we provide an efficient and facile strategy to achieve three-dimensional (3D) freestanding sulfur and nitrogen co-doped SnS/graphene nanocomposite (SnS/3DSNG). Benefiting from excellent electronic conductivity, improved volume flexibility, short transport length, and numerous active sites, the nanocomposite exhibits high initial discharge capacity (1030 mA h g−1 at 1 A g−1), excellent cycling stability (530 mA h g−1 at 1 A g−1 after 500 cycles) and great rate performance. The pseudo-capacitance can be improved (93.9 % at 1 mV s−1) by regulating the ratio of S and N co-doped graphene (3DSNG) and SnS. This study presents an efficient and simple method to improve the electrochemical performance of SnS-based lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized l-arginine-functionalized 3D macroporous graphene, formed through the assembling of reduced graphene oxide nanosheets. The soil pH microsensor is fabricated on the patterned Si/SiO2 substrates with Au-interdigitated electrodes employing 3D graphene/l-arginine structure as a sensing platform. The sensor exhibits an increase in conductance toward an increase in pH of the buffer solutions (pH = 3–10) with a sensitivity of 97 μS/pH and response of 650%. The room-temperature pH sensing measurements are performed to detect the pH variations in different types of soil samples. The conductance of the sensor is correlated to the change in soil pH with increase of gravimetric moisture contents displaying a sensitivity of 105 μS/pH and 98 μS/pH for black soil and red soil, respectively. The sensor effectively detects soil pH changes against varying concentrations of CaCl2 solution (1–20 mM) with a sensitivity of 121 μS/pH (black soil) and 101 μS/pH (red soil). In comparison to the commercial pH meter, the 3D graphene/l-arginine-based microsensor demonstrates a relative standard deviation of less than 4% in soil pH sensing measurements. The designed pH sensor displays an excellent response with good reversibility, satisfactory linearity, low hysteresis (3%), a response time of 30–35 s, and stability of around 2 months. [ABSTRACT FROM AUTHOR]

A 3D graphene foam made of interconnected multilayer graphene flakes was produced on optical fibres (OF) by laser-induced transformation of a polyimide (PI) film coated on the OF cladding. This material, known as laser-induced graphene (LIG), was explored in the electrochemical detection and quantification of dopamine (DA) at physiologically relevant concentrations in the presence of the most relevant interfering molecules in biological fluids, ascorbic acid (AA) and uric acid (UA). The measured limit of detection is 100 nM, the linear range is 0.1 to 5.0 μM and a maximum sensitivity of 5.0 µA µM−1 cm−2 was obtained for LIG decorated with Pt nanoparticles (NPs). Moreover, immunity to AA and UA interference and to fouling was attained by decorating the LIG electrode with Pt NPs and coating it with Nafion. These figures of merit underline the potential of these sensors for the quantification of physiologically relevant concentrations of DA in biological fluids, paving the way for the development of hybrid electrochemical/optical sensing actuating platforms in a lab-on-fibre configuration, with relevant applications in biomedical engineering. The advantages of this hybrid arrangement include the possibility of in situ counterproofing, extended measuring ranges, photoelectrochemical detection and the probing of inaccessible places. This elegant approach can also provide a simple and cost-effective way to fabricate biomedical devices with extended functionality, such as medical optical probes with added electrochemical capabilities and optogenetics combined with local electrochemical detection, among others. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Increasing both clean water and green energy demands for survival and development are the grand challenges of our age. Here, we successfully fabricate a novel multifunctional 3D graphene-based catalytic membrane (3D-GCM) with active metal nanoparticles (AMNs) loading for simultaneously obtaining the water purification and clean energy generation, via a “green” one-step laser scribing technology. The as-prepared 3D-GCM shows high porosity and uniform distribution with AMNs, which exhibits high permeated fluxes (over 100 L m−2 h−1) and versatile super-adsorption capacities for the removal of tricky organic pollutants from wastewater under ultra-low pressure-driving (0.1 bar). After adsorption saturating, the AMNs in 3D-GCM actuates the advanced oxidization process to self-clean the fouled membrane via the catalysis, and restores the adsorption capacity well for the next time membrane separation. Most importantly, the 3D-GCM with the welding of laser scribing overcomes the lateral shear force damaging during the long-term separation. Moreover, the 3D-GCM could emit plentiful of hot electrons from AMNs under light irradiation, realizing the membrane catalytic hydrolysis reactions for hydrogen energy generation. This “green” precision manufacturing with laser scribing technology provides a feasible technology to fabricate high-efficient and robust 3D-GCM microreactor in the tricky wastewater purification and sustainable clean energy production as well.

Previously, we reported 3D Shaped 3D Graphene (3D2G) with controlled structural design. In this work, we introduced cold rolling as a post-processing technique to obtain compressed 3D2G, referred here as C3D2G, and investigated the relationship between its microstructure and properties. The performed comprehensive materials characterization of C3D2G revealed the micro-motion of the graphene flakes from their random orientations into a stacked and aligned structure along with the extrusion of bulk material into the structural pores which acted as stress-relief spaces. The obtained new bulk morphology significantly enhanced its properties. The achieved gravimetric density, electrical conductivity, and tensile strength of C3D2G were higher than 3D2G by 37.3, 53.4, and 24.9 times, respectively. A new process was demonstrated based on the observed extrusion enabling the welding of multiple pieces of 3D2G into one structure via cold rolling, thus showing potential for dimensional scaling up. The conducted tensile and electrical conductivity studies across the welded region revealed the presence of a mechanical bond within the joined area with a higher strength than the initial pieces involved in welding. Further, a unique application of this material was explored as a reusable, etch-resistant hard mask for patterning silicon wafers, and as a protective barrier against fluorine plasma environment. The etch rate measurements showed a higher etching resistance of C3D2G compared to Si and SiO 2 when exposed to a fluorine plasma Reactive Ion Etching (RIE). [Display omitted] [ABSTRACT FROM AUTHOR]

The hydrogenated amorphous carbon (a-C:H) film, which is widely used in the engineering field, has attracted more and more researchers' attention. A-C:H films exhibit super-low friction coefficient and low wear in inert atmospheres but high friction coefficient and wear in ambient air. In this study, 3D graphene and h-BN were used as solid lubricants to reduce the friction and wear of steel-a-C:H film contact conditions under different loads. When 0.01 wt% of 3D graphene and 0.1 wt% h-BN were mixed at a volume ratio of 1:1, the lubricating effect is optimum. Compared with a-C:H films, not only the friction coefficient is reduced, but also the wear rate is further reduced. This is mainly due to the formation of an ordered and dense transfer film on the sliding interface, which effectively prevents the direct contact between the surfaces of the friction pair. [ABSTRACT FROM AUTHOR]

3D graphene not only maintains the excellent properties of 2D graphene, but also has the advantages of low density, high porosity, large specific surface area and so on. However, with the continuous development of graphene-based composites, there is an urgent need to inject new functional components on the basis of 3D graphene structures to achieve different applications. The introduction of crosslinking agents makes macroscopic 3D graphene with special structure and excellent performance, as well as a variety of application prospects. This paper reviewed the recent advances for preparation of 3D graphene based on crosslinking reagents, respectively from crosslinking mechanism, crosslinking agent, and effect of crosslinking agent on properties of 3D graphene. Finally, existent challenges and prospects involved crosslinking reagents were also discussed, providing references for subsequent studies. [ABSTRACT FROM AUTHOR]

Graphene is a promising material that may be potentially used in biomedical applications, mainly for drug delivery applications. In our study, we propose an inexpensive 3D graphene preparation method by wet chemical exfoliation. The morphology of the graphene was studied by SEM and HRTEM. Moreover, the volumetric elemental composition (C, N, and H) of the materials was analyzed, and Raman spectra of prepared graphene samples were obtained. X-ray photoelectron spectroscopy, relevant isotherms, and specific surface area were measured. Survey spectra and micropore volume calculations were made. In addition, the antioxidant activity and hemolysis rate in contact with blood were determined. Activity against free radicals of graphene samples before and after thermal modification was tested using the DPPH method. The RSA of the material increased after graphene modification, which suggests that antioxidant properties were improved. All tested graphene samples caused hemolysis in the range of 0.28–0.64%. The results showed that all tested 3D graphene samples might be classified as nonhemolytic. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel graphene foams are shown to be ideal electrodes for glucose biosensors. • XPS and Raman characterise electrodes and their modification with pyrene-NHS. • GDH successfully immobilised on pyrene-NHS functionalised graphene foam. • Linear response to increasing glucose concentration over suitable range. • Glucose sensitivity of 22.7 μA/mM/cm^2 shows promise of this metal-free sensor. We adapted a single-step method to functionalise three-dimensional graphene foam (Gii-Sens) electrodes with a 1-pyrenebutyric acid N-hydroxysuccinimide ester (Pyr-NHS). The physical and chemical properties of these functionalised electrodes were subsequently probed via Raman spectroscopy, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy. Combined with data acquired from cyclic voltammetry and electrical impedance spectroscopy, we confirmed the presence of Pyr-NHS on the surface of the graphene foam in sufficient quantity for it to serve as a suitable linker for the immobilisation of the enzyme glucose dehydrogenase (GDH) on the electrode. Evidence of this immobilisation was provided through electrochemical characterisation, before demonstrating an active enzyme response from GDH via the mediated oxidation of glucose at the electrode surface. A proportional relationship between the concentration of glucose and the peak anodic current from the redox mediator p-aminophenol led to the determination of a high sensitivity of 22.7 µA/mM/cm2 and a limit of detection of 5.25 µM. Such a result confirms the viability of these functionalised graphene foam electrodes as a metal-free high-performing anode within miniaturised, glucose-based biocatalytic devices, including enzymatic biofuel cells and biosensors. [ABSTRACT FROM AUTHOR]

• rGO supported CuO nanoparticles modified electrode was fabricated. • XRD, FTIR, SEM and edx confrmed the CuO@rGO composite. • The designed electrode acted as sensor for food dyes detection. Synthetic dyes are illegally used in foodstuffs and cause serious health issues in humans due to their carcinogenic nature. To avoid serious health issues, it is compulsory to detect and remove even the minute quantities of these harmful dyes in foodstuffs. Electrochemical sensors are accredited as an efficient and promising platform for the robust and sensitive determination of food toxins in various foodstuffs. Therefore, an efficient, facile, and competent sensor is devised for the simultaneous detection of Orange II (OR II) and Rhodamine B (RhB) supported by rGO and CuO nanoparticles. The synergism between rGO's immense surface area and the adsorption properties of CuO enhances selectivity and response time for the detection of OR II and RhB. This work elaborated the synthesis, characterization, and electrochemical behavior of CuO@3DGr electrode towards simultaneous sensing of OR II and RhB. Physicochemical techniques were utilized to validate the fabrication of targeted material. On the other hand, the electrochemical features of the developed sensor were characterized by cyclic voltammetry (CV) and electron impedance spectroscopy (EIS). Differential pulse voltammetry technique was employed to detect simultaneously Orange II and Rhodamine B on the surface of bare (GCE), GO/GCE, CuO/GCE, and CuO@3DGr/GCE. Multi-analyte detection is possible with DPV, a sensitive electrochemical method. Based on each toxin's specific electrochemical signature, the sensor may generate separate peaks by delivering a sequence of potential pulses and detecting the ensuing current. The parameters which influence the performance of the modified sensor were carefully evaluated. Under ambient conditions, the developed sensor exhibited excellent electrocatalytic activity in oxidation at 0.67 V of OR II and 0.96 V RhB with a low limit of detection 08 nM for OR II and 4.5 nM for RhB in Britton- Robinson buffer (BRB pH:7). The described methodology allowed a robust and fast analysis of food toxins in different foodstuff establishing this sensor as a novel tool for detecting food toxins. Tap water was used to analyze the practical applicability of developed electrode material and suitable results were achieved. These results showed that the as-synthesized novel electrochemical sensor has the potential for ultrasensitive determination and detection of toxins in different foodstuffs. [ABSTRACT FROM AUTHOR]

Nowadays, cancer is increasingly becoming one of the foremost threats to human being life worldwide, and diagnosing this deadly disease is one of the major priorities of researchers. Described as a monolayer-thin-sheet of hexagonally patterned carbon atoms, 'graphene' is considered an innovative evergreen carbon material ideal for a wide array of sensing applications and nanotechnologies. Graphene-based materials (GBMs) have acquired a huge share of interest in the scope of biosensor fabrication for early and accurate cancer diagnosis. Herein, we have insights reviewed the various routes and technologies for synthesized graphene, and GBMs including 3D graphene (i.e. hydrogels, foams, sponges and porous) and 0D graphene (i.e. quantum dots). Moreover, we have introduced the different types of graphene/GBMs biosensors (i.e. electrochemical biosensors, optical biosensors, field-effect transistors biosensors, electrochemiluminescence biosensors and microfluidics biosensors) and their merits and applications for cancer pre-stage detection. [ABSTRACT FROM AUTHOR]