Scalable Synthesis Approach Research Articles

Enhanced Oxidation‐Resistant and Conductivity in MXene Films with Seamless Heterostructure

AbstractMXene‐based films have garnered significant attention for their remarkable electrical and mechanical properties. Nevertheless, the practical application of MXene is impeded by its intrinsic instability caused by spontaneous oxidation. The traditional anti‐oxidative strategies frequently lead to a compromise in stability, electrical conductivity, and mechanical properties. In this study, a novel approach is proposed involving metal nano‐armoring, wherein a copper layer with nano thickness is deposited onto MXene film surfaces to establish a uniform and seamless heterogeneous interface (MXene@Cu). The precise tunability and uniformity of this heterostructure are consistently demonstrated through both theoretical calculations and experimental results. The MXene@Cu films exhibit exceptional electrical conductivity of 1.17 × 106 S m−1, electromagnetic interference shielding effectiveness of 77.1 dB, and tensile strength of 43.4 MPa. More importantly, this heterostructure significantly improves MXene's stability against oxidation. After exposure to air for 30 days, the resultant MXene@Cu films exhibit a remarkable conductivity retention of 72.0%, significantly exceeding that of pristine MXene films (44.3%). This scalable synthesis approach holds significant promise for electronic device applications, particularly in electromagnetic shielding and thermal management.

Continuous and Scalable Synthesis of Prussian Blue Analogues with Tunable Structure and Composition in Surfactant-Free Microreactor for Stable Zinc-Ion Storage.

We represent a segmented flow surfactant-free microfluidic strategy for continuous synthesis of Prussian blue analogues (PBAs) with high dispersity and high crystallization. Representative zinc hexacyanoferrate (ZnHCF) nanocubes were successfully synthesized in a microfluidic reactor within a few minutes via the cooperation method and possessed lower contents of crystal water and Fe(CN)6 3- vacancies than that of synthesis in bulk solution. The nucleation and particle growth process can be precisely controlled by the exploration of different flow rates and reaction temperatures during the formation of ZnHCF nanocubes in segmented flow microfluidic reactors. High crystallinity, low crystal water and vacancies in the ZnHCF structure were presented at relatively high temperatures for the crystal growth process. High-quality ZnHCF with a low content of crystal water showed excellent electrochemical activity and stability towards zinc-ion storage. The continuous and scalable synthesis approach can be extended to the fabrication of other PBAs such as NiHCF, CoHCF, MnHCF, and CuHCF with high dispersity without using any surfactants. The controllable construction of PBAs with tunable properties in microfluidic reactors provides a promising direction to minimize the gap between commercial reality and laboratory research.

Plasma-assisted fabrication of ultra-dispersed copper oxides in and on C-rich carbon nitride as functional composites for the oxygen evolution reaction.

Significant efforts have been continuously devoted to the mastering of green catalysts for the oxygen evolution reaction (OER), whose sluggish kinetics prevents a broad market penetration of water splitting as a sustainable route for large-scale hydrogen production. In this extensive scenario, carbon nitride (CN)-based systems are in focus thanks to their favorable characteristics, and, whereas graphitic CN has been largely investigated, the potential of amorphous carbon nitride (a-CNx) systems remains almost entirely unexplored. In this regard, our study presents a novel two-step plasma-assisted route to a-CNx systems comprising ultra-dispersed, i.e. "quasi-atomic" CuxO (x = 1, 2). The target materials were fabricated using an original strategy consisting in the magnetron sputtering of a-CNx on conducting glasses at room temperature, followed by functionalization with low CuxO amounts by radio frequency (RF)-sputtering, and final annealing under an inert atmosphere. The tailoring of the CuxO co-catalyst content and spatial dispersion, as well as the overall composite features as a function of preparative conditions, enabled a direct modulation of the resulting OER performances, rationalized based on the formation of p-n CuxO/a-CNx heterojunctions. The amenable and scalable synthesis approach underscores the practicality of this method to develop (photo)electrocatalysts synergistically integrating the advantages of both constituents, yielding low-cost, green, and stable functional platforms that could contribute to the broader adoption of sustainable energy solutions.

Rational Design of Fe-Based Layered Double Hydroxide for Water Oxidation: Molecular and Cationic Engineering

Nowadays, in the field of electrocatalysts for the oxygen evolution reaction, Fe-based LDHs stand out as one of the best oxygen evolution reactions (OER) electrocatalysts in alkaline conditions. In the attempt to improve the electrochemical performance of Fe-LDHs-based electrodes, many approaches have been reported.[1] Beyond these, interlayer space, Fe-clustering and covalent functionalization have been not explored, being the last two synthetic challenges within the field of LDHs.On the one hand, to explore the influence of interlayer space in the behaviour of Fe–LDHs as an oxygen evolution reaction (OER) electrocatalyst, we develop a family of NiFe-LDHs with the same metal composition, morphology, and dimensions and different alkyl sulfate to reach extreme ranges of basal spacing (from 8 to 32 Å). Increasing the basal space of the LDH results in a higher electrochemical surface area and a reduction of the resistance related to the chemisorption of oxygen leading to better kinetic behaviour. Indeed, the Tafel slope for the NiFe–LDHs with the highest basal space studied is similar to that obtained for exfoliated NiFe nanosheets and shows better stability as a consequence of the tridimensional robustness of the hybrid material.[2]On the other hand, to shed light on the influence of Fe-clustering on the OER performance, firstly, we have selected MgFe-based LDHs phases as model systems. By optimization of a hydrothermal method based on triethanolamine different Fe-clustering degree has been achieved, and thanks to the diamagnetic behaviour of Mg, a simple magnetic characterisation allows us to identify the Fe-clustering degree. Nevertheless, both samples behave identically in terms of OER performance when glassy carbon electrodes are used. Surprisingly, striking differences arise when the samples are tested on nickel foam. Specifically, the sample exhibiting the lower Fe-clustering behaves as a better electrocatalyst with a reduction of the overpotential values of more than 50 mV to reach 100 mA/cm2, as a consequence of a favoured surface transformation of MgFe-LDHs phases into more reactive oxyhydroxide NiFe-based ones during the electrochemical tests. [3] To extend our study to NiFe-LDH, we have successfully synthesized high-clustering nanometric NiFe-LDHs using a scalable synthesis approach. This synthetic protocol has allowed us to obtain a significantly higher concentration of approximately 100 g/L of our materials, which is almost two orders of magnitude larger than current state-of-the-art synthetic methods. Importantly, the Fe-clustering of this scale-up NiFe-LDH results in improved electrochemical performance compared to traditionally synthesized NiFe-LDH/FeOOH across various current density ranges and different electrochemical setups, including rotatory disk electrode (RDE) and Anion Exchange Membrane Water Electrolyzer (AEMWE), with testing conducted up to a current density of 3 A·cm-2. For instance, the overpotential at 2.5 A·cm-2 for the scale-up NiFe-LDHs is measured at 1.96 V, whereas the traditionally synthesized NiFe-LDH/FeOOH exhibit a higher overpotential of 2.18 V. [4]Last but not least, the covalent functionalization of LDHs has been explored to enhance their processability and stability as an electrocatalyst, for this, we develop for the first time the covalent functionalization of Fe-LDHs beyond silane-based molecules due to the reversible character of this bond in alkaline media. By a modified hydrothermal method from Kuroda et al. [5], the covalent functionalization of NiFe-LDHs with tris(hydroxymethyl) aminomethane (Tris) was performed. The NiFe-Tris LDH were fully characterized to identify the structural differences with a bare LDH. At the same time, the stability of the covalent functionalization in basic media was proved. Interestingly, the Tris molecule anchored to LDHs increases the electrocatalytic stability in absence of binder material. Thus, after 40 hours of the OER, the overpotential increase is 37% lower in the NiFe@Tris than in the NiFe-Cl@bare. To check the origin of this overpotential decrease, ICP analysis of electrolytes pre-treated with acid after the stability test was performed. A reduction of 27% and 17% of Ni and Fe respectively is observed in the electrolyte for functionalized samples. Consequently, it is demonstrated that, regardless of the decomposition process (detachment or dissolution), the NiFe-LDH functionalized presents greater stability.[6]Overall, we demonstrated that the rational design of LDHs can enhance catalytic activity and stability for their use as electrocatalysts for the oxygen evolution reaction.

MnF2 Surface Modulated Hollow Carbon Nanorods on Porous Carbon Nanofibers as Efficient Bi-Functional Oxygen Catalysis for Rechargeable Zinc-Air Batteries.

Developing highly efficient bi-functional noble-metal-free oxygen electrocatalysts with low-cost and scalable synthesis approach is challenging for zinc-air batteries (ZABs). Due to the flexible valence state of manganese, MnF2 is expected to provide efficient OER. However, its insulating properties may inhibit its OER process to a certain degree. Herein, during the process of converting the manganese source in the precursor of porous carbon nanofibers (PCNFs) to manganese fluoride, the manganese source is changed to manganese acetate, which allows PCNFs to grow a large number of hollow carbon nanorods (HCNRs). Meanwhile, manganese fluoride will transform from the aggregation state into uniformly dispersed MnF2 nanodots, thereby achieving highly efficient OER catalytic activity. Furthermore, the intrinsic ORR catalytic activity of the HCNRs/MnF2@PCNFs can be enhanced due to the charge modulation effect of MnF2 nanodots inside HCNR. In addition, the HCNRs stretched toward the liquid electrolyte can increase the capture capacity of dissolved oxygen and protect the inner MnF2, thereby enhancing the stability of HCNRs/MnF2@PCNFs for the oxygen electrocatalytic process. MnF2 surface-modulated HCNRs can strongly enhance ORR activity, and the uniformly dispersed MnF2 can also provide higher OER activity. Thus, the prepared HCNRs/MnF2@PCNFs obtain efficient bifunctional oxygen catalytic ability and high-performance rechargeable ZABs.

Just laser irradiation of silver benzoate water solution — A direct way of Ag nanofibers synthesis for broadband SERS detection

Highly efficient, homogeneous and reproducible substrates for surface enhanced Raman spectroscopy (SERS) are in high demand for practical broadband sensing and the detection of various analytes. The most promising SERS structures in terms of morphology are nanofibers, forming homogeneous coatings with broadband electric field enhancement. However, existing synthesis methods for the formation of nanofibers are multistage, requiring the preliminary synthesis of templates, using additional components, such as surfactants and capping agents, species extraction from the reaction mixture, washing and sedimentation onto a substrate. Here, we present a simple and scalable synthesis approach allowing the fabrication of long winding silver nanofibers directly on a substrate surface, without any additional stages. The process proposed is ecologically friendly and based on laser irradiation of a substrate–solution interface using a low intensity continuous wave unfocused laser beam with a wavelength of 448 nm. As the liquid phase, a silver benzoate water solution without any additional chemicals was used. The deposited nanofibers formed a continuous coating with an area corresponding to the laser beam, ca. 3 mm2, and were characterized by an enhancement factor as high as 107 in the broad spectral region, a low experimental detection limit of 10−11 M and high reproducibility of the SERS signal with a variation of ∼10%.

Large-Area Synthesis of Ferromagnetic Fe5- x GeTe2 /Graphene van der Waals Heterostructures with Curie Temperature above Room Temperature.

Van der Waals (vdW) heterostructures combining layered ferromagnets and other 2D crystals are promising building blocks for the realization of ultracompact devices with integrated magnetic, electronic, and optical functionalities. Their implementation in various technologies depends strongly on the development of a bottom-up scalable synthesis approach allowing for realizing highly uniform heterostructures with well-defined interfaces between different 2D-layered materials. It is also required that each material component of the heterostructure remains functional, which ideally includes ferromagnetic order above room temperature for 2D ferromagnets. Here, it is demonstrated that the large-area growth of Fe5- x GeTe2 /graphene heterostructures is achieved by vdW epitaxy of Fe5- x GeTe2 on epitaxial graphene. Structural characterization confirms the realization of a continuous vdW heterostructure film with a sharp interface between Fe5- x GeTe2 and graphene. Magnetic and transport studies reveal that the ferromagnetic order persists well above 300 K with a perpendicular magnetic anisotropy. In addition, epitaxial graphene on SiC(0001) continues to exhibit a high electronic quality. These results represent an important advance beyond nonscalable flake exfoliation and stacking methods, thus marking a crucial step toward the implementation of ferromagnetic 2D materials in practical applications.

Scalable Room-Temperature Synthesis of a Hydrogen-Sieving Zeolitic Membrane on a Polymeric Support

Synthesis of H2-sieving membranes for high-temperature applications is highly desired for improving the energy efficiency of H2 production from steam reforming and developing a low-cost solution for precombustion carbon capture. Zeolite-based membranes are ideal for this because they possess excellent hydrothermal stability. However, current methods to synthesize H2-sieving zeolite membranes rely on hydrothermal synthesis on expensive ceramic supports followed by postsynthetic functionalization to shrink the effective pore size. The scalable synthesis approach on a low-cost polymeric support implementable at room temperature is highly desired to advance applications based on H2-sieving membranes. Herein, we report the room-temperature fabrication of H2-sieving zeolitic membranes by simply assembling sodalite precursor, i.e., RUB-15 nanosheets, on a porous polybenzimidazole support. The presence of adsorbed surfactants on the nanosheets led to an entropically driven ordering of the nanosheets witnessed by a sharp (200) d-spacing peak by X-ray diffraction. The intersheet gap was successfully eliminated by the ion exchange of cationic surfactants by a diluted acetic acid solution. The resulting zeolitic films show attractive H2/CO2 and H2/CH4 separation performances at elevated temperatures. The fabrication of H2-sieving zeolitic membranes without resorting to hydrothermal synthesis or high-temperature activation is expected to push the efforts to scale up zeolite membranes for application in gas separation and membrane reactors.

Construction of indigenous tin incorporated nickel dichalcogenide nanosheets for high energy all solid-state hybrid supercapacitor

Despite solid-state energy storage devices are one of the potential candidates for modern electronics, it usually suffers from poor compatibility with gel electrolyte acquiring insufficient energy density. Continuous efforts have been devoted to overcome the energy density paucity. Here, we highlight the strategy to augment the energy density of solid-state electrochemical energy storage device by constructing indigenous Sn doped nickel dichalcogenides nanosheets along with tunable composition. Micrometre size, flat nanosheets offer high compatibility to the gel electrolyte and their porous structure grant multi directional active site access. Modified electronic structure upon cation/anion substitution gain enhanced charge transfer and increased numbers of active sites. Cooperative features of nanostructures and controlled doping, boosted the specific capacity of samples from 134 to 437 mAh/g with remarkable rate retention of 42–81%. Prepared range of anion/cation/cation & anion doped nickel dichalcogenides, i.e., NiSSe, Ni0.66Sn0.33S2 and Ni0.66Sn0.33SSe further gain benefit upon coupling with freshly prepared N, S doped bio-derived carbon (OP-850). Resultant, all solid-state energy storage devices delivered 54, 78 and 127 mAh/g cell capacity at 3 A/g with outstanding energy density of 54, 78 and 102 Wh/kg, respectively. These comparative interpretations confer, Ni0.66 Sn0.33SSe//N, S doped OP-850 must be the promising all solid-state energy storage device with exceptional energy density outcome. Excellent cycle stability and LED pattern illumination demonstrate the feasibility of the device. Furthermore, such simple scalable synthesis approach could also extend to prepare other doped metal chalcogenides nanosheets, likely achieve breakthroughs in various applications.

Scalable synthesis of Cu clusters for remarkable selectivity control of intermediates in consecutive hydrogenation

Subnanometric Cu clusters that contain only a small number of atoms exhibit unique and, often, unexpected catalytic behaviors compared with Cu nanoparticles and single atoms. However, due to the high mobility of Cu species, scalable synthesis of stable Cu clusters is still a major challenge. Herein, we report a facile and practical approach for scalable synthesis of stable supported Cu cluster catalysts. This method involves the atomic diffusion of Cu from the supported Cu nanoparticles to CeO2 at a low temperature of 200 °C to form stable Cu clusters with tailored sizes. Strikingly, these Cu clusters exhibit high yield of intermediate product (95%) in consecutive hydrogenation reactions due to their balanced adsorption of the intermediate product and dissociation of H2. The scalable synthesis strategy reported here makes the stable Cu cluster catalysts one step closer to practical semi-hydrogenation applications.

Rationalizing nitrogen-doped secondary carbon particles for practical lithium-sulfur batteries

Nanostructured carbon host materials are widely used to improve both sulfur utilization rate and reaction kinetics in lithium-sulfur (Li-S) batteries. However, high complexity/cost of materials synthesis and difficulty in processing nano-materials into high-mass-loading electrodes are still significant barriers to the development of low-cost and high-energy Li-S batteries. In this study, we reported a generic and scalable synthesis approach to prepare nitrogen-doped secondary carbon particles. By using nitrogen-containing precursor as an integration reagent, the nanosized Ketjen Black particles were integrated into micron-size secondary ones and nitrogen-doped (NKB) simultaneously through a one-step heat treatment. With NKB as an example material, the effects of particle integration degree on the secondary particles’ structures, pore volume and connectivity, sulfur loading capability, and cell performance were studied and discussed. At an optimal integration condition, the NKB particles had significantly improved particle dimensions with well-maintained high specific surface area and pore volume. Contributed by the micron size and high pore volume, the NKB/S were successfully used for high-sulfur-loading cathode coating (4–7 mgs cm−2) and were able to deliver a specific capacity of ∼1100 mAh g−1 at a practical low-porosity (50 %) and lean-electrolyte conditions (E/S =4 µL mg−1). Feasibility of the materials for practical use was validated through scaling up synthesis (40 g/batch), large-area electrode coating, and practical pouch cell (1.6 Ah) assembly and test.

Facile solid-state synthesis of tetragonal CuFe2O4 spinels with improved infrared radiation performance

Spinel materials are gradually becoming promising materials for high infrared emissivity owing to their unique crystal structure. However, the facile low-temperature solid-state synthesis of infrared radiation materials with superior emissivity remains a tremendous challenge. Herein, a general and simple approach for scalable synthesis of CuFe2O4 samples with spinel structure at low temperatures is smartly developed. The optimal experimental conditions for the infrared emissivity of CuFe2O4 are obtained by the detailed investigation into experimental parameters including calcination temperatures, heating rates, and the mass of polyvinyl pyrrolidone. Under the optimal experimental conditions, the infrared emission values of CuFe2O4 in the wavelength range of 3–5 μm can be as high as 0.986. More significantly, the work here will provide significant guidance for the efficient preparation of spinel materials with excellent infrared emissivity, especially at low temperatures.

PtCo Nanoalloy Co-Doped Atomically Dispersed Co-N4 Catalyst for Oxygen Reduction in Fuel Cell

Fuel cells are the trending renewable energy source for sustainable future; however, the insufficient performance of Pt-based cathode catalysts particularly, the limited durability hampers their broader applications. Recently, Pt nanoalloys and transition metal-based single-atom catalysts have been emerging catalysts for ORR in fuel cells. However, the high cost of the Pt group metals (PGM) and the limited performance of non-PGM catalysts are huge challenges to meet the desired performance of the fuel cells. Here we report a PtCo nanoalloy catalyst encased by the atomically dispersed Co-N4 doped graphitic carbon nanosheets for the oxygen reduction reaction. The catalyst is prepared by a facile molten salt synthesis method to confine PtCo nanoalloy into atomically dispersed Co and nitrogen co-doped graphitic carbon nanosheets through high-temperature annealing. The catalyst is a unique combination of PtCo nanoparticles and atomically dispersed Co-N4 in a modified carbon nanosheets matrix which endows a synergistic response leading to a high oxygen reduction activity and stability. The as-prepared PtCo@gCNS nanoparticles along with atomically dispersed Co-N4 active sites possess remarkable oxygen reduction performance demonstrating a mass activity of 1.268 AmgPt -1 and superior durability with a negligible decay after 30000 potential cycles. Density functional theory calculations reveal the richly accessible PtCo nanoalloy and atomically dispersed Co-N/C in the ultra-thin graphitic carbon nanosheets as dual active sites responsible for the improved ORR performance. Moreover, ultra-thin graphitic carbon nanosheets provide enhanced electronic conductivity and mass transport, while carbon-coated architecture provides improved durability against catalyst nanoparticles dissolution. Such a unique and multi-components catalyst system with PtCo nanoalloy, Co-N4 single atomic sites and upgraded carbon support altogether provide an effective ORR catalyst. The synergistic catalysis resulting from the atomically dispersed Co-N4 single atomic sites and PtCo nanoparticles engrossed in graphitic carbon nanosheets through a facile and scalable synthesis approach could step up the realistic applications of oxygen electrocatalysts in practical fuel cells. Figure 1

Development of novel blue emissive carbon dots for sensitive detection of dual metal ions and their potential applications in bioimaging and chelation therapy

In recent years, there has been an increased interest in the use of fluorescent carbon dots (C-dots) as an alternative to toxic synthetic organic dyes in live cell imaging, medical diagnostics and other diverse biomedical applications. In the present work, highly fluorescent C-dots have been prepared from commercially available peptic digest of animal tissue, without using any additional chemical reagent for surface functionalization. The synthesized C-dots are monodispersed nanomaterials with hydroxyl, carboxyl and amino surface functionalities and remain stable in high ionic strength media and over a wide range of pH. They exhibit a strong blue fluorescence upon excitation at 350 nm with a high quantum yield of 61%. The potential use of these C-dots as fluorescent nanoprobe for specific metal ions (Cu2+ and Hg2+) detection through chelation, radical scavenging and cellular imaging has been investigated. These highly fluorescent labels show rapid cellular internalization without hampering cellular integrity. Cell proliferation assay demonstrates that these C-dots have minimal cell toxicity even at a high concentration of 3 mg/mL. They show significant quenching on incubation with cells pretreated with Cu2+ and Hg2+ ions. They also show rapid exocytosis from cells showcasing their high potential for chelation therapy. Thus, this study offers a scalable synthesis approach for highly fluorescent and bio-compatible C-dots from a cost-effective precursor, which can be used for specific metal ions detection and their removal from cells through chelation via exocytosis. They can also be used as an alternate to synthetic organic dyes for fluorescence-based cell-imaging.

A Green and Scalable Synthesis of Na3 Fe2 (PO4 )P2 O7 /rGO Cathode for High-Rate and Long-Life Sodium-Ion Batteries.

Sodium-ion battery has been considered as one of the most promising power sources for large-scale energy storage systems due to its similar electrochemistry to the lithium-ion battery and the crust abundance of Na resources. Essentially, developing low-cost electrode materials along with a facile and economical synthesis procedure is critically important to promote the commercialization of sodium-ion batteries. However, applicable cathode materials capable of being massively produced are still scarcely reported to date. Herein, a green and scalable synthesis approach is developed to obtain Na3 Fe2 (PO4 )P2 O7 (NFPP)/rGO composite by using FePO4 and Na3 PO4 as the resources, during which all the atoms present in the starting materials end up in the product. The prepared Na3 Fe2 (PO4 )P2 O7 /rGO cathode exhibits an ultralong cycle life (capacity retention of 72.4% after 8000 cycles at 20 C) and outstanding rate capability (42.4 mAh g-1 at 100 C). In particular, the NFPP/rGO-HC full battery assembled by the Na3 Fe2 (PO4 )P2 O7 /rGO cathode and hard carbon anode demonstrates an energy density of 192Wh kg-1 and superior cycling performance (capacity retention of 85.2% after 500 cycles). These results will contribute to the development of sodium-ion batteries from applicable Na3 Fe2 (PO4 )P2 O7 /rGO cathode material.

A simple, rapid and scalable synthesis approach for ultra-small size transition metal selenides with efficient water oxidation performance

A simple, rapid and scalable microwave method for preparing ultra-small size transition metal selenides to boost water oxidation.

Nitrogen-doped nanoporous graphene induced by a multiple confinement strategy for membrane separation of rare earth.

SummaryRare earth separation is still a major challenge in membrane science. Nitrogen-doped nanoporous graphene (NDNG) is a promising material for membrane separation, but it has not yet been tested for rare earth separation, and it is limited by multi-complex synthesis. Herein, we developed a one-step, facile, and scalable approach to synthesize NDNG with tunable pore size and controlled nitrogen content using confinement combustion. Nanoporous hydrotalcite from Zn(NO3)2 is formed between layers of graphene oxide (GO) absorbed with phenylalanine via confinement growth, thus preparing the sandwich hydrotalcite/phenylalanine/GO composites. Subsequently, area-confinement combustion of hydrotalcite nanopores is used to etch graphene nanopores, and the hydrotalcite interlayer as a closed flat nanoreactor induces two-dimensional space confinement doping of planar nitrogen into graphene. The membrane prepared by NDNG achieves separation of Sc3+ from the other rare earth ions with excellent selectivity (∼3.7) through selective electrostatic interactions of pyrrolic-N, and separation selectivity of ∼1.7 for Tm3+/Sm3+.

Effective synthesis route of renewable nanoporous carbon adsorbent for high energy gas storage and CO2/N2 selectivity

Mandarin peels are fruit by-products and provide an economically viable and renewable carbon source. In order to recycle and convert the bio-waste materials, a scalable synthesis approach for mandarin peel-derived porous and activated carbon were designed, and an influence of its preparation conditions such as carbonization, activation temperatures and activating agents was well investigated. The developed nanoporous carbon achieves high textural properties of surface area of ∼2500 m 2 g −1 and pore volume of 1.04 cm 3 g −1 and is naturally doped by sulphur. Owing to a high textural properties and some metal residues, obtained nanoporous carbon exhibited promising sorption properties for all energy carrier gases (e.g. H 2 , CH 4 ) and excellent CO 2 separation and storage performance, that to the best of our knowledge are among the highest reported values for porous carbons. The H 2 storage capacities at 77 and 298 K and 25 bar were recorded as 6.1 and 0.45 wt%, respectively. For CH 4 and CO 2 storage at 298 K and 25 bar, uptake of 9.65 and 20.6 mmol g −1 were achieved, respectively. Additionally, the separation of various binary mixtures (CO 2 /CH 4 , CH 4 /N 2 and CO 2 /N 2 ) at different composition was studied according to the ideal adsorbed solution theory (IAST) model and a high value of 63 was achieved for CO 2 /N 2 which is among the top values for nanoporous carbons reported in the literature. • Scalable synthesis approach for mandarin peel-derived porous and activated carbon was developed. • The optimal conditions for the preparation of mandarin peel-derived AC were determined. • One of the highest storage capacities of energy carriers (H 2 and CH 4 ) and greenhouse gas (CO 2 ) were achieved. • Developed AC achieved highest CO 2 /N 2 selectivity of 63.

Polyaspartic Acid-Derived Micro-/Mesoporous Carbon for Ultrahigh H2 and CH4 Adsorption.

A poly(amino acid)-based approach for scalable synthesis of micro-/mesoporous carbon (PC) with high specific surface area and narrow distribution of micro- and mesopores is presented. Using cross-linked poly aspartic acid as a precursor, PC was obtained by in situ one-step carbonization without the activating agent. The resulting PC had an ultrahigh adsorption capacity for H2 (4.43 wt %) and CH4 (4.49 mmol g–1). This novel method could significantly decrease the wastewater hazards caused by washout of the considerable amount of the activating agent. The PC showed promising application in gas adsorption and storage.

Macroporous Cu(OH)2 nanorod network fabricated directly on Cu foil as binder-free Lithium-ion battery anode with ultrahigh capacity

Metal-hydroxide based materials have attracted much attention as electrode materials for electrochemical energy storage and conversion owing to their unique large interlayer spacing, enhanced active surface area and robustness that can result in high electrochemical performance. Here, we report on the synthesis of a macroporous Cu(OH)2 nanorod network via single-step surface chemical oxidation and demonstrate its impressive Li ion battery (LIB) performance as a binder-free anode material. The Cu(OH)2 nanorod network anode delivers an ultrahigh reversible discharge capacity of 2145 mAhg−1 at a current density of 0.1 Ag−1 in the first cycle that then stabilizes at 1472 mAhg−1 in the subsequent cycles. The excellent rate performance at the ultrahigh current rates of 1.0 and 2.0 Ag−1 with a Coulombic efficiency of 99% was obtained. The electrode exhibits the capacity of 506 mAhg−1 even after 100 cycles which is higher than the conventional carbonaceous materials. Our experimental findings and scalable synthesis approach can be useful for developing other free-standing binder-free transition metal hydroxide materials that can be directly used as battery electrodes and catalysts.