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The paper considers the possibility of using the diamond-silicon carbide composite Skeleton ® with a technological coating of polycrystalline silicon as a substrate for X-ray mirrors used with powerful synchrotron radiation sources (third+ and fourth generation). Samples were studied after polishing to provide the following surface parameters: root-mean-square flatness ≃ 50 nm, micro-roughness on the frame 2 µm × 2 µm σ ≃ 0.15 nm. The heat capacity, thermal conductivity and coefficient of linear thermal expansion were investigated. For comparison, a monocrystalline silicon sample was studied under the same conditions using the same methods. The value of the coefficient of linear thermal expansion turned out to be higher than that of monocrystalline silicon and amounted to 4.3 × 10 -6  K -1 , and the values of thermal conductivity (5.0 W cm -1  K -1 ) and heat capacity (1.2 J K -1  g -1 ) also exceeded the values for Si. Thermally induced deformations of both Skeleton ® and monocrystalline silicon samples under irradiation with a CO 2 laser beam have also been experimentally studied. Taking into account the obtained thermophysical constants, the calculation of thermally induced deformation under irradiation with hard (20 keV) X-rays showed almost three times less deformation of the Skeleton ® sample than of the monocrystalline silicon sample., (open access.)

A series of metal- and silica-containing carbon-based nanocomposites were synthesized by pyrolysis of a resorcinol-formaldehyde polymer modified with metal oxide/silica nanocomposites (MxOy/SiO 2 , where M = Mg, Mn, Ni, Cu and Zn) via the thermal oxidative destruction of metal acetates adsorbed on highly dispersed silica (A380). The concentration of metals was 3.0 mmol/g SiO 2 . The phase composition and morphological, structural and textural properties of the carbon materials were analyzed by X-ray diffraction, SEM, Raman spectroscopy and low-temperature N 2 adsorption. Thermal decomposition under a nitrogen atmosphere and in air was analyzed using TG-FTIR and TG-DTG-DSC techniques to determine the influence of the filler on the decomposition process. The synthesized composites show mesoporous structures with high porosity and narrow pore size distributions. It could be shown that the textural properties and the final composition of the nanocomposites depend on the metal oxide fillers of the precursors. The data obtained show that nickel and copper promote the degree of graphitization and a structural order with the highest porosity and largest specific surface area of the hybrid composites. The good adsorption properties of the obtained materials were shown for the recovery of p-chlorophenol and p-nitrophenol from aqueous solutions.

With the advent of wireless technology, magnetic-carbon composites with strong electromagnetic wave (EMW) absorption capability in low-/middle-frequency range are highly desirable. However, it remains challenging for rational construction of such absorbers bearing multiple magnetic components that show uniform distribution and favorable magnetic loss. Herein, a facile metal-oxo cluster (MOC) precursor strategy is presented to produce high-efficiency magnetic carbon composites. Nanosized MOC Fe 15 shelled with organic ligands is employed as a novel magnetic precursor, thus allowing in situ formation and uniform deposition of multicomponent magnetic Fe/Fe 3 O 4 @Fe 3 C and Fe/Fe 3 O 4 nanoparticles on graphene oxides (GOs) and carbon nanotubes (CNTs), respectively. Owing to the good dispersity and efficient magnetic-dielectric synergy, quaternary Fe/Fe 3 O 4 @Fe 3 C-GO exhibits strong low-frequency absorption with RL min of -53.5 dB at C-band and absorption bandwidth covering 3.44 GHz, while ultrahigh RL min of -73.2 dB is achieved at X-band for ternary Fe/Fe 3 O 4 -CNT. The high performance for quaternary and ternary composites is further supported by the optimal specific EMW absorption performance (-15.7 dB mm -1 and -31.8 dB mm -1 ) and radar cross-section reduction (21.72 dB m 2 and 34.37 dB m 2 ). This work provides a new avenue for developing lightweight low-/middle-frequency EMW absorbers, and will inspire the investigation of more advanced EMW absorbers with multiple magnetic components and regulated microstructures., (© 2023 Wiley‐VCH GmbH.)

A series of carbon composites were synthesised by carbonisation of resorcinol-formaldehyde resin mixtures with the addition of different amounts of sodium alginate (SA) and compared with a composite prepared using Na 2 CO 3 as a catalyst for the polymerisation reaction. The effect of operating parameters such as SA concentration and polycondensation time on the structural and morphological properties of resorcinol-formaldehyde resins (RFR) and carbon-derived composites was investigated for further use as adsorbents. The synthesised composites were characterised by FTIR, SEM, Raman spectroscopy and N 2 adsorption/desorption techniques. It was found that the morphology, specific surface area (S BET ~347-559 m 2 /g), volume and particle size distribution (~0.5-4 μm) and porosity (V por =0.178-0.348 cm 3 /g) of the composites were influenced by the concentration of SA and the synthesis technique and determined the adsorption properties of the materials. It was found that the surface of the filled chars was found to have an affinity for heavy metals and has the ability to form chemical bonds with cadmium ions. The maximum sorption capacities for Cd(II), i. e. 13.28 mg/g, were observed for the sample synthesised with the highest SA content. This confirms the statement that as-synthesised materials are promising adsorbents for environmental applications., (© 2023 Wiley-VCH GmbH.)

This study evaluates the removal of several dyes with different charge properties, i.e., anionic (Acid Red 88), cationic (Basic Red 13), and neutral (Basic Red 5) using transition metal-doped TiO 2 supported on a high-surface-area activated carbon. Experimental results confirm the successful deposition of TiO 2 and the derivatives (Zr-, Cu-, and Ce-doped samples) on the surface of the activated carbon material and the development of extended heterojunctions with improved electronic properties. Incorporating a small percentage of dopants significantly improves the adsorption properties of the composites towards the three dyes evaluated, preferentially for sample AC/TiO 2 _Zr. Similarly, the photodegradation efficiency highly depends on the nature of the composite evaluated and the characteristics of the dye. Sample AC/TiO 2 _Zr demonstrates the best overall removal efficiency for Acid Red 88 and Basic Red 5-83% and 63%, respectively. This promising performance must simultaneously be attributed to a dual mechanism, i.e., adsorption and photodegradation. Notably, the AC/TiO 2 _Ce outperformed the other catalysts in eliminating Basic Red 13 (74%/6 h). A possible Acid Red 88 degradation mechanism using AC/TiO 2 _Zr was proposed. This study shows that the removal efficiency of AC/TiO 2 composites strongly depends on both the material and pollutant.

Co-based coordination polymers (CoCP) based on 4,4'-bis(1H-benzo[d]imidazol-1-yl)-1,1'-biphenyl (BMB) ligand have been synthesized for the first time by the solvothermal method. The CoCP was carbonized at 700 °C under a nitrogen atmosphere to obtain carbide coordination polymer (C-CoCP) with a unique two-dimensional layered network structure. C-CoCP@GO was obtained by binding with GO and C-CoCP, its morphology and structure were investigated by XRD, SEM, EDS, FTIR, and TGA, which confirmed its two-dimensional stacked layered structure with high catalytic activity and large specific surface area. A highly sensitive electrochemical sensor was constructed for the simultaneous detection of hydroquinone and catechol based on the prepared carbon-based composite. Under optimized conditions, the working potentials (vs. Ag/AgCl) of HQ and CC are at 0.097 V and 0.213 V, respectively. The sensor exhibited an extremely wide linear range of 3-600 μM and 3-1750 μM for hydroquinone (HQ) and catechol (CC), respectively, with limits of detection (LOD) of 0.46 μM and 0.27 μM. The electrode material demonstrated stability over 14 days without significant attenuation of the response signal. Impressively, the sensor shows high stability, reproducibility, and selectivity due to the stable carbon skeleton structure of the C-CoCP material. In addition, it can be applied to the detection of hydroquinone in real samples with high interference immunity and high recovery. Hence, the C-CoCP@GO composite proved to be a great prospect and highly sensitive sensing platform for the detection of phenolic isomers., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Biomass exploitation is a global trend due to the circular economy and the environmentally friendly spirit. Numerous applications are now based on the use of biomass-derived products. Hydrogen sulfide (H 2 S) is a highly toxic and environmentally hazardous gas which is emitted from various processes. Thus, the efficient removal of this toxic hazardous gas following cost-effective processes is an essential requirement. In this study, we present the synthesis and characterization of biomass-derived activated carbon/zinc oxide (ZnO@AC) composites from different biomass sources as potential candidates for H 2 S sorption. The synthesis involved a facile method for activated carbon production via pyrolysis and chemical activation of biomass precursors (spent coffee, Aloe-Vera waste leaves, and corncob). Activated carbon production was followed by the incorporation of zinc oxide nanoparticles into the porous carbon matrix using a simple melt impregnation method. The synthesized ZnO@AC composites were characterized using X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and nitrogen porosimetry. The H 2 S removal performance of the ZnO@AC composites was evaluated through sorption experiments using a handmade apparatus. Our findings demonstrate that the Aloe-Vera-, spent coffee-, and corncob-derived composites exhibit superior H 2 S sorption capacity up to 106 mg H2S /g ads. , 66 mg H2S /g ads. , and 47 mg H2S /g ads. , respectively.

Sodium iron phosphate-pyrophosphate, Na 4 Fe 3 (PO 4 ) 2 P 2 O 7 (NFPP) emerges as an excellent cathode material for sodium-ion batteries. Because of lower electronic conductivity, its electrochemical performance depends drastically on the synthesis method. Herein, we provide a simple and unified method for synthesis of composites between NFPP and reduced graphene oxide (rGO) and standard carbon black, designed as electrode materials for both sodium- and lithium-ion batteries. The carbon additives affect only the morphology and textural properties of the composites. The performance of composites in sodium and lithium cells is evaluated at elevated temperatures. It is found that NFPP/rGO outperforms NFPP/C in both Na and Li storage due to its hybrid mechanism of energy storage. In sodium half-cells, NFPP/rGO delivers a reversible capacity of 95 mAh/g at 20 °C and 115 mAh/g at 40 °C with a cycling stability of 95% and 88% at a rate of C/2. In lithium half-cells, the capacity reaches a value of 120 mAh/g at 20 and 40 °C, but the cycling stability becomes worse, especially at 40 °C. The electrochemical performance is discussed on the basis of ex situ XRD and microscopic studies. The good Na storage performance of NFPP/rGO at an elevated temperature represents a first step towards its commercialization.

Nowadays, carbon-based nano-structured materials are widely preferred for composite coating as anti-corrosive reinforcement mainly due to its enhanced physical, chemical and mechanical properties. Herein we develop highly efficient Graphitic carbon nitride-Silica-Titania (gC 3 N 4 /SiO 2 /TiO 2 ) ternary nanocomposite are synthesized and it is used as a nanofillers in the corrosive protection layer on the proposed metal specimen (i.e., mild steel specimen) in an aggressive chloride environment. Size, structural and morphological analysis were analysed for the confirmation of presence of particles. gC 3 N 4 is currently earning quite drastic attention, owing to its affordable cost compared to carbon nanotubes and other carbon-based materials, when gC 3 N 4 incorporated with SiO 2 and TiO 2 , the composite matrix greatly improves the mechanical strength of the coating mixture. XRD, XPS, EDS analysis projects excellent formation and presence of the ternary nanocomposites. The particles are well-dispersed in epoxy and organic resin and deposited on the mildsteel panels and it is examined using various surface and structural characterization techniques. The obtained results are very encouraging and the ternary composite coatings can be recommended for real world applications., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Carbon materials with hierarchical morphologies, pores, and compositions have attracted extraordinary attention due to their unique structural advantages and widespread applications. However, their controllable synthesis remains a grand challenge. Herein, a solvent-mediated strategy was demonstrated for the preparation of an urchin-like superstructure via modulating the hydrothermal condition (acetic acid/water ratio) of metal-organic frameworks (MOFs). The direct pyrolysis of a hierarchical NUS-6 precursor produced a well-defined carbon-based composite consisting of sulfur-doped carbon (SC) and HfO 2 with an urchin-like morphology and micro-/mesoporosity, while the doped S sites and oxygen vacancies of HfO 2 can help to anchor and activate Pd nanoparticles (NPs) through the strong host-guest interaction, which was further confirmed by the calculated results of the binding energy and differential charge density through density functional theory (DFT). The synthesized Pd@SC/HfO 2 composite exhibited extremely high catalytic activity and stability toward the water-phase hydrodeoxygenation of vanillin (conversion >99%, selectivity >99%), as well as good universality for the hydrogenation of a series of unsaturated hydrocarbons in an aqueous system. Remarkably, the catalytic activity and structural stability of Pd@SC/HfO 2 were largely maintained even after successive 10 cycles.

Eutrophication is a widespread environmental challenge caused by excessive phosphate. Thus, wastewater engineers primarily aim to limit the phosphate concentration in water bodies. Layered double hydroxides (LDHs) are lamellar inorganic materials containing tunable brucite-like structures. This review discusses the fundamental aspects and latest developments in phosphate removal using LDH-based materials. Based on the divalent cations, Ca, Mg, and Zn-containing LDHs are largely used along with trivalent cations such as Al and Fe owing to their limited toxicities. However, classical LDHs are affected by the presence of co-existing anions, have a narrow working pH range, and have moderate adsorption capacities. Binary LDHs have been designed to be selective towards phosphate by the addition of a third metal such as Zr 4+ . Developing LDH composites with magnetic, polymeric or carbon materials are feasible approaches for increasing adsorption capacity, stability, and reusability of LDHs. Biochar as a carrier material for LDHs achieved remarkable phosphate adsorption performance and improved LDH dispersion, anion exchange capacity, and ease of separation. The use of recovered phosphate as an SRF, which is a type of bioavailable fertilizer, is a promising approach., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This work describes fabrication steps of the carbon composite based on molecular imprinted poly(methacrylic acid) (MIP-CC) as a new adsorbent for the selective removal of fenpiroxymate pesticide (Fen). The prepared composite was characterized using Brunauer-Emmett-Teller (BET), zeta sizer and Field Emission Scanning Electron Microscopy (FESEM) techniques. The influence of operational parameters such as solution pH, contact time, amount MIP for preparation of carbon composite and amount MIP- CC toward removal of Fen have been evaluated and optimized via central composite design (CCD) as an optimization tool of response surface method. The optimum removal (87%) was achieved at pH 6.5, 1.53 g/L carbon composite prepared with 3.4 wt % MIP at 70 min. The maximum adsorption of Fen by the fabricated MIP-CC was 254 mg/g. Compared with the corresponding non-imprinted polymer (NIP-CC), the MIP-CC exhibited higher adsorption capacity and outstanding selectivity toward Fen. Langmuir isotherm best fitted the adsorption equilibrium data of MIP-CC and the kinetics followed a pseudo-second-order model. The calculated thermodynamic parameters showed that adsorption of Fen pesticide was spontaneous and exothermic under the studied conditions.

The protection and regeneration of the water environment is currently one of the most critical concerns for the sustainable development of human society. To solve the water crisis, the use of capacitive deionization (CDI) technology to extract fresh-water that is suitable for human consumption from abundant surface-water is a feasible solution. In this work, a cobalt benzimidazole frameworks (ZIF-9) derived carbon composites with a unique quasi-microcubic morphology is synthesized and used the as-prepared materials as an electrode material for the CDI. Interestingly, the ZIF-9 derived carbon composites exhibit an impressive desalination capacity of 55.4 mg g -1 and can be reused. Measurements in surface-water (Beijing-Hangzhou Grand Canal, Slender West Lake, Initial rainwater, Rain water) show that this CDI technology based on ZIF-9 derived carbon composites not only has a strong adsorption effect on metal ions but also can remarkably kill microorganisms. The results show that the technology can effectively kill bacteria (Escherichia coli and Bacillus) and algae with 95% and 91.7% inhibition rates, respectively. This work provides a valuable example for the use of metal-organic framework-derived carbon composites as high-performance electrode materials of CDI and opens a new direction for promoting the application of CDI in surface-water., (© 2021 Wiley-VCH GmbH.)

This review paper presents the most recent research progress on carbon-based composite electrocatalysts for the oxygen evolution reaction (OER), which are of interest for application in low temperature water electrolyzers for hydrogen production. The reviewed materials are primarily investigated as active and stable replacements aimed at lowering the cost of the metal electrocatalysts in liquid alkaline electrolyzers as well as potential electrocatalysts for an emerging technology like alkaline exchange membrane (AEM) electrolyzers. Low temperature electrolyzer technologies are first briefly introduced and the challenges thereof are presented. The non-carbon electrocatalysts are briefly overviewed, with an emphasis on the modes of action of different active phases. The main part of the review focuses on the role of carbon-metal compound active phase interfaces with an emphasis on the synergistic and additive effects. The procedures of carbon oxidative pretreatment and an overview of metal-free carbon catalysts for OER are presented. Then, the successful synthesis protocols of composite materials are presented with a discussion on the specific catalytic activity of carbon composites with metal hydroxides/oxyhydroxides/oxides, chalcogenides, nitrides and phosphides. Finally, a summary and outlook on carbon-based composites for low temperature water electrolysis are presented.

There is an overwhelming desire to develop new sulfide oxidation electrocatalysts that perform at low potentials and exhibit high current density for the removal and efficient sensing of sulfide. This article describes a comparative electrochemical analysis of various commercially available carbon materials and polymer/surfactant composite electrocatalysts for direct electrooxidation of sulfide in an aqueous solution. The composites were prepared from five different carbon materials multiwalled carbon nanotubes, fullerene-C 60 , graphene, glassy carbon, and carbon nanofibers (CNF) and four different polymers: chitosan, polyvinylidene fluoride, Nafion, and indigenously synthesized poly[2-(methacryloyloxy)ethyl] trimethylammonium chloride (PMTC). The carbon@polymer composites were prepared by a simple ultrasonication technique, and the electrodes were prepared by drop-drying the prepared composite on indium tin oxide (ITO) substrates. The CNF@PMTC showed the highest positive zeta potential that allowed an accumulation of many negatively charged sulfide ions at the CNF@PMTC surface. Cyclic voltammetry was used for the electrooxidation of sulfide in an aqueous solution of tris buffer (0.05 M; pH 8.0) and KNO 3 (0.1 M). The lowest sulfide oxidation peak potential (i. e., -51 mV vs. standard hydrogen electrode) with a high catalytic current response (730 μA/cm 2 ) of the CNF@PMTC-modified ITO electrode among the tested and previously reported carbon-based electrode materials make it ideal for direct sulfide electrooxidation. Taking this and its simple preparation method into account, CNF@PMTC can be considered a benchmark carbon-based electrocatalyst for sulfide oxidation., (© 2021 Wiley-VCH GmbH.)

Because of the abundance of transition metals, their enhanced electrochemical/chemical efficiency on par with the benchmark catalysts, long-term stability, etc., the expansion of transition metal/metal oxide-based electrocatalysts for oxygen evolution, urea oxidation reactions and 4-nitrophenol reduction becomes indispensable. In particular, the abundant availability along with improved electrochemical performance is crucial for fuel cell applications when it comes to large scale commercialization. In this work, we report the synthesis of a trimetallic metal-organic framework based on Ni, Co and Zn using BTC as a linker and the preparation of its metal oxide - carbon composites at different temperatures, 600, 700 and 800 °C (TM-MOF-600, TM-MOF-700, and TM-MOF-800) by carbonization under an inert atmosphere. The PXRD pattern of TM-MOF complemented well with the simulated XRD patterns of Co-Ni-BTC MOF as well as Zn-BTC MOF, whereas the PXRD pattern of the carbonized samples indicated the presence of three types of metal oxides i.e., CoO, NiO, and ZnO. TEM indicated spherical morphology of TM-MOF, upon calcination, an irregular agglomeration occurred and the average particle size was found to be 60-110 nm. The as-prepared TM-MOF and its carbon composites were tested for their electrocatalytic as well as catalytic activities towards oxygen evolution, urea oxidation and 4-nitrophenol reduction reactions. Electrochemical results indicate the better performance of TM-MOF-800 in both OER and UOR reactions with an onset potential of 1.66 V (OER) and 1.37 V (UOR) at a current density of 10 mA cm -2 . The long-term stability of these catalysts under alkaline conditions indicates excellent stability. Besides, the urea electrolyzed products were analyzed by gas chromatography to get clear insights on the formed products. Catalytic reduction of 4-nitrophenol in the presence of excess NaBH 4 showed excellent conversion to 4-amino phenol in short duration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Macroporous carbon materials (MCMs) are used extensively for many electrocatalytic applications, particularly as catalysts for oxygen reduction reactions (ORRs)-for example, in fuel cells. However, complex processes are currently required for synthesis of MCMs. We present a rapid and facile synthetic approach to produce tailored MCMs efficiently via pyrolysis of sulfonated aniline oligomers (SAOs). Thermal decomposition of SAO releases SO 2 gas which acts as a blowing agent to form the macroporous structures. This process was used to synthesise three specifically tailored nitrogen (N)-doped MCM catalysts: N-SAO, N-SAO (phenol formaldehyde) (PF) and N-SAO-reduced graphene oxide (rGO). Analysis using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the formation of macropores (100-350 µm). Investigation of ORR efficacy showed that N-SAOPF performed with the highest onset potential of 0.98 V (vs. RHE) and N-SAOrGO showed the highest limiting current density of 7.89 mAcm -2 . The macroporous structure and ORR efficacy of the MCM catalysts synthesised using this novel process suggest that this method can be used to streamline MCM production while enabling the formation of composite materials that can be tailored for greater efficiency in many applications.

Numerously different porous carbons have been prepared and used in a wide range of practical applications. Porous carbons are also ideal electrode materials for efficient energy storage devices due to their large surface areas, capacious pore spaces, and superior chemical stability compared to other porous materials. Not only the electrical double-layer capacitance (EDLC)-based charge storage but also the pseudocapacitance driven by various dopants in the carbon matrix plays a significant role in enhancing the electrochemical supercapacitive performance of porous carbons. Since the electrochemical capacitive activities are primarily based on EDLC and further enhanced by pseudocapacitance, high-surface carbons are desirable for these applications. The porosity of carbons plays a crucial role in enhancing the performance as well. We have recently witnessed that metal-organic frameworks (MOFs) could be very effective self-sacrificing templates, or precursors, for new high-surface carbons for supercapacitors, or ultracapacitors. Many MOFs can be self-sacrificing precursors for carbonaceous porous materials in a simple yet effective direct carbonization to produce porous carbons. The constituent metal ions can be either completely removed during the carbonization or transformed into valuable redox-active centers for additional faradaic reactions to enhance the electrochemical performance of carbon electrodes. Some heteroatoms of the bridging ligands and solvate molecules can be easily incorporated into carbon matrices to generate heteroatom-doped carbons with pseudocapacitive behavior and good surface wettability. We categorized these MOF-derived porous carbons into three main types: (i) pure and heteroatom-doped carbons, (ii) metallic nanoparticle-containing carbons, and (iii) carbon-based composites with other carbon-based materials or redox-active metal species. Based on these cases summarized in this review, new MOF-derived porous carbons with much enhanced capacitive performance and stability will be envisioned., Competing Interests: The authors declare no conflict of interest.

The synthesis of morphology-controlled carbon-coated nanostructured LiFePO 4 (LFP/Carbon) cathode materials by surfactant-assisted hydrothermal method using block copolymers is reported. The resulting nanocrystalline high surface area materials were coated with carbon and designated as LFP/C123 and LFP/C311. All the materials were systematically characterized by various analytical, spectroscopic and imaging techniques. The reverse structure of the surfactant Pluronic® 31R1 (PPO-PEO-PPO) in comparison to Pluronic® P123 (PEO-PPO-PEO) played a vital role in controlling the particle size and morphology which in turn ameliorate the electrochemical performance in terms of reversible specific capacity (163 mAh g -1 and 140 mAh g -1 at 0.1 C for LFP/C311 and LFP/C123, respectively). In addition, LFP/C311 demonstrated excellent electrochemical performance including lower charge transfer resistance (146.3 Ω) and excellent cycling stability (95 % capacity retention at 1 C after 100 cycles) and high rate capability (163.2 mAh g -1 at 0.1 C; 147.1 mAh g -1 at 1 C). The better performance of the former is attributed to LFP nanoparticles (<50 nm) with a specific spindle-shaped morphology. Further, we have also evaluated the electrode performance with the use of both PVDF and CMC binders employed for the electrode fabrication., Competing Interests: Indian patent application is pending for inventors P. Selvam, S. Khan and R.P. Raj (Provisional Number: 201841047364)., (©2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

A metal-free catalyst is described that consists of a composite that can be prepared from mesoporous carbon spheres (MCS) and graphene oxide (GO) under mild aqueous synthetic conditions. The reduced graphene oxide (rGO) sheets tend to aggregate, but due to the insertion of MCS, the aggregation is prevented. This leads to a larger surface area and more adsorption sites for the cancer drug doxorubicin (DOX). The π-interaction between DOX and rGO is also beneficial for the adsorption of DOX. A glassy carbon electrode (GCE) was modified with the composite and used to detect low levels of DOX, typically at a peak potential near -0.45 V (vs. Ag/AgCl). The modified GCE has a wide linear response range (10 nM - 10 μM), a low limit of detection (1.5 nM; at S/N = 3), excellent selectivity, long-term storage stability and reproducibility. It was applied to the determination of DOX in spiked serum where it gave reliable results. Graphical abstract Schematic representation of the preparation of mesoporous carbon spheres/reduced graphene oxide (MCS/rGO) sample, and the CV scan of doxorubicin (DOX) on MCS/rGO based nanoprode.

This work reports the successful preparation of nanoporous iron oxide/carbon composites through the in-situ growth of Prussian blue (PB) nanoparticles on the surface of graphene oxide (GO) nanosheets. The applied thermal treatment allows the conversion of PB nanoparticles into iron oxide (Fe 2 O 3 ) nanoparticles. The resulting iron oxide/carbon composite exhibits higher specific capacitance at all scan rates than pure GO and Fe 2 O 3 electrodes due to the synergistic contribution of electric double-layer capacitance from GO and pseudocapacitance from Fe 2 O 3 . Notably, even at a high current density of 20 A g -1 , the iron oxide/carbon composite still shows a high capacitance retention of 51%, indicating that the hybrid structure provides a highly accessible path for diffusion of electrolyte ions.

In this work, magnetic Co/C microrods were successfully synthesized using direct carbonization of [Co 3 (BTC) 2 (H 2 O) 12 ] precursors. After the carbonization, the original shape of the precursors was well-maintained, while the magnetic Co nanoparticles were well dispersed in the carbon matrix. The Co/C microrods were used as adsorbents for the adsorption of methyl blue (MB), acid fuchsin (AF), malachite green (MG), rhodamine B (Rh B), methyl orange (MO) and methylene blue (MTB) from their aqueous solutions. The results show that Co/C microrods can selectively adsorb triphenylmethane (TPM) dyes, while the adsorption capacities are about 13960, 11,610 and 4893 mg/g for MB, AF and MG dyes, respectively. The adsorption mechanism can be attributed to π-π interaction forces between the sp 2 graphitic carbon in Co/C microrods and the triphenyl structure of dyes. In addition, the synthesized magnetic Co/C microrods can be easily removed from water using magnetic separation, and subsequently, regenerated using ethanol treatment., (Copyright © 2018. Published by Elsevier Inc.)

Sodium-ion batteries suffer the disadvantages of poor rate performance and cycling stability due to its sluggish sodiation kinetics. A rational design strategy for both materials compositions and structures has been proposed to meet these challenges. Herein, a triple-component composite derived from metal-organic frameworks, comprising FeS 2 , nitrogen-sulfur co-doped porous carbon, and reduced graphene oxide (FeS 2 @NSC/G), has been successfully synthesized. With the capacities contributions from different sodium storage routes (diffusion-controlled processes and surface capacitive processes) at varies rate conditions, it is aiming to make full use of each component in the electrode composite and their unique porous structures. Expected electrode properties have been achieved and related electrochemical behaviors have also been investigated. The strategy would present a promising thought for composites design, which could enhance high-rate electrochemical energy storage performances.

We present a new universal method to accelerate calculations of transmission function and electrical conductance of 2D materials, the supercell of which may contain hundreds or thousands of atoms. The verification of the proposed method is carried out by exemplarily calculating the electrical characteristics of graphene and graphane films. For the first time, we calculated the transmission function and electrical conductance of pillared graphene, composite film of carbon nanotubes (CNTs)/graphene. The electrical conductance of different models of this material was calculated in two mutually perpendicular directions. Regularities in resistance values were found.

Nitrogen-doped single-walled carbon nanohorns (N-SWCNHs) are porous carbon material characterized by unique horn-shape structures with high surface areas and good conductivity. Moreover, they can be mass-produced (tons/year) using a novel proprietary process technology making them an attractive material for various industrial applications. One of the applications is the encapsulation of sulfur, which turns them as promising conductive host materials for lithium-sulfur batteries. Therefore, we explore for the first time the electrochemical performance of industrially produced N-SWCNHs as a sulfur-encapsulating conductive material. Fabrication of lithium-sulfur cells based on N-SWCNHs with sulfur composite could achieve a remarkable initial gravimetric capacity of 1650 mA h g -1 , namely equal to 98.5% of the theoretical capacity (1675 mA h g -1 ), with an exceptional sulfur content as high as 80% in weight. Using cyclic chronopotentiometry and impedance spectroscopy, we also explored the dissolution mechanism of polysulfides inside the electrolyte.

Synergy between graphitic nanocarbon, obtainable from food waste through cracking of biomethane, and iron oxide nanoparticles provides access to efficient bifunctional electro catalysts. Dissolution of potassium-intercalated graphitic nanocarbons yields graphenide solutions with calibrated, small lateral size-reduced graphenes that are used subsequently as reducing agents of iron metal salts. This results in the strong binding of small size (2-5 nm) nanoparticles on the carbon framework homogeneously within the composite material, accessibility of the catalytic centers, and good conductivity provided by the underlying carbon framework. The iron oxide nanocarbon electrocatalyst performances are highlighted by the overall overpotential of approximately 1 V needed to reach the benchmark threshold of 10 mA cm -2 for the oxygen reduction reaction and the particular activity towards oxygen evolution reaction (η≈0.4 V at 10 mA cm -2 ), comparable to that of the precious RuO 2 and IrO 2 catalysts. This iron oxide/nanocarbon electrocatalyst is versatile, remarkably active, stable, and truly sustainable., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This study demonstrates the first example of completely food-based edible electrochemical sensors. The new edible composite electrodes consist of food materials and supplements serving as the edible conductor, corn, and olive oils as edible binders, vegetables as biocatalysts, and food-based packing sleeves. These edible composite electrodes are systematically characterized for their attractive electrochemical properties, such as potential window, capacitance, redox activity using various electrochemical techniques. The sensing performance of the edible carbon composite electrodes compares favorably with that of "traditional" carbon paste electrodes. Well defined voltammetric detection of catechol, uric acid, ascorbic acid, dopamine, and acetaminophen is demonstrated, including sensitive measurements in simulated saliva, gastric fluid, and intestinal fluid. Furthermore, successful biosensing applications are realized by incorporating a mushroom and horseradish vegetable tissues with edible carbon pastes for imparting biocatalytic activity toward the biosensing of phenolic and peroxide compounds. The attractive sensing performance of the new edible sensors indicates considerable promise for physiological monitoring applications and for developing edible and ingestible devices for diverse biomedical applications., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen has been hailed as a clean and sustainable alternative to finite fossil fuels in many energy systems. Water splitting is an important method for hydrogen production in high purity and large quantities. To accelerate the hydrogen evolution reaction (HER) rate, it is highly necessary to develop high efficiency catalysts and to select a proper electrolyte. Herein, the performances of non-noble metal-based carbon composites under various pH values (acid, alkaline and neutral media) for HER in terms of catalyst synthesis, structure and molecular design are systematically discussed. A detailed analysis of the structure-activity-pH correlations in the HER process gives an insight on the origin of the pH-dependence for HER, and provide guidance for future HER mechanism studies on non-noble metal-based carbon composites. Furthermore, this Review gives a fresh impetus to rational design of high-performance noble-metal-free composites catalysts and guide researchers to employ the established electrocatalysts in proper water electrolysis technologies., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Carbon nanofibers, CNFs, due to their superior strength, conductivity, flexibility, and durability have great potential as a material resource but still have limited use due to the cost intensive complexities of their synthesis. Herein, we report the high-yield and scalable electrolytic conversion of atmospheric CO2 dissolved in molten carbonates into CNFs. It is demonstrated that the conversion of CO2 → CCNF + O2 can be driven by efficient solar, as well as conventional, energy at inexpensive steel or nickel electrodes. The structure is tuned by controlling the electrolysis conditions, such as the addition of trace transition metals to act as CNF nucleation sites, the addition of zinc as an initiator and the control of current density. A less expensive source of CNFs will facilitate its adoption as a societal resource, and using carbon dioxide as a reactant to generate a value added product such as CNFs provides impetus to consume this greenhouse gas to mitigate climate change.

One-pot method for metal oxide-carbon composite microsphere with three-dimensional ordered macroporous (3DOM) structure is first introduced. The 3DOM structured SnO2 -carbon microspheres prepared as the first target material show superior electrochemical properties as anode material for lithium ion batteries. The newly developed process can be applied to the preparation of 3DOM-structured metal oxide-carbon composite microspheres for wide applications., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)