Synthesis of porous carbon nanomaterials and their application in tetracycline removal from aqueous solutions

The low-cost and efficient elimination of tetracycline from wastewater and to decrease the concentration in soils,sediments,rivers,underground water,or lakes are crucial to human health.Herein,threedimensional porous carbon nanomaterials were synthesized using glucose and NH_(4)Cl by sugarblowing process at 900℃ and then oxidized under air atmosphere for surface functional group modification.The prepared 3D porous carbon nanomaterials were applied for the removal of tetracycline from aqueous solutions.The sorption isotherms were well simulated by the Langmuir model,with the calculated sorption capacity of 2378 mg·g^(-1) for C-450 at pH=6.5,which was the highest value of today's reported materials.The porous carbon nanomaterials showed high stability at acidic conditions and selectivity in high salt concentrations.The good recycle ability and high removal efficiency of tetracycline from natural groundwater indicated the potential application of the porous carbon nanomaterials in natural environmental antibiotic pollution cleanup.The outstanding sorption properties were attributed to the structures,surface areas and functional groups,strong interactions such as H-bonding,π-π interaction,electrostatic attraction,etc.This paper highlighted the synthesis of porous carbon nanomaterials with high specific surfaces,high sorption capacities,stability,and reusability in organic chemicals'pollution treatment.

Effects of Carbon Nanomaterials on Soil Enzyme Activity of Turfgrass

[Objectives]This study was conducted to evaluate the effects of carbon nanomaterials on soil ecosystem and explore the ecological risks of environmental exposure of carbon nanomaterials. [Methods] The effects of carbon nanomaterials on soil enzyme activity was studied by adding graphene, graphene oxide and carbon nanotubes to turfgrass soil. [Results] Compared with the control(CK), the activity of soil protease, sucrase, alkaline phosphatase and catalase was not significantly affected by carbon nanomaterials. Under the treatment of carbon nanotubes, urease activity was significantly lower than that of graphene and graphene oxide, and dehydrogenase activity was significantly lower than that of the CK, graphene and graphene oxide. [Conclusions] This study provides a theoretical basis for the safe application of carbon nanomaterials.

Carbon nanomaterials and their composites for supercapacitors

As a type of energy storage device between traditional capacitors and batteries,the supercapacitor has the advantages of energy saving and environmental protection,high power density,fast charging and discharging speed,long cycle life,and so forth.One of the key factors affecting the performance of supercapacitor is the electrode material.Carbon materials,such as carbon nanotube,graphene,activated carbon,and carbon nanocage,are most widely concerned in the application of supercapacitors.The synergistic effect of composites can often obtain excellent results,which is one of the common strategies to increase the electrochemical performance of supercapacitors.To further improve the performance of binary composites,it is a relatively simple method to increase the components as the“bridge”between the two materials to form the ternary composites.The review mainly introduces the current research progress of supercapacitors with pure carbon nanomaterials and multistage carbon nanostructures(composites)as electrodes.The characteristics and application directions of different pure carbon nanomaterials are introduced in detail.Different ways of multilevel structure(material)composite have their own effects on the development of high-performance supercapacitors.We also highlight the recent advances related to these fields and provide our insight into high-energy supercapacitors.

Synthesis and Characterization of W-doped TiO_2 Supported by Hybrid Carbon Nanomaterials of Multi-walled Carbon Nanotubes and C_(60) Fullerene by a Hydrothermal Method

W-doped TiO2 supported by hybrid carbon nanomaterials of multi-walled carbon nanotubes and C60 fullerene was synthesized by a simple hydrothermal method. The material displayed high visible light photocatalytic activity. X-ray diffraction, field emission transmission electron microscopy, ultra violet/visible light absorption and photoluminescence spectroscopy were used to characterize the material as photoeatalyst. Photocatalytic activity on the degradation of Rhodamine B dye in an aqueous solution under ultraviolet light and visible light irradiation was also studied. The experimental results indicated that the photocatalytic activity of the material was much higher than that of pure TiO2 or Degussa P25 TiO2.

Versatile Functionalization of Carbon Nanomaterials by Ferrate(Ⅵ)

As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel oxidizing agent for materials chemistry,especially for the oxidation of carbon materials.However,the reported reactivity in liquid phase(H2SO4 medium)is confusing,which ranges from aggressive to moderate,and even incompetent.Meanwhile,the solid-state reactivity underlying the“dry”chemistry of ferrate(VI)remains poorly understood.Herein,we scrutinize the reactivity of K2FeO4 using fullerene C60 and various nanocarbons as substrates.The results unravel a modest reactivity in liquid phase that only oxidizes the active defects on carbon surface and a powerful oxidizing ability in solid state that can open the inert C=C bonds in carbon lattice.We also discuss respective benefit and limitation of the wet and dry approaches.Our work provides a rational understanding on the oxidizing ability of ferrate(VI)and can guide its application in functionalization/transformation of carbons and also other kinds of materials.

Applications of carbon nanomaterials in perovskite solar cells for solar energy conversion

The energy issues and environmental concern have led to intense research activities in renewable energy conversion,such as photovoltaic(PV)to convert solar energy into electricity.Perovskite solar cells(PSCs)based on metal halides are rapidly emerging as the most promising and competing PV technology due to its high record power conversion efficiencies and potentially low production costs.Conductive carbon materials,which are abundantly available and low-cost,are introduced into the PSCs.This article provides a mini review of applications of carbon materials for perovskite solar cells.Firstly,a brief introduction of the development of perovskite solar cell is provided.Secondly,applications of carbon nanomaterials in perovskite solar cells are presented and discussed.Finally,an outlook and perspective on the future research directions of carbon nanomaterial for perovskite solar cells is provided.

Comparative Study on the Effects of Three Carbon Nanomaterials on the Growth of Festuca arundinacea in Compost Substrate

[Objectives] This study was conducted to provide a scientific basis for the utilization of municipal solid waste resources, the remediation of contaminated substrates and the ecological safety of urban lawn planting. [Methods] Graphene, multi-layer graphene oxide and multi-walled carbon nanotubes were added to municipal solid waste(MSW) compost as turf substrate to determine the morphological indicators such as turfgrass biomass, chlorophyll contents and plant height. [Results] There were no significant differences in the plant height of Festuca arundinacea between different treatment groups in the first 30 d. The effects of adding different carbon nanomaterials on the fresh and dry weights of F. arundinacea were not significantly different. The aboveground biomass of F. arundinacea was the largest after adding graphene oxide, and the underground fresh weight decreased significantly in the hydroxyl multi-walled carbon nanotube treatment compared with the control. As to the chlorophyll content, the graphene oxide treatment was the highest, but there were no significant differences between all the treatment groups and the control group. [Conclusions] This study can provide data support for MSW compost substrate, lawn planting system and heavy metal pollutant passivating agents.

Copper-cerium oxides supported on carbon nanomaterial for preferential oxidation of carbon monoxide

The CuxO-CeO2/Fe@CNSs, CuxO-CeO2/MWCNTs-Co and CuxO-CeO2/MWCNTs-Ni catalysts were prepared by the impregnation method and characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, H2-temperature programmed reduction and N2 adsorption-desorption techniques. It was found that the Fe nanoparticles were encapsulated into the multi-layered carbon nanospheres （CNSs）. However, the multi-wall carbon nanotubes （MWCNTS） were generated on the Co/Al2O3 and Ni/Al2O3 precursor. The addition of carbon nanomaterial as supports could improve structural properties and low-temperature activity of the CuO-CeO2 catalyst, and save the used amount of metal catalysts in the temperature range with high selectivity for CO oxidation. The copper-cerium oxides supported on carbon nanomaterial had good resistence to H2O and CO2.

M0S_(2) nanoparticles grown on carbon nanomaterials for lubricating oil additives

In this study,the nanocomposites of MoS_(2) nanoparticles(NPs)grown on carbon nanotubes(MoS_(2)@CNT),graphene(MoS_(2)@Gr),and fullerene C60(MoS_(2)@C60)were synthesized,characterized,and evaluated for potential use as lubricant additives.By using the benefit of the synergistic effect between MoS_(2) and carbon nanomaterials(CNMs),these nanocomposites can be well dispersed in polyalkylene glycol(PAG)base oil and show superior stability compared with pure MoS_(2) NPs.Moreover,the dispersions of MoS_(2)@CNT,MoS_(2)@Gr,and MoS_(2)@C60 added in PAG have noticeably improved friction reducing and antiwear(AW)behaviors at elevated temperature for comparison with that of PAG and PAG containing CNT,Gr,C60,and M0S2 NPs,respectively.The enhanced lubricating properties of these nanocomposites were also elucidated by exploring the tribofilm formed on the disc.

Carbon nanomaterials for cardiovascular theranostics:Promises and challenges

Cardiovascular diseases(CVDs)are the leading cause of death worldwide.Heart attack and stroke cause irreversible tissue damage.The currently available treatment options are limited to“damage-control”rather than tissue repair.The recent advances in nanomaterials have offered novel approaches to restore tissue function after injury.In particular,carbon nanomaterials(CNMs)have shown significant promise to bridge the gap in clinical translation of biomaterial based therapies.This family of carbon allotropes(including graphenes,carbon nanotubes and fullerenes)have unique physiochemical properties,including exceptional mechanical strength,electrical conductivity,chemical behaviour,thermal stability and optical properties.These intrinsic properties make CNMs ideal materials for use in cardiovascular theranostics.This review is focused on recent efforts in the diagnosis and treatment of heart diseases using graphenes and carbon nanotubes.The first section introduces currently available derivatives of graphenes and carbon nanotubes and discusses some of the key characteristics of these materials.The second section covers their application in drug delivery,biosensors,tissue engineering and immunomodulation with a focus on cardiovascular applications.The final section discusses current shortcomings and limitations of CNMs in cardiovascular applications and reviews ongoing efforts to address these concerns and to bring CNMs from bench to bedside.

The use of carbon nanomaterials in membrane distillation membranes:a review

Membrane distillation(MD)is a thermal-based separation technique with the potential to treat a wide range of water types for various applications and industries.Certain challenges remain however,which prevent it from becoming commercially widespread including moderate permeate flux,decline in separation performance over time due to pore wetting and high thermal energy requirements.Nevertheless,its attractive characteristics such as high rejection(ca.100%)of nonvolatile species,its ability to treat highly saline solutions under low operating pressures(typically atmospheric)as well as its ability to operate at low temperatures,enabling waste-heat integration,continue to drive research interests globally.Of particular interest is the class of carbon-based nanomaterials which includes graphene and carbon nanotubes,whose wide range of properties have been exploited in an attempt to overcome the technical challenges that MD faces.These low dimensional materials exhibit properties such as high specific surface area,high strength,tuneable hydrophobicity,enhanced vapour transport,high thermal and electrical conductivity and others.Their use in MD has resulted in improved membrane performance characteristics like increased permeability and reduced fouling propensity.They have also enabled novel membrane capabilities such as in-situ fouling detection and localised heat generation.In this review we provide a brief introduction to MD and describe key membrane characteristics and fabrication methods.We then give an account of the various uses of carbon nanomaterials for MD applications,focussing on polymeric membrane systems.Future research directions based on the findings are also suggested.

Photo-responsive shape memory polymer composites enabled by doping with biomass-derived carbon nanomaterials

As photothermal conversion agents,carbon nanomaterials are widely applied in polymers for light-triggered shape memory behaviors on account of their excellent light absorption.However,they are usually derived from non-renewable fossil resources,which go against the demand for sustainable development.Biomass-derived carbon nanomaterials are expected as alternatives if they are designed with good dispersibility as well as splendid photothermal properties.Up to date,very few researches focused on this area.Herein,we report a novel light-triggered shape memory composite by incorporating renewable biomass-derived carbon nanomaterials into acrylate polymers without deep purification and processing.These functionalized carbon nanomaterials not only have stable dispersion in polymers as fillers,but also can endow the polymers with excellent and stable thermal and photothermal responsive properties in biological friendly environment.With the introduction of biomass-derived carbon nanomaterials,the mechanical properties of the composites are also further enhanced with the formation of hydrogen bonding between the carbon nanomaterials and the polymers.Notably,the doping of 1%carbon nanomaterials endows the polymer with sufficient hydrogen bonds that not only exhibit excellent thermal and photothermal responsive properties,but also with enough space for the motion of chains.These properties make such composite a promising and safe candidate for shape memory applications,which provide a new avenue in smart fabrics or intelligent soft robotics.

Mesoporous carbon nanomaterials induced pulmonary surfactant inhibition,cytotoxicity,inflammation and lung fibrosis

Environmental exposure and health risk upon engineered nanomaterials are increasingly concerned. The family of mesoporous carbon nanomaterials（MCNs） is a rising star in nanotechnology for multidisciplinary research with versatile applications in electronics,energy and gas storage, and biomedicine. Meanwhile, there is mounting concern on their environmental health risks due to the growing production and usage of MCNs. The lung is the primary site for particle invasion under environmental exposure to nanomaterials. Here, we studied the comprehensive toxicological profile of MCNs in the lung under the scenario of moderate environmental exposure. It was found that at a low concentration of 10 μg/mL MCNs induced biophysical inhibition of natural pulmonary surfactant. Moreover, MCNs at similar concentrations reduced viability of J774 A.1 macrophages and lung epithelial A549 cells.Incubating with nature pulmonary surfactant effectively reduced the cytotoxicity of MCNs.Regarding the pro-inflammatory responses, MCNs activated macrophages in vitro, and stimulated lung inflammation in mice after inhalation exposure, associated with lung fibrosis.Moreover, we found that the size of MCNs played a significant role in regulating cytotoxicity and pro-inflammatory potential of this nanomaterial. In general, larger MCNs induced more pronounced cytotoxic and pro-inflammatory effects than their smaller counterparts. Our results provided valuable information on the toxicological profile and environmental health risks of MCNs, and suggested that fine-tuning the size of MCNs could be a practical precautionary design strategy to increase safety and biocompatibility of this nanomaterial.

Low-temperature synthesis of sp^2 carbon nanomaterials

sp^2 carbon nanomaterials are mainly composed of sp^2-hybridized carbon atoms in the form of a hexagonal network. Due to the p bonds formed by unpaired electrons, sp^2 carbon nanomaterials possess excellent electronic, mechanical, and optical properties, which have attracted great attention in recent years.As the advanced sp^2 carbon nanomaterials, graphene and carbon nanotubes(CNTs) have great potential in electronics, sensors, energy storage and conversion devices, etc. The low-temperature synthesis of graphene and CNTs are indispensable to promote the practical industrial application. Furthermore, graphene and CNTs can even be expected to directly grow on the flexible plastic that cannot bear high temperature,expanding bright prospects for applications in emerging flexible nanotechnology. An in-depth understanding of the formation mechanism of sp^2 carbon nanomaterials is beneficial for reducing the growth temperature and satisfying the demands of industrial production in an economical and low-cost way. In this review, we discuss the main strategies and the related mechanisms in low-temperature synthesis of graphene and CNTs, including the selection of precursors with high reactivity, the design of catalyst, and the introduction of additional energy for the pre-decomposition of precursors. Furthermore, challenges and outlooks are highlighted for further progress in the practical industrial application.

Percolation of carbon nanomaterials for high-k polymer nanocomposites

High-k polymer composite materials are next-generation dielectrics that show amazing applications in diverse electrical and electronic devices. Establishing near-percolated network of conducting filler in an insulating polymer matrix is a promising approach to develop flexible high-k dielectrics. However, challenges still exist today on fine controlling the network morphology to achieve extremely high k values and low losses simultaneously. The relationship between the network morphology and the dielectric properties of polymer composites is raising a number of fundamental questions. Herein, recent progress towards high-k polymer composites based on carbon nanomaterials is reviewed. Particular attention is paid on the influence of the network morphology on the dielectric properties. Some perspectives that warrant further investigation in the future are also addressed.

Bimetallic AgNi nanoparticles anchored onto MOF-derived nitrogen-doped carbon nanostrips for efficient hydrogen evolution

Hydrogen energy has long been recognized as a clean alternative to conventional fossil fuels,which can be applied in a wide range of transportation and power generation applications.The rational design and engineering of high-performance and robust catalysts for hydrogen evolution reaction(HER)shows not a great significance but a challenge for efficient electrochemical water splitting.Herein,a new type of Nibased Ni-ABDC precursor has been obtained,which leads to the formation of N-doped porous carbon nanomaterials uniformly coated with wellproportioned bimetallic AgNi alloys via a stepwise strategy.To their credit,all samples of AgNi/NC-X are structurally calcined from the pristine AgNi-ABDC-X by tuning the different concentration of AgNO3,which means all of them maintain the vermicelli-like morphology compared with Ni-ABDC.The series of AgNi/NC-X materials can be regarded as effective electrocatalysts for HER both in acidic and alkaline media,but an acid-leaching phenomenon is observed.Among them,the as-prepared AgNi/NC-2 exhibits a low overpotential of 103 mV at the current density of 10 mA cm^(-2)and decent durability with a high retention rate of 90.9%after 10 h in 1.0 mol L^(-1)KOH electrolyte.The compelling HER properties of AgNi/NC-2 can be attributed to the synergistic effect between the hierarchical carbon materials,partial N-doping and abundant AgNi alloys.Meanwhile,this study provides a practicable method for the development of efficient HER electrocatalysts for energy applications,which can be conveniently prepared through the reasonable introduction of active components in the crystalline inorganic-organic precursors.©2021 Institute of Process Engineering,Chinese Academy of Sciences.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.,Ltd.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Recent advances in nanomaterials for high-performance Li–S batteries

This article reviews nanotechnology as a practical solution for improving lithium-sulfur batteries. Lithiumsulfur batteries have been widely examined because sulfur has many advantageous properties such as a high crustal abundance, low environmental impact, low cost, high gravimetric(2600 W h kg-1) and volumetric(2800 W h L-1) energy densities, assuming complete conversion of sulfur to lithium sulfide(Li2S)upon lithiation. However, lithium-sulfur batteries have not yet reach commercialization due to demerits involving the formation of soluble lithium polysulfides(Li2Sn, n=3–8), low electrical conductivity, and low loading density of sulfur. These issues arise mainly due to the polysulfide shuttle phenomenon and the inherent insulating nature of sulfur. To overcome these issues, strategies have been pursued using nanotechnology applied to porous carbon nanocomposites, hollow one-dimensional carbon nanomaterials, graphene nanocomposites, and three-dimensional carbon nanostructured matrices. This paper aims to review various solutions pertaining to the role of nanotechnology in synthesizing nanoscale and nanostructured materials for advanced and high-performance lithium–sulfur batteries. Furthermore, we highlight perspective research directions for commercialization of lithium–sulfur batteries as a major power source for electric vehicles and large-scale electric energy storage.

Fullerene-derived boron-doped defective nanocarbon for highly selective H_(2)O_(2) electrosynthesis

Electrochemical production of hydrogen peroxide(H_(2)O_(2))via the two-electron(2e-)pathway of oxygen reduction reaction(ORR)supplies an auspicious alternative to the current industrial anthraquinone process.Nonetheless,it still lacks efficient electrocatalysts to achieve high ORR activity together with 2e-selectivity simultaneously.Herein,a boron-doped defective nanocarbon(B-DC)electrocatalyst is synthesized by using fullerene frameworks as the precursor and boric oxide as the boron source.The obtained B-DC materials have a hierarchical porous structure,befitting boron dopants,and abundant topological pentagon defects,exhibiting a high ORR onset potential of 0.78 V and a dominated 2e-selectivity(over 95%).Remarkably,when B-DC electrocatalyst is employed in a real device,it achieves a high H_(2)O_(2) yield rate(247 mg·L^(-1)·h^(-1)),quantitative Faraday efficiency(~100%),and ultrafast organic pollutant degradation rate.The theoretical calculation reveals that the synergistic effect of topological pentagon defects and the incorporation of boron dopants promote the activation of the O_(2) molecule and facilitates the desorption of oxygen intermediate.This finding will be very helpful for the comprehension of the synergistic effect of topological defects and heteroatom dopants for boosting the electrocatalytic performance of nanocarbon toward H_(2)O_(2) production.

Recent Progress of Electrode Materials for Flexible Perovskite Solar Cells

Flexible perovskite solar cells(FPSCs) have attracted enormous interest in wearable and portable electronics due to their high power-per-weight and low cost. Flexible and efficient perovskite solar cells require the development of flexible electrodes compatible with the optoelectronic properties of perovskite. In this review, the recent progress of flexible electrodes used in FPSCs is comprehensively reviewed. The major features of flexible transparent electrodes, including transparent conductive oxides, conductive polymer, carbon nanomaterials and nanostructured metallic materials are systematically compared. And the corresponding modification strategies and device performance are summarized. Moreover, flexible opaque electrodes including metal films, opaque carbon materials and metal foils are critically assessed. Finally, the development directions and difficulties of flexible electrodes are given.

Recent advances in antimony removal using carbon-based nanomaterials:A review

Recently,special attention has been deserved to environmental risks of antimony(Sb)element that is of highly physiologic toxicity to human.Conventional coagulation and ion exchange methods for Sb removal are faced with challenges of low efficiency,high cost and secondary pollution.Adsorption based on carbon nanomaterials(CNMs;e.g.,carbon nanotubes,graphene,graphene oxide,reduced graphene oxide and their derivatives)may provide effective alternative because the CNMs have high surface area,rich surface chemistry and high stability.In particular,good conductivity makes it possible to create linkage between adsorption and electrochemistry,thereby the synergistic interaction will be expected for enhanced Sb removal.This review article summarizes the state of art on Sb removal using CNMs with the form of nano-adsorbents and/or filtration membranes.In details,procedures of synthesis and functionalization of different forms of CNMs were reviewed.Next,adsorption behavior and the underlying mechanisms toward Sb removal using various CNMs were presented as resulting from a retrospective analysis of literatures.Last,we prospect the needs for mass production and regeneration of CNMs adsorbents using more affordable precursors and objective assessment of environmental impacts in future studies.