Surface-modified Carbon Research Articles

Boosting triboelectric performance of PDMS-based nanogenerators through dual-filler embedded triboelectric layers

Triboelectric nanogenerators (TENGs) provide an effective method for harvesting mechanical energy and converting it into electrical power. Polydimethylsiloxane (PDMS)-based TENGs are particularly advantageous due to their excellent mechanical properties, high flexibility, simple manufacturing process, and low cost. In this study, we suggest a PDMS-based TENG by integrating surface-modified carbon nanotubes (SMCs) prepared by pulsed laser ablation (PLA), along with high-permittivity BaTiO3 (BTO) nanoparticles. The combination of SMCs' superior electrical conductivity and BTO's high dielectric constant has synergistically enhanced the TENG's performance. Compared to pristine PDMS-based TENGs, the TENG incorporating 0.05 wt% SMCs and 7 wt% BTO demonstrated a remarkable 200 % increase in voltage (432.44 V) and a 324 % increase in current (39.23 μA). Also, plasma treatment further boosts the triboelectric performance, achieving a voltage of 468 V, a current of 43.04 μA, and a power density of 7.83 W/m².

Engineered hybrid carbon nanohorns-lipid platforms for the delivery of cisplatin to the colorectal cancer

Carbon nanostructures are considered distinctive multi-functional drug delivery platforms for cancer therapy. However, their potential biocompatibility is still a significant challenge and rational design of these carriers is a prospect in the context of efficient cancer therapy. Herein, we report on the synthesis of two bio-inspired carbon nanohorns (CNH) platforms with tumor targeting capabilities for the delivery of cisplatin. Oxidized CNH wrapped with either polyethylene glycol (PEG) and fusogenic lipids (PEG/DSPG CNH-CP) or glutamic acid-cisplatin complex (CNH-GA-CP), revealed nanosized dahlia-like structure approved by dynamic light scattering (DLS) and transmission electron microscopy (TEM) analysis. Further structure features analysis by using RAMAN, FTIR spectroscopy and TGA indicated CNH surface modification. Excitingly, the superior nanofeatures of the CNH platforms was due to the reduced hydrophobic interactions, and thus closely linked to the surface modifications. Both platforms preserved cisplatin toxicity in vitro on C26 cells. The PEGylated nanoplatform demonstrated elongated circulation time compared to the free drug, and showed a site-specific delivery to the tumor site, while reducing the accumulation within kidney. Following 3 i.v. doses at 3 mg/kg of cisplatin, PEGylated CNH significantly delayed tumor growth and improved the life span of C26-bearing BALB/c mice. These notable results were further approved by the histopathological data, demonstrating reduced degeneration, necrosis and inflammation in both kidney and liver tissues following PEGylated nanoplatform administration. In conclusion, our findings suggest that the systemic toxicity of cisplatin including nephrotoxicity can be resolved by delivering this chemotherapeutic through a rationally-fabricated surface-modified carbon nanoplatform to improve the cancer therapy outcome.

Molecular Dynamics Analysis of Surface-Modified Carbon Nanoparticle Reinforced Epoxy Resin.

Surface-modified carbon nanoparticles (CNPs) as reinforcement materials have attracted significant attention due to their potential for substantially enhancing mechanical properties. However, the development and application of CNP-enhanced polymeric materials are constrained by an incomplete understanding of their reinforcement mechanisms, impeding sustainable progress. In this study, we employed molecular dynamics simulations to investigate the mechanical properties of surface-modified CNP-reinforced epoxy resin composites at the microscopic scale. The simulations focused on the tensile process and the nanopinning effect of CNPs within the epoxy resin matrix. Our results indicate that surface-modified CNPs form stronger interfacial connections with the epoxy resin, leading to enhanced mechanical strength of the composites. Quantitative analysis revealed that these composites exhibit higher tensile strength compared to nonmodified counterparts, with a significant improvement in stability due to the robust noncovalent interactions between CNPs and the epoxy matrix. This study elucidates the reinforcement mechanisms of surface-modified CNPs in polymers, providing valuable insights for further optimization and sustainable development of CNP-reinforced polymeric materials.

Enhanced photocatalytic degradation of toluene on surface C- and CN-modified TiO2 microspheres

Surface modified TiO2 materials are widely used in photocatalytic environmental purification processes. The employment of solution might exert a discernible influence on the catalyst. In this study, we incorporated tetrahydrofuran (THF) and pyrrolidine (PY) during the hydrolysis of titanium butoxide (TBOT) to modify the surface of TiO2, successfully synthesizing surface C-modified TiO2 (THF-TiO2) and surface CN-modified TiO2 (PY-TiO2) catalysts. The assistance of THF and PY not only reduced agglomeration, but also increased the specific surface area of both catalysts, leading to the exposure of more active sites in TiO2 during the photocatalytic degradation of toluene. When compared to the unsatisfactory degradation of toluene (80%) and CO2 mineralization efficiencies (40–45 %) observed using unmodified TiO2, the synthesized THF-50-TiO2 and PY-1-TiO2 microspheres demonstrated enhanced toluene degradation efficiency to 100 % and 99.8 %, respectively, and improved mineralization efficiencies to 76 % and 80 % after 120 min of ultraviolet irradiation. The experimental data and characterization results indicate that the surface-modified carbon species in THF-50-TiO2 facilitate the acceleration of electron-hole pair separation and suppress recombination. In contrast, partial nitrogen species introduced into the surface lattice of PY-1-TiO2 narrow its band gap and induce a visible light response. Overall, this study provides two methods to modify the surface of TiO2, which can be applied to prepare outstanding photocatalysts for possible application in the degradation of volatile organic compounds (VOCs) present in the air. Furthermore, it has been confirmed that solution have a significant impact on the catalyst.

Phase-Transition-Promoted Thermoelectric Textiles Based on Twin Surface-Modified CNT Fibers.

With the fast development of new science and technology, wearable devices are in great demand in modern human daily life. However, the energy problem is a long-lasting issue to achieve real smart, wearable, and portable devices. Flexible thermoelectric generators (TEGs) based on thermoelectric conversion systems can convert body waste heat into electricity with excellent flexibility and wearability, which shows a new direction to solving this issue. Here in this work, polyethylenimine (PEI) and gold nanoparticles (Au NPs) twin surface-modified carbon nanotube fibers (CNTFs) were designed and prepared to fabricate thermoelectric textiles (TET) with high performance, good air stability, and high-efficiency power generation. To better utilize the heat emitted by the human body, microencapsulated phase change materials (MPCM) were coated on the hot end of the TET to achieve the phase-transition-promoted TET. MPCM-coated TET device could generate 25.7% more energy than the untreated control device, which indicates the great potential of the phase-transition-promoted TET.

Effect of Refluxing Time and Kinetics of Synthetic Organic Chemicals Removal in Aqueous Solutions by Carbons Produced from Nipa Palm Fronds

The refluxing time is a significant consideration in synthetic study, because it could reflect the kinetics of the reaction process. Synthetic Organic Chemicals (SOCs) are man-made carbon-based compounds that are not likely to evaporate into the atmosphere and hence they could get into aquatic water bodies through terrestrial runoff or discharge from factories. Therefore, this paper investigated the effect of refluxing time and kinetics of Synthetic Organic Chemicals (SOCs) removal in aqueous solutions by carbonized and surface-modified carbons made from Nipa Palm (<i>Nypa Fruticans </i>Wurmb) fronds using chemical oxygen demand (COD) as the measurement parameter. The data showed a rapid reduction of the COD of the SOCs contaminated solutions from 30.19 to 93.46% for PCC, 27.44 to 65.58% for AAC, 41.84 to 98.22% for BAC and 56.71 to 95.16% for CAC between 10 to 60 mins. Optimum reduction was achieved within 20 min of heating the solutions at 150°C. The rapid COD reduction observed for n-propanol indicates that COD is a rapid, inexpensive means of determining organics in water. Kinetic assessment of the results showed that, pseudo-first order kinetic equation did not provide a very good description of COD reduction of the SOCs in aqueous solution by the Nipa palm derived carbons. However, Nipa palm had been adjudged as a beneficial, eco-friendly and locally available source for the development of activated carbon for elimination of organic pollutants in domestic and industrial wastewaters.

Fixed-Bed Column Adsorption Studies of Synthetic Organic Chemicals Using Carbonized and Surface-Modified Carbons from Nipa Palm Leaves

Fixed-Bed Column Adsorption Studies of Synthetic Organic Chemicals Using Carbonized and Surface-Modified Carbons from Nipa Palm Leaves

The effect of modified carbon black and nano-silica, individually and in combination, on the curing, mechanical, and dynamical properties of butyl rubber (IIR)

This study evaluates the effectiveness of a developed surface-modified carbon black, both alone and combined with nano-silica, as a hybrid filler for butyl rubber (IIR) compounds. The modification process, followed by coupling agent treatment, influenced crucial curing properties, including torque, cross-link density, viscosity, stiffness, and curing time. Scanning electron microscopy (SEM) analysis revealed improved filler dispersion and enhanced filler-rubber compatibility due to surface modification. The ∆Torque for compounds containing modified carbon black surpassed others by 13%. Mechanical properties such as tensile strength, elongation at break, modulus, tearing strength, and hardness were significantly influenced by filler type and surface modification. The harness (Shore A) increased to the value of 45 after surface amendment. Dynamic mechanical analysis (DMA) provided insights into storage modulus, loss modulus, and tan δ, showing the impact of filler type and surface modification. The utilization of coupling agent-modified carbon black decreased [Formula: see text] from −24°C to −30°C. Thermal gravimetric analysis (TGA) indicated consistent thermal stability across compounds, while solvent resistance improved with surface modification, as evidenced by swelling ratios. The thermodynamic analysis underscored the importance of filler type and surface modification on compound elasticity and flexibility. Overall, precise selection and optimization of filler materials and surface modifications are crucial for tailoring rubber compound properties to meet specific performance requirements across applications, impacting various aspects including curing, mechanical, dynamic, thermal, solvent resistance, and thermodynamic parameters.

Unraveling the mechanism of enhanced oxygen evolution reaction using NiOx@Fe3O4 decorated on surface-modified carbon nanotubes

Laser-driven synthesis of NiOx@Fe3O4 on surface-modified carbon nanotubes is developed for enhanced oxygen evolution reaction.

Fiber, monolithic fiber and twisted fiber structures: efficient microwave absorption via surface-modified carbon nanotube buckypaper/silicon carbide-based self-sealing layered composites

A variety of self-sealing layered fiber substrates are constructed, and the substrates are converted into absorbers by cladding modification. Microwaves are scattered in all directions at multiple angles in the self-sealing layered fiber structures.

Surface-Modified Carbon Nanotubes with Ultrathin Co3O4 Layer for Enhanced Oxygen Evolution Reaction.

Alkaline water electrolysis is a vital technology for sustainable and efficient hydrogen production. However, the oxygen evolution reaction (OER) at the anode suffers from sluggish kinetics, requiring overpotential. Precious metal-based electrocatalysts are commonly used but face limitations in cost and availability. Carbon nanostructures, such as carbon nanotubes (CNTs), offer promising alternatives due to their abundant active sites and efficient charge-transfer properties. Surface modification of CNTs through techniques such as pulsed laser ablation in liquid media (PLAL) can enhance their catalytic performance. In this study, we investigate the role of surface-modified carbon (SMC) as a support to increase the active sites of transition metal-based electrocatalysts and its impact on electrocatalytic performance for the OER. We focus on Co3O4@SMC heterostructures, where an ultrathin layer of Co3O4 is deposited onto SMCs using a combination of PLAL and atomic layer deposition. A comparative analysis with aggregated Co3O4 and Co3O4@pristine CNTs reveals the superior OER performance of Co3O4@SMC. The optimized Co3O4@SMC exhibits a 25.6% reduction in overpotential, a lower Tafel slope, and a significantly higher turnover frequency (TOF) in alkaline water splitting. The experimental results, combined with density functional theory (DFT) calculations, indicate that these improvements can be attributed to the high electrocatalytic activity of Co3O4 as active sites achieved through the homogeneous distribution on SMCs. The experimental methodology, morphology, composition, and their correlation with activity and stability of Co3O4@SMC for the OER in alkaline media are discussed in detail. This study contributes to the understanding of SMC-based heterostructures and their potential for enhancing electrocatalytic performance in alkaline water electrolysis.

Design strategy of cathodic electrocatalysts to effectively suppress inorganic fouling for long-term stability of reverse electrodialysis

In seawater based-electrochemical devices including reverse electrodialysis (RED) and electrolysis devices, inorganic fouling occurs from the cathodic reaction owing to the precipitation of hydroxides and/or carbonates. Inorganic fouling decreases electrocatalytic activity and disrupts the charge transport, thus reducing power density. In this study, we investigated inorganic fouling over various cathodic electrocatalysts prepared for large-scale RED. Notably, nano-Pt/C which has four times higher scaling control than bulk Pt, exhibited a formation of thin and porous foam-like Mg(OH)2, whereas bulk Pt was coated by a thick and dense film-like precipitate. Surface-modified carbon nanostructures showed a stronger anti-fouling behavior than Pt catalysts at high voltages (≥300-cell-paired RED stacks). In particular, acid–air plasma-treated O-rich functionalized C catalysts produced one-dimensional nanostructures, exhibited excellent electrocatalytic activity and allowed rapid charge transport, resulting in a stable RED performance at a power density of 545 ± 1 W m−2 (current density of 35.17 ± 0.02 A/m−2 over 12-h of operation. This study will promote the upscaling of RED systems toward industrial applications that use natural seawater.

Cobalt Ferrite Surface-Modified Carbon Nanotube Fibers as an Efficient and Flexible Electrode for Overall Electrochemical Water Splitting Reactions.

One of the most practical and environmentally friendly ways to deal with the energy crises and global warming is to produce hydrogen as clean fuel by splitting water. The central obstacle for electrochemical water splitting is the use of expensive metal-based catalysts. For electrocatalytic hydrogen production, it is essential to fabricate an efficient catalyst for the counterpart oxygen evolution reaction (OER), which is a four-electron-transfer sluggish process. Here in this study, we have successfully fabricated cobalt-based ferrite nanoparticles over the surface of carbon nanotube fiber (CNTF) that was utilized as flexible anode materials for the OER and overall electrochemical water splitting reactions. Scanning electron microscopy images with elemental mapping showed the growth of nanoparticles over CNTF, while electrochemical characterization exhibited excellent electrocatalytic performance. Linear sweep voltammetry revealed the reduced overpotential value (260 mV@η10mAcm-2) with a small Tafel slope of 149 mV dec-1. Boosted electrochemical double layer capacitance (0.87 mF cm-2) for the modified electrode also reflects the higher surface area as compared to pristine CNTF (Cdl = 0.022 mF cm-2). Charge transfer resistance for the surface-modified CNTF showed the lower diameter in the Nyquist plot and was consequently associated with the better Faradaic process at the electrode/electrolyte interface. Overall, the as-fabricated electrode could be a promising alternative for the efficient electrochemical water splitting reaction as compared to expensive metal-based electrocatalysts.

Investigation of the effect of adding carbon nanotubes, lower and higher level alcohol additives, in Yellow oleander methyl ester-diesel blend on diesel engine performance

ABSTRACT The current study is to determine the overall performance of a compression ignition engine (CI) employing a B30 (30% Yellow Oleander Methyl Ester (YOME) and 70% diesel) sample including nano and alcohol additives. Initially, the surface-modified carbon nanotubes (CNTs) (at a dosage of 60 mg/L) are sonicated in the B30 blend for 30 mins at 40 kHz and termed B30CNTs60. It was found to be quite stable as evidenced by characterization. The B30CNTs60 blend is then blended with a fixed volume (10%) of n-Butanol, iso-Butanol, and Dimethyl Carbonate (DMC), and referred to as B30CNTs60+n-Butanol10%, B30CNTs60+iso-Butanol10%, and B30CNTs60+DMC 10%. The physicochemical properties of all fuel samples met ASTM criteria and samples were experimented on a 1-cylinder, 4-stroke diesel engine under varying loads. The results revealed that the B30CNTs60+DMC 10% blend enhanced heat release rate (HRR), cylinder pressure (CP), and brake thermal efficiency (BTE) by 11.2%, 8.64%, and 11.92%, respectively. Furthermore, with B30CNTs60+DMC 10% blend, the combustion duration, brake specific fuel consumption (BSFC), carbon monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), nitrogen oxide (NOx), and smoke opacity were reduced by 10.9%, 15.62%, 18.24%, 18.78%, 8.12%, 6.75%, and 10.92% respectively. Finally, the B30CNTs60+DMC 10% blend was suggested to use in CI engines.

Dual-supported nanoscale zero-valent iron for As(III) contaminated groundwater remediation

Nanoscale zero-valent irons (nZVIs) are easy to agglomerate and deactivate, which limited the practical applications in the subsurface for in situ remediation of contaminated groundwater due to poor radius of influence. Here, we utilized the dual support effect of coupling surface-modified carbon black with a surfactant (carboxymethyl cellulose (CMC) or sodium dodecyl sulfate (SDS)) to manipulate the charge, electron, and geometric structure of the interface, the obtained Fe/CB/CMC (wt%=1:1:2) and Fe/CB/SDS (wt%=1:2:1) suspensions exhibited superior removal capacity toward As(III) with capacities of 80.7 and 90.7 mg g-1, respectively. In a clay medium, 25.2% and 18.0% of nZVIs in Fe/CB/CMC-1:1:2 and Fe/CB/SDS-1:2:1 can break through the column while approximately 100% are retained in bare nZVIs under the same conditions. In addition, input velocity and ionic strength demonstrate a positive correlation with the retention of nZVIs in the Fe/CB/CMC-112 and a slight impact on the deposition of nZVIs in the Fe/CB/SDS-121 due to the rheology and charge differences between CMC and SDS. This study demonstrates the feasibility of combining anionic surfactants and carbon supports to enhance the reactivity and mobility of nZVIs for in situ remediation.

Insights into electrogenerated intermediates and rapid screening of electrochemical reactions by surface-modified carbon fiber paper redox spray ionization mass spectrometry

The combination of electrochemistry and mass spectrometry is a powerful analytical tool for studying redox reaction mechanisms and identifying products or intermediates. However, the previously reported devices all require bespoke fabrication and are too complicated to be assembled and used by others. Crucially, the long ion transport distance and small spray volumes make it difficult to capture the short-lived intermediates. We present a practical mass spectrometric method in which surface-modified carbon fiber paper is innovatively applied to detect electrogenerated intermediates. Treating carbon fiber paper with dilute nitric acid removes its surface impurities, enhancing the capability of electro-redox. Electrospray ionization and redox reaction occur simultaneously on the tip of the paper. Transient electro-redox species generate and transfer into gas phase as soon as the appearance of spray. Rapid transport of quantities of electrogenerated ions to the mass spectrometer inlet makes it possible for mass spectrometric identification on the millisecond scale. The short-lived radical cations and iminium ions were successfully captured, reflecting the starting step of the cross-dehydrogenation coupling reaction. The real-time oxidation and online functionalization reactions of tertiary amines were achieved using this device without additional oxidants and electrolytes. In this way we could achieve in-depth mechanistic understanding and rapid screening of serial reactions.

Reutilization of carbon of waste filter cartridge after its surface modification for the fluoride removal from water by continuous flow process.

In the present study, the waste carbon cartridge of the water filter was modified and reutilized for defluoridation of water. The modified carbon was characterized by particle size analysis (PSA), Fourier transformed infrared spectroscopy (FTIR), zeta potential, pHzpc, energy-dispersive X-ray (EDS), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray crystallography (XRD). The adsorptive nature of modified carbon was investigated with pH (4-10), dose (1-5 g/L), contact time (0-180 min), temperature (25-55 °C), fluoride concentration (5-20 mg/L), and the effect of the competitive ions. Adsorption isotherm, kinetics, thermodynamics, and breakthrough studies were evaluated for fluoride uptake on surface-modified carbon (SM*C). Fluoride adsorption on the carbon accepted Langmuir model (R2 = 0.983) and pseudo-second-order kinetic (R2 = 0.956). The presence of HCO3- in the solution reduced the elimination of fluoride. The carbon was regenerated and reused four times; the removal percentage was decreased from 92 to 31.7%. This adsorption phenomenon showed exothermic behavior. The maximum fluoride uptake capacity of SM*C achieved 2.97 mg/g at 20 mg/L of initial concentration. The modified carbon cartridge of the water filter was successfully employed for fluoride removal from water.

Laser-driven formation of ZnSnO3/CNT heterostructure and its critical role in boosting performance of the triboelectric nanogenerator

Triboelectric nanogenerators (TENGs) as energy harvesters have been extensively investigated due to their ability to convert mechanical energy to electricity through the effective coupling of triboelectrification and electrostatic induction. Herein, we introduce polydimethylsiloxane (PDMS)-based TENG prepared using ZnSnO3 (ZTO) nanostructure on surface-modified carbon nanotubes (SMCs), which shows high power density suitable to different types of practical applications in energy harvesting and self-power system. TENG with 0.3 wt% ZTO-SMC exhibits an output voltage of 665.63 V and a current density of 137.08 mA m−2, corresponding to improvements of 295% and 453%, respectively, with those of a pristine PDMS-based TENG. The peak power density of the TENG is 10.57 W m−2 at a load resistance of 7 MΩ. The formation mechanism of ZTO on the SMCs (ZTO-SMC) and its effect on the TENG performance are demonstrated using density functional theory calculations. It is demonstrated that the enhanced output performance of the PDMS-based TENG using the ZTO-SMC is attributed to the synergetic effect of the enhanced dielectric constant, press-induced polarization, and effective frictional area in the triboelectric layer. This work gives a scientific and technical understanding of not only the formation of heterostructure through interface nanoengineering but also the development of polymer-based TENGs with enhanced triboelectric performance for use in energy harvesting and self-powered systems.

Preparation and application of modified carbon black nanofluid as a novel flooding system in ultralow permeability reservoirs

Conventional flooding systems have very low recovery rates in ultralow permeability reservoirs in virtue of the characteristics of high injection pressure, low permeability and small pores in such reservoirs. In this study, a novel surface-modified carbon black (MCB) nanofluid was prepared as a flooding system to resolve this problem. The preparation process of MCB nanoparticles was divided into three stages: (1) oxidation of carbon black (CB) nanoparticles, (2) acyl chlorination of oxidized carbon black (OCB) nanoparticles and (3) grafting of active groups onto the surface of acyl chloride carbon black (ACB) nanoparticles, and the main synthesis conditions, such as modifier concentration and grafting temperature, were optimized. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis indicated that the factional groups were successfully introduced onto the surface of CB nanoparticles, and the crystallinity of CB nanoparticles decreased gradually during the reaction process. Additionally, the dispersed stability, temperature resistance, salinity tolerance, wettability alteration and oil stripping ability were evaluated so as to obtain the performance of the MCB nanofluid. The results show that the average size of the MCB nanoparticles is approximately 72.3 nm, and the dispersed stability of the MCB nanofluid is much better than that of the CB nanofluid. Compared with the carbon black (CB) nanofluid, the MCB nanofluid shows stronger wettability alteration and oil stripping ability, and can also withstand the high temperature and high salt environment of oil reservoirs. 1 PV of MCB nanofluid can enhance oil recovery by 28.9%. Furthermore, the enhanced oil recovery (EOR) mechanisms for the MCB nanofluid are revealed through analysis of low oil–water IFT (IFT), wettability alteration and Wasan’s theory of structural disjoining pressure. This new type of environment-friendly flooding system injects vitality into the development of ultralow permeability reservoirs.

Modified lanthanide-doped carbon dots as a novel nanochemosensor for efficient detection of water in toluene and its potential application in lubricant base oils

A fast and efficient method was developed for obtaining europium(III)-doped surface-modified carbon dots with a hydrophobic coating. This surface functionalization improved the dispersibility of the nanoparticles in non-polar media, as well as modified the accessibility of water molecules to the europium ions. These two features allowed studying the application of doped carbon dots as moisture nanochemosensor, demonstrating high stability over time of both the photoluminescent signal intensity and the stability of the dispersions. The developed nanochemosensor was used to determine water in toluene with a detection limit of 8.5 × 10−4 M and a quantification limit of 2.4 × 10−3 M. The proposed system matches and even improves other methodologies for water determination in organic solvents; it has a low detection limit and a fast response time (almost instantaneous) and requires neither expensive material nor trained personnel. The results suggest a promising future for the development of a new sensing phase for moisture determination in lubricant base oil.Graphical