Carbon Nanotube Nanoparticles Research Articles

Application of CNTs – Al2O3/H2O on a Hybrid Nanofluid in Two-Dimensional Unsteady Flow in a Stretching Sheet: Darcy-Forchheimer Model

The fame of carbon nanotube nanoparticles for improving the thermophysical characteristics of fluid molecules has grown recently (Nanoparticles of Carbon nanotubes have attained the fame to enhance the thermophysical properties of fluid molecules). The main objective of this article is to investigate the boundary layer flow of a hybrid nanofluid composed of multi-wall carbon nanotubes (MWCNTs) and single-wall carbon nanotubes (SWCNTs) in combination with alumina and water through a stretching sheet while considering the effects of the magnetic field, thermal radiation, heat dissipation, and slip conditions. Additionally, comparisons and studies of the effects of MWCNTs and SWCNTs nanoparticles on the boundary layer are conducted. The dimensionless similarity transformation is used by the bvp4c algorithm in the MATLAB solver to calculate the numerical solutions of the dimensionless ordinary differential equations. Graphs and tables are used to show the associated model’s physical parameters. In addition, the hybrid nanofluid’s flow pattern is generally slowed down by the magnetic, porosity, and inertia coefficient factors. The rate of heat transfer was boosted by using a larger volume fraction of MWCNTs and SWCNTs.

Investigating the Impact of Carbon Nanotube Nanoparticle Exposure on Testicular Oxidative Stress and Histopathological Changes in Swiss albino Mice.

Carbon nanotubes (CNTs) possess remarkable properties that make them valuable for various industrial applications. However, concerns have arisen regarding their potential adverse health effects, particularly in occupational settings. The main aim of this research was to examine the effects of short-term exposure to multiwalled carbon nanotube nanoparticles (MWCNT-NPs) on testicular oxidative stress in Swiss albino mice, taking into account various factors such as dosage, duration of exposure, and particle size of MWCNT-NP. In this study, 20 mice were used and placed into six different groups randomly. Four of these groups comprised four repetitions each, while the two groups served as the vehicle control with two repetitions each. The experimental groups received MWCNT-NP treatment, whereas the control group remained untreated. The mice in the experimental groups were exposed to MWCNT-NP for either 7 days or 14 days. Through oral administration, the MWCNT-NP solution was introduced at two distinct dosages: 0.45 and 0.90 μg, whereas the control group was subjected to distilled water rather than the MWCNT-NP solution. The investigation evaluated primary oxidative balance indicators-glutathione (GSH) and glutathione disulfide (GSSG)-in response to MWCNT-NP exposure. Significantly, a noticeable reduction in GSH levels and a concurrent increase in GSSG concentrations were observed in comparison to the control group. To better understand and explore the assessment of the redox status, the Nernst equation was used to calculate the redox potential. Intriguingly, the calculated redox potential exhibited a negative value, signifying an imbalance in the oxidative state in the testes. These findings suggest that short-term exposure to MWCNT-NP can lead to the initiation of testicular oxidative stress and may disrupt the male reproductive system. This is evident from the alterations observed in the levels of GSH and GSSG, as well as the negative redox potential. The research offers significant insights into the reproductive effects of exposure to MWCNTs and emphasizes the necessity of assessing oxidative stress in nanomaterial toxicity studies.

RuCo@P Core-Shell Nanoparticles Filled with Carbon Nanotubes for Highly Effective Catalytic Hydrolysis of Ammonia Borane

The doping of nonmetals in multiphase metal catalysts can effectively improve the catalytic performance and reduce the catalyst cost. In this study, we synthesized transition metal phosphide (RuCo@P/CNT) catalysts loaded on carbon nanotubes (CNT) using sodium borohydride (NaBH4) as the reducing agent. The microstructure and phase composition of RuCo@P/CNT nanoparticles were investigated using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and BET. RuCo@P/CNT nanoparticles show superior catalytic activity and cycle stability in the catalytic ammonia borane hydrolysis process compared to Ru/CNT and RuCo/CNT nanoparticles, retaining 65.74% of their initial catalytic activity after 5 reaction cycles. The test yielded values for turnover frequency and activation energy of 327.33 min-1 and 36.77 kJ·mol-1, respectively. Additionally, a kinetic isotope effect value of 2.61 for H2O/D2O showed that O-H bond breaking in proportional acceptor water is the decisive step in the dehydrogenation of ammonia borane, and based on this discovery, a specific mechanism for the catalytic hydrolysis of AB by RuCo@P NPs is postulated.

Spatial Confinement of Pt Nanoparticles in Carbon Nanotubes for Efficient and Selective H2 Evolution from Methanol.

H2 generation from methanol-water mixtures often requires high pressure and high temperature (200-300°C). However, CO can be easily generated and poison the catalytic system under such high temperature. Therefore, it is highly desirable to develop the efficient catalytic systems for H2 production from methanol at room temperature, even at sub-zero temperatures. Herein, carbon nanotube-supported Pt nanocomposites are designed and synthesized as high-performance nano-catalysts, via stabilization of Pt nanoparticles onto carbon nanotube (CNT), for H2 production upon methanol dehydrogenation at sub-zero temperatures. Therein, the optimal Pt/CNT nanocomposite presents the superior catalytic performance in H2 production upon methanol dehydrogenation at the expense of B2(OH)4, with the TOF of 299.51min-130 oC. Compared with other common carriers, Pt/CNT exhibited the highest catalytic performance in H2 production, emphasizing the critical role of CNT in methanol dehydrogenation. The confinement of Pt nanoparticles by CNTs is conducive to inhibiting the aggregation of Pt nanoparticles, thereby significantly increasing its catalytic performance and stability. The kinetic study, detailed mechanistic insights, and density functional theory (DFT) calculation confirm that the breaking of O─H bond of CH3OH is the rate-controlling step for methanol dehydrogenation, and both H atoms of H2 are supplied by methanol. Interestingly, H2 is also successfully produced from methanol dehydrogenation at -10°C, which absolutely solves the freezing problem in the H2 evolution upon water-splitting reaction.

3D-Printed Carbon-Based Conformal Electromagnetic Interference Shielding Module for Integrated Electronics

Highlights3D printable functional inks incorporated with graphene and carbon nanotube nanoparticles were well-formulated by manipulating their rheological performanceThe frame with ultralight structure (0.076 g cm−3) and high-efficiency electromagnetic interference shielding (61.4 dB) was assembled3D-printed c-SE module was in situ integrated onto the electronics, affording multiple functions of electromagnetic compatibility and thermal dissipation.

In-based coordination polymer-derived carbon nanoribbons with abundant CoP nanoparticles in carbon nanotubes for water oxidation.

The sluggish oxygen evolution reaction (OER) in overall electrocatalytic water splitting poses a significant challenge in hydrogen production. A series of transition metal phosphides are emerging as promising electrocatalysts, effectively modulating the charge distribution of surrounding atoms for OER. In this study, a highly efficient OER electrocatalyst (CoP-CNR-CNT) was successfully synthesized through the pyrolysis and phosphatization of a Co-doped In-based coordination polymer, specifically InOF-25. This process resulted in evenly dispersed CoP nanoparticles encapsulated in coordination polymer-derived carbon nanoribbons. The synthesized CoP-CNR-CNT demonstrated a competitive OER activity with a smaller overpotential (η10) of 295.7 mV at 10 mA cm-2 and a satisfactory long-term stability compared to the state-of-the-art RuO2 (η10 = 353.7 mV). The high OER activity and stability can be attributed to the high conductivity of the carbon network, the abundance of CoP particles, and the intricate nanostructure of nanoribbons/nanotubes. This work provides valuable insights into the rational design and facile preparation of efficient non-precious metal-based OER electrocatalysts from inorganic-organic coordination polymers, with potential applications in various energy conversion and storage systems.

Sensitivity analysis on optimizing heat transfer rate in hybrid nanofluid flow over a permeable surface for the power law heat flux model: Response surface methodology with ANOVA test

<abstract> <p>Joule dissipation has an important role in the conversion of mechanical energy to heat within a fluid due to the internal friction and viscosity. Moreover, Darcy friction is a measure of the resistance to flow in a porous medium. In response to the efficient heat transfer performance, a robust statistical approach was established to optimize the heat transfer rate in a two-dimensional flow of a nanofluid over a permeable surface embedded with a porous matrix. The electrically conducive fluid affected the flow phenomena to include a carbon nanotube nanoparticle in the conventional liquid water for the enhanced heat transfer properties; additionally, the power-law heat flux model was considered. Appropriate transformation rules were adopted to obtain a non-dimensional system that brought a developed model equipped with several factors. The traditional numerical technique (i.e., shooting based Runge-Kutta) was proposed to handle the coupled nonlinear system. Furthermore, the statistical response surface methodology (RSM) was adopted to obtain an efficient optimized model for the heat transportation rate of the considered factors. An analysis of variance (ANOVA) was utilized to validate the result of the regression analysis. However, it was evident that the nanoparticle concentrations were useful to augment the fluid velocity and the temperature distributions; the statistical approach adopted for the heat transfer rate displayed an optimized effect as compared to a conventional effect.</p> </abstract>

Molecularly imprinted polymer nanoparticle-carbon nanotube composite electrochemical gas sensor for highly selective and sensitive detection of methanol vapour.

An electrochemical gas sensor has been fabricated using molecularly imprinted polymer nanoparticles (nanoMIPs) and multiwalled carbon nanotubes on screen-printed electrodes. Methanol vapour was chosen as the target due to its toxicity as its suitability as a model for more harmful pollutant gases. The sensor functions under ambient conditions and in the required concentration range, in contrast to all previous MIP-based gas sensors for methanol. The sensitivity of the sensor was greatly improved by the addition of multiwall carbon nanotubes, resulting in a limit of detection of approximately 10 ppm. The nanoMIPs provide an inherent selectivity for the target inherent in its design. Selectivity studies were performed with structurally analogous alcohols at various concentrations, demonstrating selectivity for methanol 12.1 times that for ethanol at 2 mmol dm-3 and 4.2 times that for ethanol at 1 mmol dm-3. Interactions with isopropanol and n-propanol were found to be non-specific, and the response to water was negligible. This demonstrates an improvement over previous methanol gas sensors based on molecularly imprinted polymers. No response was observed with carbon nanotubes alone, and no selectivity was observed with non-imprinted equivalents of the nanoMIP sensor. The resulting device is by far the most practical MIP-based instrument for methanol gas sensing thus far described in the literature, being the only example capable of functioning at the necessary methanol vapour concentrations and at the required temperature and humidity. With the selectivity and sensitivity described and the simple design, the developed device provides a substantial advance in the field of molecularly imprinted gas sensors.

Incorporating Copper and Carbon Nanotube Nanoparticles into Phase Change Materials for Enhanced Thermal Management in Batteries

The primary objective of this study was to explore the impact of integrating nano-additives on heat transfer enhancement within an LHTES (Latent Heat Thermal Energy Storage) system. Our findings revealed that introducing a minimal amount of nano-materials (less than 5.0 vol%) into the Phase Change Material (PCM) led to a remarkable alignment between experimental correlations and mixture models. Furthermore, employing the mixing model allowed for the accurate prediction of outcomes. In the current context of scientific research, there is a strong endorsement for the widespread adoption of Electric Vehicles (EVs) as a sustainable alternative to Internal Combustion Engines (ICEs), crucial for advancing decarbonization and mitigating climate-related crises. Lithium-ion batteries are the predominant choice for EVs and various electrical devices. However, the operational challenges posed by high temperatures, impacting their lifespan, charge/discharge cycles, and the risk of thermal runaway, necessitate effective thermal management systems. Given this background, our study focuses on simulating the heat dissipation of a single cylindrical Li-ion battery cell employing a Nano-enhanced Phase Change Material (NePCM)-based cooling system. We also introduce a novel fin design in this work. Through comprehensive analysis, we examine the performance of battery modules utilizing PCM and NePCM at different discharge rates, both with and without the newly proposed fin design. Our research demonstrates that the incorporation of fins and nanoparticles into PCM significantly enhances heat transfer and reduces the charging time compared to the base PCM. Notably, carbon-based nanoparticles outshine their metal-based counterparts in terms of melting rate and maintaining a uniform temperature profile within the battery.

Agarose‐sodium alginate hydrogel beads enhanced with zeolitic imidazolate frameworks/multiwalled carbon nanotubes nanoparticles for efficient adsorption and selective separation of methylene blue

AbstractThe urgent problem to solve is how to design a kind of green and porous adsorbent that can effectively remove dye pollutants in the field of the sewage treatment. The objectives of this investigation are to incorporate zeolitic imidazolate frameworks‐8 (ZIF‐8) particles in situ onto the surface of multiwalled carbon tubes (MWCNTs) and integrate them into an agarose‐sodium alginate (ASA) double network hydrogel. The resulting composite hydrogel beads, denoted as MWCNTs/ZIF‐8/ASA (MZASA), are synthesized using calcium ion crosslinking. The addition of agarose is employed to create a dual‐crosslinked hydrogel, thereby enhancing the mechanical properties of the ASA hydrogel. By incorporating MWCNTs/ZIF‐8 nanoparticles, the surface area of the MZASA hydrogel is augmented, leading to an enhancement in dye adsorption capacity. In batch sorption mode, the maximum absorbency of the resulting hydrogel beads for methylene blue (MB) is 493.799 mg/g, which was a third greater than that of pure SA beads. Absorption of MB obeys the pseudo‐second‐order kinetic model and Langmuir isotherm model, suggesting monolayer chemisorption adsorption. Analysis of the thermodynamics proves that the entire adsorption process is exothermic and spontaneous. Moreover, the MZASA hydrogel beads show high selectivity for cationic dyes in the mixed dye test. Hence, the synthesized MZASA hydrogel beads serve as a highly effective, innovative, and reusable adsorbent for eliminating cationic dyes from water‐based solutions.

Confined PbO2 nanoparticles in carbon nanotubes on boron-doped diamond substrate for highly efficient chlortetracycline degradation

Realizing highly efficient catalysis with high stability in complex chemical environments remains a major challenge for advanced oxidation processes. Here, confined lead dioxide (PbO2) nanoparticles in carbon nanotubes (CNTs) on boron-doped diamond (BDD) substrate is designed and fabricated as a heterogeneous catalyst for antibiotic treatment, achieving ultra-efficient degradation of chlortetracycline (CTC) with high reaction rate and stability. The maximum degradation rate of CTC reaches 98.8 % in 120 min, and it remains 91.0 % after ten cycles, which are significantly higher than that proposed by the contrast catalysts. The excellent degradation performance of this heterogeneous catalyst is mainly attributed to three factors: (i) the prepared PbO2 nanoparticles with an average size of 5 nm are confined in CNTs, providing more active sites and higher electron transfer rate; (ii) secondary pollution and catalyst deactivation of PbO2 are avoided by protecting CNTs; (iii) BDD shows strong capacity for mineralizing organic compounds related to the high oxygen evolution reaction potential. This finding provides a novel strategy for advanced oxidation processes in environmental remediation.

Hydromagnetic Flow of Casson Fluid Carrying CNT and Graphene Nanoparticles in Armory Production

Carbon nanotubes (CNTs) and graphenes possess the properties that make them the future of armory in the military. Bullet-proof vests, for instance, are indispensable components of any military arsenal whose maintenance cost and weight can be drastically reduced if the materials are changed to CNT and graphenes. The purpose of this study is to investigate heat and mass transport phenomena in the hydromagnetic flow of Casson fluid suspending carbon nanotubes and graphene nanoparticles in armory production. An appropriate model is developed, taking into account the Buongiorno model and the effect of heat radiation. Using similarity variables, the model is reformulated into a dimensionless form. The numerical solution to the dimensionless model is obtained using the three-stage Lobatto IIIa finite difference approach, which is programmed into the MATLAB bvp4c package. The study reveals that an increase in the Casson fluid parameter leads to a decrease in the velocity profiles. There is a 78.41% reduction in skin friction when results are compared with the CNT-water nanofluid.

Experimental investigation of usage of POE lubricants with Al2O3, graphene or CNT nanoparticles in a refrigeration compressor.

In this study, the use of nanolubricants containing Al2O3, graphene, and carbon nanotubes (CNTs) at different mass fractions in a refrigeration compressor was experimentally investigated. The required electrical power of the compressor was measured to determine the effect of the use of nanolubricants. Nanoparticles used in the preparation of nanolubricants were gradually added to the lubricant to determine the optimum nanoparticle mass fraction for each nanoparticle type. Thus, it was found that the compressor operated safely and efficiently with nanolubricants. Furthermore, the optimum mass fractions were determined to be 0.750% for Al2O3, 0.250% for graphene, and 0.250% for CNTs for operating conditions of this study. As a result, the required electrical power of the compressor decreased by 6.26, 6.82, and 5.55% with the addition of Al2O3, graphene, and CNT nanoparticles at optimum mass fractions of 0.750, 0.250, and 0.250% to the lubricant, respectively, compared to the compressor using pure oil. Moreover, density and dynamic viscosity of the nanolubricant samples used in the experiments were also measured, and their kinematic viscosity, which is an important parameter for lubricants, was calculated. It was determined that the kinematic viscosity continuously increased with increasing nanoparticle fraction. In conclusion, nanolubricants containing nanoparticles above the optimum mass fraction increase the required electrical power of the compressor. It is concluded that nanoparticle fractions should not be used above the optimum value in nanolubricant applications.

Chitosan-Carbon nanotube Composite: An approach for controlled release of Quercetin, Modified with carboxymethyl Cellulose, for potential Anti-Cancer therapy

Nanoparticles as medicine has made progress in the field of medicine and pharmacy by improving the performance of the drug and reducing its consumption. Different materials such as natural and synthetic polymers, metal particles, lipids, etc. are used to produce nanoparticles, which can have different shapes (morphologies) and sizes according to their production and synthesis method. According to the things mentioned in the present study, a new nanocarrier based on hydrogel nanocomposite containing chitosan (CS), carboxymethyl cellulose (CMC) and carbon nanotubes (CNTs) was used to load the drug quercetin (QC), which has antioxidant, antiviral, and anticancer properties. Based on the experiments conducted in the current research and Field emission scanning electron microscopy (FESEM) images and zeta potential analysis, all of them investigate the nanocomposite surface and nanocarrier stability, and the existence of nanocomposite materials is also confirmed by X-ray diffraction analysis (XRD) and Fourier-transform infrared spectroscopy(FTIR) analyses. In the current study, the First-order model analyzes and characterizes the release data far better than the zero and Second-order models do, as shown by the values of R2. Also, the introduction of CNTs improved the drug loading by 48.0% and increased its encapsulation by 86.5%. Also, in the current study, the cytotoxicity of nanocarriers with QC was measured by MTT analysis, and by examining the results, it was found that the significant cytotoxicity of CS/CMC/CNTs/QC on MCF-7 cell line is caused by it compared to free QC. The inhibitory effect of CNT nanoparticles and improving the release behaviour of nanocarriers. Increasing the sustained releaseof QC from CS/CMC/CNTs/QC improves cell apoptosis and decreases viability, and also the late apoptotic cells ratio in CS/CMC/CNTs/QC in the cell apoptosis assay is superior to the cell size samples, which may be due to the controlled and slow release of QC from CS/CMC/CNTs/QC.

A Self-Healing Thermoset Epoxy Modulated by Dynamic Boronic Ester for Powder Coating.

Thermoset powder coatings exhibit distinctive characteristics such as remarkable hardness and exceptional resistance to corrosion. In contrast to conventional paints, powder coatings are environmentally friendly due to the absence of volatile organic compounds (VOCs). However, their irreversible cross-linking structures limit their chain segment mobility, preventing polymers from autonomously repairing cracks. Dynamic cross-linking networks have garnered attention for their remarkable self-healing capabilities, facilitated by rapid internal bond exchange. Herein, we introduce an innovative method for synthesizing thermoset epoxy containing boronic ester moieties which could prolong the life of the powder coating. The epoxy resin system relies on the incorporation of two curing agents: one featuring small-molecule diamines with boronic bonds and the other a modified polyurethane prepolymer. A state of equilibrium in mechanical properties was achieved via precise manipulation of the proportions of these agents, with the epoxy composite exhibiting a fracture stress of 67.95 MPa while maintaining a stable glass transition temperature (Tg) of 51.39 °C. This imparts remarkable self-healing ability to the coating surface, capable of returning to its original state even after undergoing 1000 cycles of rubbing (using 1200-grit abrasive paper). Furthermore, the introduction of carbon nanotube nanoparticles enabled non-contact sequential self-healing. Subsequently, we introduce this method into powder coatings of different materials. Therefore, this work provides a strategy to develop functional interior decoration and ensure its potential for broad-ranging applications, such as aerospace, transportation, and other fields.

Molybdate-doped sulfonated-polyaniline (SPni.Mo) grafted CNT nano-particles for fabrication of a dual-functional epoxy composite coating with durable corrosion resistance function

Carbon nanotubes nano-particles modified with organic-inorganic hybrid inhibitors, i.e., sulfonated polyaniline doped with molybdate (OMC.SPni.Mo) was designed to improve the anti-corrosion capability of carbon nanotubes for application in an epoxy polymer coating. The ability to release the inhibitors from the OMC.SPni.Mo surface in the saline solution at different pHs was demonstrated by EIS and ICP techniques. Epoxy resin reinforced with this nanohybrid, (OMC.SPni.Mo.EPoxy) was applied to the steel plate. EIS test outcomes revealed that after 90 days of immersion, the OMC.SPni.Mo.EPoxy sample did not show a significant change in the Log|Z|10mHz (≥10.5 Ωcm2). The OMC.SPni.Mo.EPoxy coating active corrosion mitigation after scratching was evaluated by the EIS technique and accelerated salt spray test. In this case, the total resistance reached 106.200 Ω cm2, which is 118% more than the pure coating. The improvement of the coating resistance is due to the film development in the scratched area and the prevention of corrosive agents from reaching the metal surface. The enhancement of the barrier protection against the progress of harmful ions in the coating-substrate interface and the adhesion of the OMC.SPni.Mo.EPoxy coating to the substrate compared to the sample coated with epoxy was presented by cathodic delamination and pull-off tests.

A thermal case study of three dimensional MHD rotating flow comprising of multi-wall carbon nanotubes (MWCNTs) for sustainable energy systems

The carbon nanotubes (CNTs) possess unique properties due to their structural mechanism. The CNTs comprise of exceptional electrical, mechanical and thermal attributes. This paper aims to interpret the correlation of carbon nanotube nanoparticles with motile microorganisms in a rotating magnetohydrodynamic flow with respect to slip as well as convective boundary conditions. Multi-wall carbon nanotubes (MWCNTs) are incorporated as nanoparticles whereas water (H2O) as host fluid. The dimension free appearance of governing differential equations is caused by the similarity transformation. Afterward, the combination of order reduction and finite differences is used to determine the approximate solution of the problem. The consequences of problem parameters for temperature, velocity, Nusselt number and skin friction are deliberated through tables and graphs. The code efficiency is assessed by equating the results, under limiting cases, with the previous ones and found to be in an exceptional agreement. The temperature seems to be elevating with the influence of Biot number. On the other hand, a decreasing trend in the velocity profile is noticed when we increase the parametric values of rotation as well as slip parameter. The Peclet number is one of the factor that reduces the microbe's density distribution within the boundary layer regions.

Energy storage investigation of solar pond integrated with PCM and nanoparticles during winter season in Chennai

Solar energy is a highly regarded renewable energy sources that are attracting substantial attention owing to its potential to alleviate climate change and provide sustainable energy. Solar ponds are one approach to collect solar energy by capturing and storing thermal energy inside a pond. However, the effectiveness of solar ponds has been hampered by reasons such as heat loss, evaporation, and inadequate heat transmission. Researchers have investigated the use of phase change materials (PCMs) and nano-additives to improve the performance of solar ponds in order to overcome these issues.Large amounts of heat can be stored and released by substances known as phase change materials as they transition between two states. By adding PCMs into solar ponds, heat may be retained throughout the day and released at night when the sun is not shining. Alternatively, nano-additives have the potential to enhance the efficiency of a solar pond by improving the heat transfer properties of the fluid present in it.To measure the thermal efficiency of the solar pond, multiple phases of an experiment have been undertaken to establish the degree of thermal efficiency. During the experiment, various parameters were employed to measure and track the temperature variations in the lower convective zone (LCZ) of the solar pond. These measurements were recorded on a daily, weekly, and hourly basis, taking into account the depth of the solar pond as a determining factor. There was also an experiment carried out using micro PCMs and paraffin waxes (PCMs) that were combined into the matrix. In this study, nanoparticles with high thermal conductivity, such as carbon nanotubes (CNTs), and hybrid nanoparticles, such as AgTiO2, were utilized.The solar pond without phase change material (PCM) had an average temperature of 45 °C in the lower convective zone (LCZ). When PCM was added to the solar pond, the maximum temperature in the LCZ increased by 2 °C compared to the previous 24 h. Furthermore, when carbon nanotube (CNT) nanoparticles were incorporated into the solar pond with PCM at the base, the temperature was observed to be 1.3 °C higher compared to a typical solar pond that only used PCM for heat storage. In another scenario, the solar pond with PCM and a combination of CNT and AgTiO2 nanoparticles had an average temperature of 52.5 °C in the LCZ during the first week of observation.

Confined FeNi alloy nanoparticles in carbon nanotubes for photothermal oxidative dehydrogenation of ethane by carbon dioxide

Oxidative dehydrogenation of ethane with CO2 (ODEC) is an attractive reaction for reduction of carbon footprints and ethene production. In this work, we present photothermal catalysis on confined bimetal catalysts for ODEC. Carbon nanotubes confined non-noble bimetal alloy (i.e., CoNi@CNTs and FeNi@CNTs) catalysts were prepared and FeNi@CNTs showed effective performance in photothermal catalytic ODEC to ethene. Experiments and simulations reveal that UV and visible lights (420 – 490 nm) are responsible for ODEC and non-oxidative dehydrogenation of ethane, respectively, to ethene. Additionally, ODEC to ethene is preferred to C-C cracking to methane on FeNi@CNTs in light (> 490 nm)-induced thermocatalysis. The photothermal effect turns more significant when introduced into thermocatalytic ODEC (500 °C), with ethene generation at one order of magnitude. This work advances new mechanism of photo-mediated catalysis and sheds light on utilization of full-spectrum solar energy and non-noble metallic catalysts for ethene production and CO2 recycling at moderate conditions.

Comparative combustion, emission, and performance analysis of a diesel engine using carbon nanotube (CNT) blended with three different generations of biodiesel.

Nano-additives are being employed in successive generations of biodiesels to increase the performance characteristics and output of diesel engines. In this study, the impact of mixing carbon nanotubes (CNT) with three different generations of biodiesel in a diesel engine is assessed. With 100 ppm of CNT nanoparticles mixed together, pure biodiesels made from first-generation oil (soybean), second-generation oil (neem), and third-generation oil (Nannochloropsis oculata microalgae) are used for the analysis. With an engine load ranging from 0 to 100%, a one-cylinder, four-stroke, direct injection diesel engine is employed. The engine has a water-cooling system, a compression ratio of 17.5:1, and a fuel injection angle of 23° before TDC. The evaluated engines' improved performance and lower emissions serve as proof of the outcomes. The results are evidenced by the lower emissions and higher performance of the tested engines. The biodiesel containing CNT nanoparticles enhanced the cylinder pressure by 0.8-10.69%, the heat release rate (HRR) by 6.38-21.69%, and the brakethermal efficiency (BTE) by 0.32-1.62%. Subsequently, it reduced the brake-specific fuel consumption (BSFC) by 2.53-8.13%, the brake-specific energy consumption (BSEC) by 1.07-3.77%, the smoke opacity (BSN) by 6.26-12.85%, the particulatematter (PM) emissions by 11.04-18.33%, and the carbon dioxide (CO2) emissions by 2.53-8.14% at full engine load. However, an increase in 13.62-18.37% nitrogen emissions (NOx) emissions is also observed with the addition of CNT at 100% load. The investigation supports the use of CNT nano-additives in diesel engines for improved performance and reduced emissions.