Carbon Trends最新文献

{"title":"Optical and electrochemical analysis of nitrogen-doped carbon quantum dots from Moosa balbeesiaana peels for advanced supercapacitor applications","authors":"","doi":"10.1016/j.cartre.2024.100381","DOIUrl":"10.1016/j.cartre.2024.100381","url":null,"abstract":"<div><p>The demand for suitable electrode materials for energy storage devices, driven by increasing energy needs and environmental concerns, has led to the investigation of green synthesis methods. In this study, a composite material (rGO@NCQDs) comprising nitrogen-doped carbon quantum dots (NCQDs) derived from <em>Moosa balbeesiaana</em> peels and reduced graphene oxide (rGO) was synthesized via hydrothermal methods to evaluate its photophysical properties and electrochemical performance for supercapacitors applications. Additionally, the electrochemical behavior of rGO<img>NCQDs combined with Vanadium pentoxide (V₂O₅) was explored.</p><p>Characterization techniques including FTIR spectroscopy revealed typical carbon-based material features in rGO-decorated NCQDs, and rGO<img>NCQDs@V₂O₅ composite. SEM analysis illustrated distinctive surface structures (mushroom-shaped for rGO@NCQDs and flowered-shaped for rGO<img>NCQDs@V2O5), while XRD confirmed crystalline structures with specific sizes.</p><p>Photophysical investigations demonstrated significant Solvatochromic shifts and strong solute-solvent interactions in the composites. Electrochemical studies, including cyclic Voltammetry and Galvanostatic measurements, exhibited promising performance metrics. Specifically, rGO@NCQDs demonstrated a specific capacitance of 134.68 Fg⁻¹ with excellent retention over 5000 charge-discharge cycles. In contrast, rGO<img>NCQDs@V₂O₅ exhibited a maximum specific capacitance of 562.62 Fg⁻¹ at a scan rate of 10 mVs⁻¹ and exceptional cycle stability (96 % retention over 5000 cycles).</p><p>These findings highlight the potential of the synthesized composites as efficient electrode materials for supercapacitors, offering enhanced electrochemical performance and stability. The study underscores the importance of green synthesis approaches in developing functional materials for sustainable energy storage applications.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000622/pdfft?md5=59dbb9941ac8cb7410a76e4329fdfe83&pid=1-s2.0-S2667056924000622-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphorus and nitrogen co-doped-graphene: Stability and catalytic activity in oxygen reduction reaction","authors":"","doi":"10.1016/j.cartre.2024.100379","DOIUrl":"10.1016/j.cartre.2024.100379","url":null,"abstract":"<div><p>This study systematically investigated the stable configurations and oxygen reduction reaction (ORR) catalytic activity of PN co-doped graphene using first-principles methods. We found that PN co-doped graphene substrates are generally highly stable. The adsorption energy of adsorbates is linearly positively correlated with the number of electrons obtained from the substrate. The P atoms serve as catalytic activity sites, the co-doping of N significantly enhances the adsorption energies of intermediate species in the ORR process, facilitating the direct dissociation of O2 and O2H. The solvation effect has a non-negligible impact on the adsorption energy of adsorbates, especially for O2. Due to the excessive adsorption of O, it poisons and inhibits the catalytic activity of P active sites for ORR. However, after O adsorption, the C atoms neighboring the PN impurity atoms in the P-Nn-Gra (n=2,3) substrates exhibit better catalytic activity than that of graphene doped with P/N alone. The P-Nn-defect-Gra (n=2,3,4) substrates are potential catalysts with good HER catalytic activity.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000609/pdfft?md5=517906effb23e217946feaa923edb6f9&pid=1-s2.0-S2667056924000609-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the surface of carbon black via scanning probe microscopy and chemical state analysis","authors":"","doi":"10.1016/j.cartre.2024.100378","DOIUrl":"10.1016/j.cartre.2024.100378","url":null,"abstract":"<div><p>Carbon black (CB) has wide range of industrial applications, including in the manufacturing of automobile tires, rubber products, inks, and plastics. To improve the properties of the target products and establish recycling systems, it must be fully characterized. However, characterization of CB is challenging owing to its structural complexity and the limitation of conventionally used experimental techniques, especially for surface structures at the nanoscale. In this study, we characterized the surface structures of two commercial CB via atomic force and scanning tunneling microscopy. Analysis of well-dispersed aggregates on atomically flat solid surfaces revealed primary particles of diverse sizes. The particle surfaces lacked edges, grooves, and steps that should be observed between stacked graphene sheets, which contradicts the widely accepted crystallite model. Observed images suggest that the graphene sheets exhibit a size distribution, inferring that multiple non-uniformly sized small graphene sheets are stacked turbostratically, with each sheet displaying a localized curvature rather than the ideal planar form. Varying size of sheets and curvature indicate the presence of a decent number of edges terminated with hydrogen and oxygen-containing functional groups. This interpretation was corroborated by conventional spectroscopic techniques: Raman spectroscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption, and infrared absorption spectroscopy.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000592/pdfft?md5=5dd28fb8c149c1be4d4ba84c60257bc5&pid=1-s2.0-S2667056924000592-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141702499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of process parameter on the behavior of pyrocarbon deposition in chemical vapour infiltration (CVI) process","authors":"","doi":"10.1016/j.cartre.2024.100380","DOIUrl":"10.1016/j.cartre.2024.100380","url":null,"abstract":"<div><p>Carbon-carbon composite manufactured by deposition of pyrocarbon (PyC) through chemical vapor infiltration (CVI) has the key issue of being process parametric sensitive which necessitates the detailed study of the effect of process parameters on the rate of PyC deposition. Conventional method of studying the parametric effect by changing one variable at a time keeping the other variables constant has a limitation of more number of experiments and missing the interaction effect among the variables. Here, the effect of process parameters including temperature, pressure, methane gas flow rate, and nitrogen gas flow rate on the mass gain and PyC deposition was studied by Taguchi method, a statistical optimization method, which has the advantage of very few experiments performed at specific pairs of process parameters only. The experiments were performed at three levels of the process parameters. Carbon-Carbon composite material is processed through the CVI process where PyC was deposited on porous carbon fiber preforms at various process conditions as per the Taguchi method. The impact of gas residence time, Reynolds number, Prandtl number, and Peclet number were also investigated. It was observed that the CVI process parameters significantly affect the rate of PyC deposition. Optimized CVI process parameters are essential for achieving a high rate of PyC deposition to reduce the processing time. The findings have revealed that a higher PyC deposition rate arises under high temperatures, pressure, methane gas flow rate, and optimal nitrogen gas flow rate. The effect of the critical interaction of the CVI process parameters on the rate of PyC deposition was also obtained. Based on the experimental studies, process guidelines are proposed for the densification of carbon fibers preform to realize C/C composite products.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000610/pdfft?md5=0ca28e3614c91cfef3a782a1b43c0e7d&pid=1-s2.0-S2667056924000610-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141714813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust correlated magnetic moments in end-modified graphene nanoribbons","authors":"","doi":"10.1016/j.cartre.2024.100377","DOIUrl":"10.1016/j.cartre.2024.100377","url":null,"abstract":"<div><p>We conduct a theoretical examination of the electronic and magnetic characteristics of end-modified 7-atom wide armchair graphene nanoribbons (AGNRs). Our investigation is performed within the framework of a single-band Hubbard model, beyond a mean-field approximation. First, we carry out a comprehensive comparison of various approaches for accommodating di-hydrogenation configurations at the AGNR ends. We demonstrate that the application of an on-site potential to the modified carbon atom, coupled with the addition of an electron, replicates phenomena such as the experimentally observed reduction of the bulk-states (BS) gap. These results for the density of states (DOS) and electronic densities align closely with those obtained through a method explicitly designed to account for the orbital properties of hydrogen atoms. Furthermore, our study enables a clear differentiation between magnetic moments already described in a mean-field (MF) approach, which are spatially confined to the same sites as the topological end-states (ES), and correlation-induced magnetic moments, which exhibit localization along all edges of the AGNRs. Notably, we show the robustness of these correlation-induced magnetic moments relative to end modifications, within the scope of the method we employ.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000580/pdfft?md5=0c3b7f6cf5737a92649d57e3fcc53af8&pid=1-s2.0-S2667056924000580-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141728648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A molecular dynamics investigation of laminar pyrocarbons elasticity up to high-temperatures","authors":"","doi":"10.1016/j.cartre.2024.100376","DOIUrl":"10.1016/j.cartre.2024.100376","url":null,"abstract":"<div><p>The mechanical properties of anisotropic carbons such as the pyrocarbon (pyC) matrices in C/C composites remain poorly documented, especially at elevated temperatures where these materials find most of their applications. We provide here a comprehensive molecular dynamics investigation of the high temperature – up to 4000 K – elastic behavior of six nanoscale pyC models in the context of fast temperature increases, not allowing for major structural modifications such as graphitization. We show that the structure of the most anisotropic and less disordered carbons, like the rough laminar (RL) pyC, is mostly not affected by annealing at the nanosecond timescale, aside from healing unstable defects like two-coordinated atoms at graphene edges. Conversely, highly disordered and less anisotropic carbons like the smooth laminar (SL) pyC show some significant rearrangements at grain boundaries and the development of some limited microporosity. The elastic constants of all highly anisotropic models moderately decrease with increasing temperature, somehow similarly to what is observed for graphite. Elastic constants of the SL pyC show a stronger decrease at high temperature, due to the decrease in density even though all models retain an important degree of stiffness up to 4000 K.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000579/pdfft?md5=b6cfe46a2fe84b7f5ba1f94befec5c5b&pid=1-s2.0-S2667056924000579-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141624035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and magnetic properties of nitrogen-doped carbon materials derived from an ionic liquid precursor","authors":"Moeka Taniguchi ,&nbsp;Hironori Ogata ,&nbsp;Masaru Tachibana","doi":"10.1016/j.cartre.2024.100375","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100375","url":null,"abstract":"<div><p>In this report, effects of pyrolysis conditions on the structure and magnetic properties of nitrogen-doped graphitic carbon materials prepared from 1-Buthyl-3-methyl imidazolium tricyano methanide ( [BMIm] [TCM]) ionic liquids(ILs) were investigated. It was found that nitrogen-containing graphitic carbon was formed under pyrolysis temperature of 400 °C or higher. Under the experimental conditions, the maximum nitrogen content of the obtained sample was C₄N_1.10 at a pyrolysis temperature of 400 °C and it was found that the nitrogen content in the obtained samples decreased with increasing pyrolysis temperature. Ferromagnetism was not observed in all the obtained samples to 2 K. From the value of the orbital diamagnetic susceptibility and XRD, it was found that the obtained sample had the structural characteristics of soft carbon.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000567/pdfft?md5=4de2707345ca5535e98f9ae6d09a16c0&pid=1-s2.0-S2667056924000567-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141479072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogenated graphene support for accelerating alkaline hydrogen evolution reaction","authors":"Siyi Jia ,&nbsp;Mei Hong ,&nbsp;He Xiao ,&nbsp;Xingchen Liu ,&nbsp;Xili Tong","doi":"10.1016/j.cartre.2024.100374","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100374","url":null,"abstract":"<div><p>Up to now, Platinum is still wildly regarded as the state-the-art catalyst toward hydrogen evolution reaction (HER) in acid, however alkaline HER is limited by its poor activity for water dissociation. In this regard, hydrogenated graphene (HG) was emerged as a functional support to boost alkaline HER for Pt catalysts. As a result, the optimized Pt/HG (4.15 % wt Pt) showed a wonderful activity in terms of an overpotential of 54 mV at 10 mA cm⁻² as well as a Tafel slope of 30.28 mV dec⁻¹, superior to the counterparts and even 20 wt% commercial Pt/C. Such a high activity was attributed to the fact HG can optimize electronic state and exposed facet of Pt to accelerate alkaline HER. In addition, density function theory (DFT) calculation revealed the energy barrier for H transfer from HG to Pt only required 0.02 eV, in line with experimental analysis. This work provides a promising strategy to design advanced catalysts toward alkaline HER and beyond.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000555/pdfft?md5=ea905537dfb250a9878ee50b87f00088&pid=1-s2.0-S2667056924000555-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141438583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and thermophysical property characterization of aqueous graphene quantum dot dispersions for air-conditioning applications","authors":"Mahdi Motamedi ,&nbsp;Xiaoran Zheng ,&nbsp;Pramod Koshy ,&nbsp;Robert A. Taylor","doi":"10.1016/j.cartre.2024.100372","DOIUrl":"10.1016/j.cartre.2024.100372","url":null,"abstract":"<div><p>Air-conditioning systems are on track to demand most of the electricity consumed by buildings around the world. The authors propose that dispersing quantum dots into the chilled water loops of air-conditioners represents a path towards improving the efficiency of air-conditioners. As such, the thermophysical properties of carbon-based quantum dot ‘nanofluids’ (e.g., nanoparticles dispersed in liquids) are presented in this study for <em>sub-ambient</em> temperatures (5–15°C)—an under-explored temperature range which requires understanding for air-conditioning applications. This study also explores dispersion stability and materials compatibility—another under-explored area in the literature which is required for commercial uptake. In this study, carbon quantum dots were synthesized via the hydrothermal route and characterized with UV–Vis, FT-IR, Raman spectroscopy, and TEM. Next, the thermophysical properties of specific heat capacity, thermal conductivity, and viscosity of the nanofluids were experimentally measured between 5 and 15°C (not previously reported for aqueous quantum dots). The highest thermal conductivity enhancement was ∼11% (compared to DI water) for 0.3 wt.% at ∼11 °C. Finally, the stability of the fluid was monitored over time and after exposing the fluids to common materials used in air-conditioning systems (e.g., copper, brass, and stainless steel). Unchanged UV–Vis spectra and the lack of sedimentation indicate that the developed dispersions are indeed suitable for chilled water air-conditioning applications.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000531/pdfft?md5=4bf01e67b40def9228ceb3e3dc3e4ec5&pid=1-s2.0-S2667056924000531-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141397837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning insight into inhibition efficiency modelling based on modified graphene oxide of diaminohexane (DAH-GO) and diaminooctane (DAO-GO)","authors":"Kabiru Haruna ,&nbsp;Sani I. Abba ,&nbsp;Jamil Usman ,&nbsp;A.G. Usman ,&nbsp;Abdulrahman Musa ,&nbsp;Tawfik A. Saleh ,&nbsp;Isam H. Aljundi","doi":"10.1016/j.cartre.2024.100373","DOIUrl":"https://doi.org/10.1016/j.cartre.2024.100373","url":null,"abstract":"<div><p>The effective prediction of corrosion inhibition efficiency (%IE) of modified graphene oxides (GOs); diaminohexane-modified graphene oxide (DAH-GO) and diaminooctane-modified graphene oxide (DAO-GO) is vital for advanced material applications. This study employs a dual-modelling scheme to predict the %IE, for this purpose, four stand-alone machine learning (ML) models (Multivariate Regression (MVR), Gaussian Process Regression (GPR), Adaptive Neuro-Fuzzy Inference System (ANFIS), and Neural Network (NN)), and five simple averaging (SA) ensemble paradigms (MVR-SA, GPR-SA, ANFIS-SA, NN-SA, and Decision Tree-SA (DT-SA)). Feature selection processes were carried out to develop three distinct models, leading to a comprehensive comparative analysis. The results demonstrated that the non-linear stand-alone models (GPR, ANFIS, NN) significantly outperform the linear MVR model, with the M2 model configuration yielding the highest performance across all models. Remarkably, GPR-M2 achieved perfect model tuning with zero error rates, indicating its superior predictive capabilities. Ensemble techniques further improved performance, reflecting the experimental data's complexities in %IE modelling. The hierarchical order of performance in the training phase in the testing phase is DT-SA &lt; MVR-SA &lt; ANFIS-SA &lt; NN-SA &lt; GPR-SA. The GPR-SA ensemble emerged as the most accurate technique, substantially enhancing the predictive accuracy of the ensemble models by up to 67.73% in the training phase and 50.71% in the testing phase. These findings suggest the potential of GPR-SA in boosting the performance of ensemble approaches in material science applications. The study recommended a promising future for ML in the development and application of corrosion-inhibitors.</p></div>","PeriodicalId":52629,"journal":{"name":"Carbon Trends","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667056924000543/pdfft?md5=a20d8003d5b921de8be788888ef22dda&pid=1-s2.0-S2667056924000543-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141325300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}