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Haripriya M, Manimekala T, Dharmalingam G, Minakshi M, Sivasubramanian R. Asymmetric Supercapacitors Based on ZnCo 2O 4 Nanohexagons and Orange Peel Derived Activated Carbon Electrodes. Chem Asian J 2024; 19:e202400202. [PMID: 38687089 DOI: 10.1002/asia.202400202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/21/2024] [Accepted: 04/29/2024] [Indexed: 05/02/2024]
Abstract
Herein, the performance of asymmetric supercapacitors (ASC) fabricated using ZnCo2O4 (ZCO) nano-hexagons and orange peel-derived activated carbon (OPAC) as electrodes was studied. ZCO was prepared by a double hydroxide method and OPAC was prepared from orange peel followed by KOH activation. For ZCO, the calcination temperature was determined using TGA analysis. The XRD showed the presence of a cubic spinel structure. The chemical structure was analyzed using XPS, FTIR, and Raman spectroscopy respectively. For OPAC, the presence of an amorphous nature was inferred; FTIR and Raman studies indicate the presence of functional groups and defect structure in the material. The presence of ZCO nano-hexagons was observed from SEM and TEM respectively. For OPAC, an interconnected pore structure was observed from the SEM image. The specific capacitance for ZCO and OPAC was found to be 194 F.g-1 and 159 F.g-1 at a current density of 0.25 A.g-1. Further, an ASC was fabricated using ZCO as a positive and OPAC as a negative electrode in 2M KOH-soaked separator. A cell voltage of 1.2 V was achieved and the specific capacitance was calculated to be 64 F.g-1 at 0.25 A.g-1. Further, the cyclic stability and the changes at the electrode/electrolyte interface were studied.
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Affiliation(s)
- M Haripriya
- Department of Chemistry, NSS College, Nemmara, Palakkad, Kerala, 678508), India
| | - T Manimekala
- Department of Nanoscience and Technology, Electrochemical Sensors and Energy Materials Laboratory, PSG Institute of Advanced Studies, Coimbatore, Tamilnadu, 641004), India
| | - Gnanaprakash Dharmalingam
- Department of Nanoscience and Technology, Plasmonics Nanomaterials Laboratory, PSG Institute of Advanced Studies, Coimbatore, Tamilnadu, 641004), India
| | - Manickam Minakshi
- College of Science, Health, Engineering and Education, Murdoch University, Perth, WA, 6150), Australia
| | - R Sivasubramanian
- Department of Chemistry, School of Physical Sciences, Amrita Vishwa Vidyapeetham, Amaravati, Andhra Pradesh, 522503, India
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Sahiner M, Demirci S, Sahiner N. Polydopamine Coating of Graphitic Carbon Nitride, g-C 3N 4, Improves Biomedical Application. Biomedicines 2024; 12:1151. [PMID: 38927358 PMCID: PMC11201011 DOI: 10.3390/biomedicines12061151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/07/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
Graphitic carbon nitride (g-C3N4) is an intriguing nanomaterial that exhibits photoconductive fluorescence properties under UV-visible light. Dopamine (DA) coating of g-C3N4 prepared from melamine was accomplished via self-polymerization of DA as polydopamine (PDA). The g-C3N4 was coated with PDA 1, 3, and 5 times repeatedly as (PDA@g-C3N4) in tris buffer at pH 8.5. As the number of PDA coatings was increased on g-C3N4, the peak intensity at 1512 cm-1 for N-H bending increased. In addition, the increased weight loss values of PDA@g-C3N4 structures at 600 °C from TGA thermograms confirmed that the coating was accomplished. The band gap of g-C3N4, 2.72 eV, was reduced to 0.87 eV after five coatings with PDA. A pristine g-C3N4 was found to have an isoelectric point (IEP) of 4.0, whereas the isoelectric points of 1PDA@g-C3N4 and 3PDA@g-C3N4 are close to each other at 3.94 and 3.91, respectively. On the other hand, the IEP of 5PDA@g-C3N4 was determined at pH 5.75 assuming complete coating with g-C3N4. The biocompatibility of g-C3N4 and PDA@g-C3N4 against L929 fibroblast cell lines revealed that all PDA@g-C3N4 coatings were found to be biocompatible up to a 1000 mg/mL concentration, establishing that PDA coatings did not adversely affect the biocompatibility of the composite materials. In addition, PDA@g-C3N4 was screened for antioxidant potential via total phenol content (TPC) and total flavonoid content assays and it was found that PDA@g-C3N4 has recognizable TPC values and increased linearly with an increased number of PDA coatings. Furthermore, blood compatibility of pristine g-C3N4 is enhanced considerably upon PDA coating, affirmed by hemolysis and the blood clotting index%. Additionally, α-glucosidase inhibitory properties of PDA@g-C3N4 structures revealed that 67.6 + 9.8% of this enzyme was evenly inhibited by 3PDA@g-C3N4 structure.
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Affiliation(s)
- Mehtap Sahiner
- Department of Bioengineering, Faculty of Engineering, Canakkale Onsekiz Mart University Terzioglu Campus, 17100 Canakkale, Turkey;
| | - Sahin Demirci
- Department of Chemistry, Faculty of Sciences, Canakkale Onsekiz Mart University Terzioglu Campus, 17100 Canakkale, Turkey;
| | - Nurettin Sahiner
- Department of Chemistry, Faculty of Sciences, Canakkale Onsekiz Mart University Terzioglu Campus, 17100 Canakkale, Turkey;
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, 12901 Bruce B Downs B. Downs Blv., MDC 21, Tampa, FL 33612, USA
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Sinharoy A, Lee GY, Chung CM. Optimization of Calcium Fluoride Crystallization Process for Treatment of High-Concentration Fluoride-Containing Semiconductor Industry Wastewater. Int J Mol Sci 2024; 25:3960. [PMID: 38612770 PMCID: PMC11011877 DOI: 10.3390/ijms25073960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 03/30/2024] [Accepted: 04/01/2024] [Indexed: 04/14/2024] Open
Abstract
This study utilized a fluidized bed reactor (FBR) for fluoride removal from high-concentration fluoride-ion-containing simulated semiconductor industry wastewater and recovered high-purity CaF2 crystals. The effects of hydraulic retention time (HRT), pH, Ca2+ to F- ratio, upflow velocity, seed size and seed bed height were investigated by performing lab-scale batch experiments. Considering fluoride removal and CaF2 crystallization efficiency, 5 h HRT, pH 6, seed height of 50 cm and [Ca2+]/[F-] ratio of 0.55 (mol/mol) were found to be optimum. The effect of the interaction between the important process parameters on fluoride removal was further analyzed using response surface methodology (RSM) experimental design. The results showed that all the individual parameters have a significant impact (p = 0.0001) on fluoride removal. SEM-EDX and FTIR analysis showed the composition of the crystals formed inside FBR. HR-XRD analysis confirmed that the crystalline structure of samples was mainly CaF2. The results clearly demonstrated the feasibility of silica seed material containing FBR for efficient removal and recovery of fluoride as high-purity calcium fluoride crystals.
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Affiliation(s)
| | | | - Chong-Min Chung
- Department of Environmental Science & Biotechnology, Jeonju University, Jeonju 55069, Republic of Korea; (A.S.); (G.-Y.L.)
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Komal Zafar H, Zainab S, Masood M, Sohail M, Shoaib Ahmad Shah S, Karim MR, O'Mullane A, Ostrikov KK, Will G, Wahab MA. Recent Advances on Nitrogen-Doped Porous Carbons Towards Electrochemical Supercapacitor Applications. CHEM REC 2024; 24:e202300161. [PMID: 37582638 DOI: 10.1002/tcr.202300161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/19/2023] [Indexed: 08/17/2023]
Abstract
Due to ever-increasing global energy demands and dwindling resources, there is a growing need to develop materials that can fulfil the World's pressing energy requirements. Electrochemical energy storage devices have gained significant interest due to their exceptional storage properties, where the electrode material is a crucial determinant of device performance. Hence, it is essential to develop 3-D hierarchical materials at low cost with precisely controlled porosity and composition to achieve high energy storage capabilities. After presenting the brief updates on porous carbons (PCs), then this review will focus on the nitrogen (N) doped porous carbon materials (NPC) for electrochemical supercapacitors as the NPCs play a vital role in supercapacitor applications in the field of energy storage. Therefore, this review highlights recent advances in NPCs, including developments in the synthesis of NPCs that have created new methods for controlling their morphology, composition, and pore structure, which can significantly enhance their electrochemical performance. The investigated N-doped materials a wide range of specific surface areas, ranging from 181.5 to 3709 m2 g-1 , signifies a substantial increase in the available electrochemically active surface area, which is crucial for efficient energy storage. Moreover, these materials display notable specific capacitance values, ranging from 58.7 to 754.4 F g-1 , highlighting their remarkable capability to effectively store electrical energy. The outstanding electrochemical performance of these materials is attributed to the synergy between heteroatoms, particularly N, and the carbon framework in N-doped porous carbons. This synergy brings about several beneficial effects including, enhanced pseudo-capacitance, improved electrical conductivity, and increased electrochemically active surface area. As a result, these materials emerge as promising candidates for high-performance supercapacitor electrodes. The challenges and outlook in NPCs for supercapacitor applications are also presented. Overall, this review will provide valuable insights for researchers in electrochemical energy storage and offers a basis for fabricating highly effective and feasible supercapacitor electrodes.
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Affiliation(s)
- Hafiza Komal Zafar
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Sara Zainab
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Maria Masood
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Manzar Sohail
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Syed Shoaib Ahmad Shah
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, H-12, Islamabad, 44000, Pakistan
| | - Mohammad R Karim
- Center of Excellence for Research in Engineering Materials (CEREM), Deanship of Scientific Research (DSR), College of Engineering, King Saud University, P. O. Box 800, Riyadh, 11421, Saudi Arabia
- K.A. CARE Energy Research and Innovation Center, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Anthony O'Mullane
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
| | - Kostya Ken Ostrikov
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD 4000, Australia
| | - Geoffrey Will
- Energy and Process Engineering Laboratory, School of Mechanical, Medical and Process Engineering, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Md A Wahab
- Energy and Process Engineering Laboratory, School of Mechanical, Medical and Process Engineering, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
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Zhang J, You J, Wei Q, Han JI, Liu Z. Hollow Porous CoO@Reduced Graphene Oxide Self-Supporting Flexible Membrane for High Performance Lithium-Ion Storage. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1986. [PMID: 37446503 DOI: 10.3390/nano13131986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/15/2023]
Abstract
We report an environment-friendly preparation method of rGO-based flexible self-supporting membrane electrodes, combining Co-MOF with graphene oxide and quickly preparing a hollow CoO@rGO flexible self-supporting membrane composite with a porous structure. This unique hollow porous structure can shorten the ion transport path and provide more active sites for lithium ions. The high conductivity of reduced graphene oxide further facilitates the rapid charge transfer and provides sufficient buffer space for the hollow Co-MOF nanocubes during the charging process. We evaluated its electrochemical performance in a coin cell, which showed good rate capability and cycling stability. The CoO@rGO flexible electrode maintains a high specific capacity of 1103 mAh g-1 after 600 cycles at 1.0 A g-1. The high capacity of prepared material is attributed to the synergistic effect of the hollow porous structure and the 3D reduced graphene oxide network. This would be considered a promising new strategy for synthesizing hollow porous-structured rGO-based self-supported flexible electrodes.
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Affiliation(s)
- Junxuan Zhang
- Flexible Display and Printed Electronics Laboratory, Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Jie You
- Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon-Materials, College of Electromechanical Engineering, Qingdao University of Science & Technology, Qingdao 266061, China
| | - Qing Wei
- Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon-Materials, College of Electromechanical Engineering, Qingdao University of Science & Technology, Qingdao 266061, China
| | - Jeong-In Han
- Flexible Display and Printed Electronics Laboratory, Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Zhiming Liu
- Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon-Materials, College of Electromechanical Engineering, Qingdao University of Science & Technology, Qingdao 266061, China
- Qingdao Institute of Bioenergy and Bioprocess Technology, Qingdao Industrial Energy Storage Research Institute, Chinese Academy of Sciences, Qingdao 266101, China
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6
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Zhang C, Zhitomirsky I. Effect of High-Energy Ball Milling, Capping Agents and Alkalizer on Capacitance of Nanostructured FeOOH Anodes. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13101693. [PMID: 37242108 DOI: 10.3390/nano13101693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
This investigation is motivated by interest in nanostructured FeOOH anodes for aqueous asymmetric supercapacitors operating in Na2SO4 electrolyte. The research goal is the fabrication of anodes with high active mass loading of 40 mg cm-2, high capacitance and low resistance. The influence of high-energy ball milling (HEBM), capping agents and alkalizer on the nanostructure and capacitive properties is investigated. HEBM promotes the crystallization of FeOOH, which results in capacitance reduction. Capping agents from the catechol family, such as tetrahydroxy-1,4-benzoquinone (THB) and gallocyanine (GC), facilitate the fabrication of FeOOH nanoparticles, eliminate the formation of micron size particles and allow the fabrication of anodes with enhanced capacitance. The analysis of testing results provided insight into the influence of the chemical structure of the capping agents on nanoparticle synthesis and dispersion. The feasibility of a conceptually new strategy for the synthesis of FeOOH nanoparticles is demonstrated, which is based on the use of polyethylenimine as an organic alkalizer-dispersant. The capacitances of materials prepared using different nanotechnology strategies are compared. The highest capacitance of 6.54 F cm-2 is obtained using GC as a capping agent. The obtained electrodes are promising for applications as anodes for asymmetric supercapacitors.
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Affiliation(s)
- Chengwei Zhang
- Department of Materials Science and Engineering, McMaster University, Hamilton, ON L8S 4L7, Canada
| | - Igor Zhitomirsky
- Department of Materials Science and Engineering, McMaster University, Hamilton, ON L8S 4L7, Canada
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7
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Liao WL, Abdelaal MM, Amirtha RM, Fang CC, Yang CC, Hung TF. In Situ Construction of Nitrogen-Doped and Zinc-Confined Microporous Carbon Enabling Efficient Na +-Storage Abilities. Int J Mol Sci 2023; 24:ijms24108777. [PMID: 37240130 DOI: 10.3390/ijms24108777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 05/08/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
Benefiting from the additional active sites for sodium-ion (Na+) adsorption and porous architecture for electrolyte accessibility, nitrogen-doped porous carbon has been considered the alternative anode material for Na+-storage applications. In this study, nitrogen-doped and zinc-confined microporous carbon (N,Z-MPC) powders are successfully prepared by thermally pyrolyzing the polyhedral ZIF-8 nanoparticles under an argon atmosphere. Following the electrochemical measurements, the N,Z-MPC not only delivers good reversible capacity (423 mAh/g at 0.02 A/g) and comparable rate capability (104 mAh/g at 1.0 A/g) but also achieves a remarkable cyclability (capacity retention: 96.6% after 3000 cycles at 1.0 A/g). Those can be attributed to its intrinsic characteristics: (a) 67% of the disordered structure, (b) 0.38 nm of interplanar distance, (c) a great proportion of sp2-type carbon, (d) abundant microporosity, (e) 16.1% of nitrogen doping, and (f) existence of sodiophilic Zn species, synergistically enhancing the electrochemical performances. Accordingly, the findings observed here support the N,Z-MPC to be a potential anode material enabling exceptional Na+-storage abilities.
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Affiliation(s)
- Wan-Ling Liao
- Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gungjuan Rd., New Taipei City 24301, Taiwan
| | - Mohamed M Abdelaal
- Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gungjuan Rd., New Taipei City 24301, Taiwan
- Tabbin Institute for Metallurgical Studies (TIMS), Tabbin, Helwan 109, Cairo 11421, Egypt
| | - Rene-Mary Amirtha
- Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gungjuan Rd., New Taipei City 24301, Taiwan
| | - Chia-Chen Fang
- Material and Chemical Research Laboratories, Industrial Technology Research Institute, 195, Sec. 4, Chung Hsing Rd., Hsinchu 31040, Taiwan
| | - Chun-Chen Yang
- Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gungjuan Rd., New Taipei City 24301, Taiwan
- Department of Chemical Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., New Taipei City 24301, Taiwan
- Department of Chemical and Materials Engineering, Chang Gung University, 259 Wenhua 1st Rd., Taoyuan 33302, Taiwan
| | - Tai-Feng Hung
- Battery Research Center of Green Energy, Ming Chi University of Technology, 84 Gungjuan Rd., New Taipei City 24301, Taiwan
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Guan Y, Hu K, Su N, Zhang G, Han Y, An M. Review of NiS-Based Electrode Nanomaterials for Supercapacitors. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:979. [PMID: 36985879 PMCID: PMC10056300 DOI: 10.3390/nano13060979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/26/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
As a new type of energy storage device, supercapacitors have the advantages of high-power densities, high safety factors, and low maintenance costs, so they have attracted widespread attention among researchers. However, a major problem with supercapacitors is that their energy densities are not high enough, which limits their application. Therefore, it is crucial to expand the application scenarios of supercapacitors to increase their energy density as much as possible without diminishing their advantages. The classification and working principles of supercapacitors are introduced in this paper. The electrochemical properties of pure NiS materials, NiS composites with carbon materials, NiS composites with sulfide materials, and NiS composites with transition metal oxides for supercapacitors are summarized. This paper may assist in the design of new electrode materials for NiS-based supercapacitors.
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Affiliation(s)
- Yuhao Guan
- College of New Energy, Xi’an Shiyou University, Xi’an 710065, China
| | - Kexie Hu
- College of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Nan Su
- Engineering Science and Technology College of Equipment Engineering, Shanxi Vocational University of Engineering and Technology, Taiyuan 030619, China
| | - Gaohe Zhang
- College of New Energy, Xi’an Shiyou University, Xi’an 710065, China
| | - Yujia Han
- Shanxi Research Institute for Clean Energy, Tsinghua University, Taiyuan 030032, China
| | - Minrong An
- College of New Energy, Xi’an Shiyou University, Xi’an 710065, China
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Luo Y, Xu Y, Li X, Zhang K, Pang Q, Qin A. Boosting the Initial Coulomb Efficiency of Sisal Fiber-Derived Carbon Anode for Sodium Ion Batteries by Microstructure Controlling. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:881. [PMID: 36903760 PMCID: PMC10005348 DOI: 10.3390/nano13050881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 02/19/2023] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
As anode material for sodium ion batteries (SIBs), biomass-derived hard carbon has attracted a great deal of attention from researchers because of its renewable nature and low cost. However, its application is greatly limited due to its low initial Coulomb efficiency (ICE). In this work, we employed a simple two-step method to prepare three different structures of hard carbon materials from sisal fibers and explored the structural effects on the ICE. It was determined that the obtained carbon material, with hollow and tubular structure (TSFC), exhibits the best electrochemical performance, with a high ICE of 76.7%, possessing a large layer spacing, a moderate specific surface area, and a hierarchical porous structure. In order to better understand the sodium storage behavior in this special structural material, exhaustive testing was performed. Combining the experimental and theoretical results, an "adsorption-intercalation" model for the sodium storage mechanism of the TSFC is proposed.
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Affiliation(s)
- Yuan Luo
- Key Lab New Processing Technology for Nonferrous Metal and Materials, Ministry of Education, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China
| | - Yaya Xu
- Key Lab New Processing Technology for Nonferrous Metal and Materials, Ministry of Education, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China
| | - Xuenuan Li
- Key Lab New Processing Technology for Nonferrous Metal and Materials, Ministry of Education, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China
| | - Kaiyou Zhang
- Key Lab New Processing Technology for Nonferrous Metal and Materials, Ministry of Education, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China
| | - Qi Pang
- Guangxi Key Laboratory of Electrochemical Energy Materials, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Aimiao Qin
- Key Lab New Processing Technology for Nonferrous Metal and Materials, Ministry of Education, College of Material Science and Engineering, Guilin University of Technology, Guilin 541004, China
- Guangxi Key Laboratory of Electrochemical Energy Materials, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
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Zhang Y, Liu X, Zhao L, Li Y, Li Z. Simulation and Optimization of CNTs Cold Cathode Emission Grid Structure. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:50. [PMID: 36615960 PMCID: PMC9824370 DOI: 10.3390/nano13010050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Carbon nanotubes (CNTs) show significant advantages in the development of cold cathode X-ray tubes due to their excellent field emission performance; however, there are still some problems, such as short lifetime and the low emission current of large-area CNTs. In this paper, a front-grid carbon nanotube array model was established, and the electric field intensity near the tip of the CNTs' electric field enhancement factor was analytically calculated. A simulation model of a CNT three-dimensional field emission electron gun was established by using computer simulation technology (CST). The effects of grid wire diameter, grid aperture shape, and the distribution of grid projection on the cathode surface on the cathode current, anode current, and electron transmission efficiency were analyzed. The aperture ratio was used to evaluate the grid performance, and the simulation results show that the ideal aperture ratio should be between 65% and 85%. A grid structure combining a coarse grid and a fine grid was designed, which can make the electric field intensity around the grid evenly distributed, and effectively increased the cathode emission current by 24.2% compared with the structure without the fine grid. The effect of grid aperture ratio on the electron transmission efficiency was tested. The simulation results and optimized structure can provide a reference for the grid design of cold cathode emission X-ray tubes.
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Affiliation(s)
- Yang Zhang
- School of Instrument Science and Engineering, Southeast University, Nanjing 210096, China
- Key Laboratory of Micro-Inertial Instruments and Advanced Navigation Technology, Ministry of Education, Nanjing 210096, China
| | - Xinchuan Liu
- CAS Key Laboratory of Nanophotonic Materials and Devices (Preparatory), National Center for Nanoscience and Technology, Beijing 100190, China
| | - Liye Zhao
- School of Instrument Science and Engineering, Southeast University, Nanjing 210096, China
- Key Laboratory of Micro-Inertial Instruments and Advanced Navigation Technology, Ministry of Education, Nanjing 210096, China
| | - Yuanxun Li
- School of Instrument Science and Engineering, Southeast University, Nanjing 210096, China
- Key Laboratory of Micro-Inertial Instruments and Advanced Navigation Technology, Ministry of Education, Nanjing 210096, China
- CAS Key Laboratory of Nanophotonic Materials and Devices (Preparatory), National Center for Nanoscience and Technology, Beijing 100190, China
| | - Zhenjun Li
- CAS Key Laboratory of Nanophotonic Materials and Devices (Preparatory), National Center for Nanoscience and Technology, Beijing 100190, China
- GBA Research Innovation Institute for Nanotechnology, Guangzhou 510700, China
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11
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Chai YD, Pang YL, Lim S, Chong WC, Lai CW, Abdullah AZ. Recent Progress on Tailoring the Biomass-Derived Cellulose Hybrid Composite Photocatalysts. Polymers (Basel) 2022; 14:5244. [PMID: 36501638 PMCID: PMC9736154 DOI: 10.3390/polym14235244] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/17/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022] Open
Abstract
Biomass-derived cellulose hybrid composite materials are promising for application in the field of photocatalysis due to their excellent properties. The excellent properties between biomass-derived cellulose and photocatalyst materials was induced by biocompatibility and high hydrophilicity of the cellulose components. Biomass-derived cellulose exhibited huge amount of electron-rich hydroxyl group which could promote superior interaction with the photocatalyst. Hence, the original sources and types of cellulose, synthesizing methods, and fabrication cellulose composites together with applications are reviewed in this paper. Different types of biomasses such as biochar, activated carbon (AC), cellulose, chitosan, and chitin were discussed. Cellulose is categorized as plant cellulose, bacterial cellulose, algae cellulose, and tunicate cellulose. The extraction and purification steps of cellulose were explained in detail. Next, the common photocatalyst nanomaterials including titanium dioxide (TiO2), zinc oxide (ZnO), graphitic carbon nitride (g-C3N4), and graphene, were introduced based on their distinct structures, advantages, and limitations in water treatment applications. The synthesizing method of TiO2-based photocatalyst includes hydrothermal synthesis, sol-gel synthesis, and chemical vapor deposition synthesis. Different synthesizing methods contribute toward different TiO2 forms in terms of structural phases and surface morphology. The fabrication and performance of cellulose composite catalysts give readers a better understanding of the incorporation of cellulose in the development of sustainable and robust photocatalysts. The modifications including metal doping, non-metal doping, and metal-organic frameworks (MOFs) showed improvements on the degradation performance of cellulose composite catalysts. The information and evidence on the fabrication techniques of biomass-derived cellulose hybrid photocatalyst and its recent application in the field of water treatment were reviewed thoroughly in this review paper.
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Affiliation(s)
- Yi Ding Chai
- Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
| | - Yean Ling Pang
- Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
- Centre for Photonics and Advanced Materials Research, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
| | - Steven Lim
- Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
- Centre for Photonics and Advanced Materials Research, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
| | - Woon Chan Chong
- Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
- Centre for Photonics and Advanced Materials Research, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
| | - Chin Wei Lai
- Nanotechnology & Catalysis Research Centre (NANOCAT), Institute for Advanced Studies, University of Malaya, Kuala Lumpur 50603, Malaysia
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Zhou S. On Capacitance and Energy Storage of Supercapacitor with Dielectric Constant Discontinuity. NANOMATERIALS 2022; 12:nano12152534. [PMID: 35893502 PMCID: PMC9330726 DOI: 10.3390/nano12152534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/15/2022] [Accepted: 07/22/2022] [Indexed: 12/04/2022]
Abstract
The classical density functional theory (CDFT) is applied to investigate influences of electrode dielectric constant on specific differential capacitance Cd and specific energy storage E of a cylindrical electrode pore electrical double layer. Throughout all calculations the electrode dielectric constant varies from 5, corresponding to a dielectric electrode, to εwr= 108 corresponding to a metal electrode. Main findings are summarized as below. (i): By using a far smaller value of the solution relative dielectric constant εr=10, which matches with the reality of extremely narrow tube, one discloses that a rather high saturation voltage is needed to attain the saturation energy storage in the ultra-small pore. (ii): Use of a realistic low εr=10 value brings two obvious effects. First, influence of bulk electrolyte concentration on the Cd is rather small except when the electrode potential is around the zero charge potential; influence on the E curve is almost unobservable. Second, there remain the Cd and E enhancing effects caused by counter-ion valency rise, but strength of the effects reduces greatly with dropping of the εr value; in contrast, the Cd and E reducing effects coming from the counter-ion size enhancing remain significant enough for the low εr value. (iii) A large value of electrode relative dielectric constant εrw always reduces both the capacitance and energy storage; moreover, the effect of the εrw value gets eventually unobservable for small enough pore when the εrw value is beyond the scope corresponding to dielectric electrode. It is analyzed that the above effects take their rise in the repulsion and attraction on the counter-ions and co-ions caused by the electrode bound charges and a strengthened inter-counter-ion electrostatic repulsion originated in the low εr value.
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Affiliation(s)
- Shiqi Zhou
- School of Physics and Electronics, Central South University, Changsha 410083, China
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