INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Bingying Gao,Mulenga Kalulu,Olayinka Oderinde,Jing Mei,Lili Ren
Polyvinylpyrrolidone (PVP) modified reduced graphene aerogel (PVP-GA) was prepared through hydrothermal reduction and chemical reduction of graphene oxide (GO) in the presence of PVP. The structure of PVP-GA was characterized using XRD , FTIR , SEM, TEM and BET specific surface area. The results showed that GO was reduced effectively in the presence of PVP and the PVP molecules were absorbed onto the basal plane of reduced graphene oxide (rGO) through non-covalent interactions. The preparation process was carried out in aqueous media at 120 °C for 10 h without using any toxic reducing agent, thereby making it a facile, environmental-friendly and economical approach for the synthesis of a three-dimensional (3D) interconnected graphene macrostructure. The as-prepared monolithic 3D graphene exhibits a loose and high porous structure , which may find potential applications for adsorbent, shock absorber , catalyst carrier and hydrogen storage materials. In addition, it confirmed that simultaneous hydrothermal reduction and chemical reduction routes would be of value for preparing 3D nonporous graphene-based materials via the use of cheap and environmentally-friendly PVP as a reducing agent.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2025
·
IF 11.6
Jing Li,Junhao Liu,Ning Li,Wenfang Zeng,Minghao Chen,Yawei Xu
Graphene, with its excellent thermal conductivity, is ideal for heat dissipation in small electronic devices. In this study, we propose a method that combines magnetic field-induced assembly and catalytic graphitization to enhance the thermal conductivity of graphene films. Fe₃O₄ was loaded onto graphene oxide (GO) to form magnetic graphene oxide (MGO), which was aligned into an ordered structure under the influence of an external magnetic field. Glucose was then added as a carbon source and thermally reduced at 800 °C to fill defects in the MGO films and reduce phonon scattering. Catalytic graphitization using Fe as a catalyst at 1500 °C converted the amorphous carbon to graphitic carbon, further minimizing phonon scattering. Finally, a second graphitization at 1800 °C was performed to repair structural defects, resulting in a thermal conductivity of 1004.4 W m⁻ 1 K⁻ 1 significantly higher than that of the graphene film obtained by reducing GO under the same conditions (420.2 W m⁻ 1 K⁻ 1 ). This energy-efficient approach offers a promising method for preparing high-thermal-conductivity graphene-based materials for future applications.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
高影响因子
SYNTHETIC METALS
·
2018
·
IF 2.526
Sumin Wang,Lu Li,Qiguan Wang,Yaru Fan,Jingwen Shen,Kai Zhang,Lei Yang,Wenzhi Zhang
The surface of graphene (Gr) was covalently attached by an aniline oligomer, from the coupling of graphene oxide with aniline tetramer, followed by reduction process. After linked by tetramer aniline, the graphene materials showed remarkably enhanced electrochemical performances. The conductivity of the graphene was increased from 5.8 S cm −1 to 41.7 S cm ‒1 , under the strong doping effect between Gr and tetramer aniline by means of the π‒π interactions, which was analyzed by FT‒IR, UV–vis and XPS spectra. In addition, the aniline oligomer attached to reduced graphene oxide (AOAG) showed a remarkable energy-storage behavior due to the synergistic effect. The capacitance of AOAGs can be 370 F g −1 , while it is 114 F g −1 and 129 F g −1 for graphene oxide and tetramer aniline respectively. Because the covalent bonding between graphene and aniline oligomer can effectively combine the excellent mechanical strength of graphene and the large faradic pseudocapacitance of aniline oligomer, the AOAGs showed quite high charge-discharge cycle stability besides remarkable capacitance. In addition, the ease of electron motion mediated by the covalent bonding in AOAGs supports the sample significant electrochemical catalysis towards nifedipine. Compared with graphene and tetramer aniline, the oxidative current of nifedipine on AOAG showed five-fold increase.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER INTERNATIONAL
·
2020
·Vol. 69
·期 5
·457-466
·
IF 2.574
Haoyang Sun,Tao Li,Fan Lei,Meng Yang,Dandan Li,Xianhang Huang,Dazhi Sun
Fluorographene (FG) with layer numbers of 3–4 was successfully prepared through facile microwave-assisted liquid phase exfoliation of raw graphite fluoride (GrF). The raw GrF and the as-prepared FG were then directly incorporated into polyamide 66 (PA66) by melt processing without using any surfactants. Microstructural, mechanical and tribological properties of the prepared PA66 composites were investigated. Various characterization results showed that both GrF and FG, as novel solid lubricants, can effectively improve the mechanical and anti-wear performances of the PA66 matrix. It was also found that FG is better at improving mechanical properties and reducing the friction of PA66 than GrF at low concentrations owing to the large surface–volume ratio. The addition of 0.5 wt% FG into PA66 exhibits a ca 13% increase in tensile modulus, ca 5% increase in tensile strength, ca 18% reduction in coefficient of friction (COF) and ca 43% reduction in wear rate. However, at relatively high concentrations, such as 1.0 wt%, GrF shows a better reinforcement effect than FG owing to a uniform dispersion of GrF in the PA66 matrix. The addition of 1.0 wt% GrF into PA66 exhibits a ca 18% increase in tensile modulus, ca 5% increase in tensile strength, ca 37% reduction in COF and ca 46% reduction in wear rate. Wear tests also show that the excellent wear resistance of the PA66 composites is due to the improved mechanical properties and the lubrication of GrF and FG between the worn surfaces. Our current work demonstrates the tremendous potentials of fluorinated carbon materials for enhancing mechanical and anti-wear properties of polymeric materials. © 2020 Society of Chemical Industry
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
SN Applied Sciences
·
2018
·Vol. 1
·期 1
·1-9
·
IF 0
Wei Q.,Wufuer A.,Wang M.,Wang Y.,Dai L.
Three-dimensional graphene (3DG) sponge has attracted increasing attention because it combines the unique properties of cellular materials and the excellent performance of graphene. Preparation of 3DG sponge depends mainly on the self-assembly of graphene oxide sheets. In the case of using uniform large graphene oxide and ultralarge graphene oxide sheets, the nematic liquid crystals (LCs) phases are formed at low concentration. After chemical reduction, the LCs of GO solution are converted to 3DG sponges with a high degree of orientation, offering a new methodology to regulate the controlled large GO sheets. The orientation of GO solution can be inherited by 3DG sponge, making the sponge to have a large-scale ordered network structure. The 3D elastic graphene sponges have low density and good elasticity, promising for the applications in strain sensing, shock damping, and energy cushioning. Our work explores a novel strategy for organizing the ordered alignment of controlled large GO sheets and exploring the relationship between the microstructures and mechanical properties of 3DG sponge.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
ADVANCED MATERIALS
·
2022
·Vol. 34
·期 15
·2107083
·
IF 32.086
Chuanren Ye,Gang Wang,Hong Yuan,Jieyun Li,Kun Ni,Fei Pan,Minghao Guo,Yanhong Wu,Hengxing Ji,Fan Zhang,Bill Qu,Zhiyong Tang,Yanwu Zhu
Graphite oxide and its exfoliated counterpart, graphene oxide, are important precursors for the large-scale production of graphene-based materials and many relevant applications. The current batch-style preparation of graphite oxide suffers from safety concern, long reaction time, and nonuniform product quality, due to the large volume of reactors and slow energy exchange. Reaction in microchannels can largely enhance the oxidization efficiency of graphite due to the enhanced mass transfer and extremely quick energy exchange, by which the controllable oxidization of graphite is achieved in ≈2 min. Comprehensive characterizations show that the graphene oxide obtained through the microfluidic strategy has features like those prepared in laboratory beakers and industrial reactors, yet with the higher oxidization degree and more epoxy groups. More importantly, the microfluidic preparation allows for on-line monitoring of the oxidization by Raman spectroscopy, ready for the dynamical control of reaction condition and product quality. The capability of continuous preparation is also demonstrated by showing the assembly of fibers and reduction of graphene oxide in microfluidic channels, and the applicability of graphene oxide prepared from the microfluidic strategy for thermally and electrically conductive films.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materiomics
·
2020
·
IF 5.797
Shiyu Hou,Shuaijie He,Tianle Zhu,Jihui Li,Liqiang Ma,Hongda Du,Wanci Shen,Feiyu Kang,Zheng-Hong Huang
Exfoliated graphite (EG) is promising oil sorbent as well as an intermediate product for the preparation of flexible graphite films (FGFs). It has been a critical challenge to energy conservation and pollution abatement for the traditional EG production technique. Here, we propose a simple and effective preparation method to acquire EG in which flake graphite is intercalated and exfoliated at room temperature, not involving any pollutant emission. The influence factors in the preparation process were explored, such as the amount of H 2 SO 4 and H 2 O 2 , the temperature for the preparation of room temperature exfoliated graphite (RTEG). In contrast to the EG by high temperature exfoliation (HTEG), RTEG exhibits a homogeneous structure and a significantly increased volume and surface area. Moreover, EG blocks with high oil sorption capacity and excellent reuse performance can be obtained by RTEG method. Especially, FGFs fabricated by RTEG has high flexibility, thermal conductivity and electrical conductivity. It suggests that this environment-friendly technology is suitable for large-scale industrial implementation of graphite-based oil sorbents and flexible materials.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Yangyang Zong,Dayong Gui,Kangmin Niu
There is a lack of systematic research on the use of liquid crystal-modified graphene in the production of thermally conductive composites. In this work, we utilized covalent and non-covalent interactions between 4′-allyloxy-biphenyl-4-ol (AOBPO) and graphene oxide (GO), reduced graphene oxide (rGO), and high-temperature reduced graphene oxide (GNS) to improve the compatibility and dispersion of the fillers with the silicone-cycloaliphatic epoxy resin. The thermal conductivity of GNS-AOBPO composite material significantly increases when a shear force field is applied, even at a lower filler content of 7 wt%, reaching 0.828 W/(m·K), which is 1.8 times higher than that without the field. At 9 wt% filler content, the thermal conductivity further increases to 1.161 W/(m·K), which is 10 times higher than epoxy resin. Concurrently, the electrical resistivity decreased by half. This provides a method for preparing thermal conductive composite materials by inducing the orientation of graphene through the application of a shear force field.
研究领域:
材料科学
·
纳米技术
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2025
·
IF 9.8
Ang Mi,Xinbo Qin,Fei Zhang,Rongping Yun,Youjing Zhao,Min Wang,Xu Xiang
Salt-lake brines have emerged as a promising source of lithium; however, the separation of Li + ions from other coexisting ions remains challenging. To surmount this issue, a three-dimensional wrinkled membrane that was based on a H 1.6 Mn 1.6 O 4 (HMO) ion sieve and comprised graphene oxide (GO) and hydroxylated graphene (GOH) was fabricated in this study. The designed structure provided abundant channels for ion migration. The hydroxyl groups of graphene allowed the membrane to exhibit improved Na + –Li + sieving ability. The lithium adsorption capacity of HMO-GOH/GO (20.6 mg/g) was considerably higher than that of HMO (8.9 mg/g) in a low-concentration lithium solution. The adsorption capacity and separation coefficient of HMO-GOH/GO in a high-sodium brine of Na/Li = 49:1 (48.0 mg/g and 47.1) were higher than those of HMO (21.6 mg/g and 29.3, respectively). The adsorption capacity of HMO-GOH/GO remained at 90.8 % of its initial value after 10 adsorption–desorption cycles, thus demonstrating excellent cyclic stability. HMO/GO-GOH shows higher specific capacitance than HMO based on the cyclic voltammetry results. The density functional theory calculations on adsorption energy of Li + ·4H 2 O and the energy barrier across the GOH pore confirm the Na + /Li + sieving capability. The adsorption mechanism was studied by in situ Raman spectroscopy, verifying the formation of Li O bond during lithium adsorption. Overall, this study provides guidance in the pursuit of a remedy for Na Li separation.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Xin Li,Wendou Feng,Xiangxin Zhang,Songyue Lin,Yuanqiang Chen,Chengwei Chen,Sujing Chen,Wei Wang,Yining Zhang
Monitoring the environmental humidity are of great significance to human comfort and product quality in many fields. However, high performance humidity sensors are difficult to be widely used because of their cost and complex preparation process. It is also highly desirable to develop a facile fabrication method that is capable of producing humidity sensors of customized size, shape, and geometry. Here, using a low power DVD drive, we successfully fabricate a highly sensitivity and low-cost humidity sensor, consisting of laser-scribed graphene (LSG) electrode and graphite oxide (GO) sensing layer. The LSG-GO humidity sensor operates in the relative humidity (RH) range of 19 %–97.4 %, demonstrating high sensitivity (4770.14 pF/% RH), quick response/recovery, and excellent sensing stability. In addition, the possible humidity sensing mechanism is discussed with the help of impedance spectroscopy. These results indicate that the LSG/GO sensor, enabled by the facile fabrication process with low power DVD drives, demonstrates promising potential with broad application prospects.
研究领域:
材料科学
·
传感器技术
·
环境监测
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Jiaming Wu,Zhengmao Ye,Wenxiu Liu,Zhifang Liu,Juan Chen
Ideal electromagnetic absorbing materials with lightweight and high efficiency have broad application outlook in military and civil fields. In this work, a 3D nanostructure material by hybridizing Fe 3 O 4 nanocrystals and reduced graphene oxide (Fe 3 O 4 /rGO) were synthesized through an environmental-friendly one-pot solvothermal method. The effect of GO loading on electromagnetic (EM) wave absorption characteristic of Fe 3 O 4 /rGO was investigated. The introduction of rGO sheets not only prevented Fe 3 O 4 from agglomerating, also improved the absorption performance of Fe 3 O 4 /rGO hybrids. With an appropriate addition, Fe 3 O 4 /rGO obtained a minimum reflection loss (RL) of −22.7 dB and the absorption bandwidth was 3.13 GHz (90% absorption).
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA SCRIPTA
·
2024
·Vol. 99
·期 3
·035924
·
IF 2.6
Ke Zhao,Jianzhao Cao,Ying Qi,Peng Wei,Jian Cheng,Yahong Xie
In our study, we selected three prevalent coal types from Xinjiang: Dahuangshan coal (referred to as Y-coal), Black Mountain coal (B-coal), and Kuche coal (K-coal). Initially, we assessed their morphological differences using electron microscopy. Subsequently, we evaluated the superiority of Y-coal through Thermogravimetric Analysis (TGA). Furthermore, we compared their performances using various electrochemical tests, including the J-V curve, dark current curve, open-circuit voltage curve, and Electrochemical Impedance Spectroscopy (EIS) curve. Ultimately, we investigated the potential of synthesizing graphene from Y-coal and its derivatives. The first step was the preparation of multilayer graphene (MG) by treating Y-coal with acid to obtain demineralized coal, followed by treatment in a tube furnace to obtain ultrafine powdered MG. The second step was then followed by successive oxidation and ultrasonication of the already obtained MG to obtain graphene oxide (GO). Finally, ascorbic acid (VC) was selected to treat GO to prepare an aqueous suspension of reduced graphene oxide (rGO). MG (2θ = 26.2°), GO (2θ = 12.4°) and rGO (2θ = 25.5°) were obtained by XRD analysis. C 1s and O 1S were analyzed by XPS spectra. The functional groups −OH, C=O, and −C=C–, which are unique to graphene and its derivatives, were comparatively analyzed using infrared spectroscopy. The change of π→π* was analyzed by the UV–vis method. The absorbance was further found in combination with PL spectra. Immediately after, the morphology of graphite and its derivatives was analyzed by SEM, HRTEM, the physical properties by contact angle and BET, and finally the content of elements C and O by EDS. The successful demonstration of the superiority of the synthesized MG and its derivatives was achieved.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）