ANALYTICAL CHEMISTRY
·
2012
·
IF 5.856
Qishu Qu,Chenhao Gu,Xiaoya Hu
Graphene oxide (GO) nanosheets were immobilized onto the capillary wall using 3-aminopropyldiethoxymethyl silane as coupling agent. Graphene coated column (G@column) was fabricated by hydrazine reduction of GO modified column. Scanning electron microscopy (SEM) images provided visible evidence of the GO grafted on the capillary wall. Energy dispersive X-ray spectrometry (EDS) indicated the high coverage of the GO on the capillary wall. The G@column exhibited a pH-dependent electroosmotic flow (EOF) from anode to cathode in the pH range of 3–9 while the graphene oxide coated column (GO@column) showed a constant EOF. Both GO@column and G@column were evaluated for open-tubular capillary electrochromatography (OT-CEC). The GO@column was also evaluated for open-tubular capillary liquid chromatography (OT-CLC). Good separation of the tested neutral analytes on the GO@column was achieved on the basis of a typical reversed-phase behavior. On the contrary, G@column showed poor separation performance because of the strong π–π stacking and hydrophobic interactions between graphene and polyaromatic hydrocarbons. The high coverage of GO improved the column phase ratio which makes the GO@column promising for OT-CLC separation. Five of the major known proteins including three glycoisoforms of ovalbumin in chicken egg white were identified in a single run on the GO@column with phosphate buffer (5 mM, pH 7.0) and an applied voltage of 20 kV. The run-to-run, day-to-day, and column-to-column reproducibilities are evaluated by calculating the relative standard deviations (RSDs) of the EOF in OT-CEC and retention time of naphthalene in OT-CLC, respectively. These RSD values were found to be less than 3%.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Huilian Hao,Jianjun Wang,Qiu Lv,Yiding Jiao,Jing Li,Wenyao Li,Isil Akpinar,Wenzhong Shen,Guanjie He
To solve the problems related to the re-stacking of reduced graphene oxides (rGO) and further improve their surface chemical behaviors to satisfy supercapacitor demands. The rGO decorated with graphene quantum dots has been successfully prepared via a facile low-power ultrasonic method. It is demonstrated the graphene quantum dots/reduced graphene oxide electrode has a high specific capacitance of 312 F g −1 , which is nearly three times higher than that of the reduced graphene oxide (132 F g −1 ). The enhanced super-capacitive performances of graphene quantum dots/reduced graphene oxide have been attributed to the introduction of graphene quantum dots, which effectively prevent the aggregation and restacking of reduced graphene oxide sheets, promoting its surface exposed to the electrolyte for sufficient mass transfer. Meanwhile, these features provide more pathways for the transportation of electrons between the interlayer of reduced graphene oxide sheets. Afterward, a detailed energy storage mechanism was analyzed.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2013
·
IF 1.977
Xiyao Teng,Manqing Yan,Hong Bi
The surface characteristics of graphene oxide nanosheets (GO) treated respectively with tartaric acid, malic acid and oxalic acid, have been investigated by mainly using optical spectroscopic methods including Fourier transform infrared spectroscopy (FT-IR), Ultraviolet–visible (UV–Vis) absorption and Raman spectroscopy. Additionally, the electrochemical property of the products has also been studied. The data revealed that oxygen-containing groups such as OH, COOH and C O on the GO surface have been almost removed and thus reduced graphene oxide nanosheets (RGN) were obtained. Interestingly, the number of sp 2 domains of RGN increases as treated by tartaric acid < malic acid < oxalic acid whereas the steric hindrance (SH) decreases and the ionization constant (IC) differs among these three acids. Furthermore, the specific capacitances ( C s ) of GO have been greatly promoted from 2.4 F g −1 to 100.8, 112.4, and 147 F g −1 after treated with tartaric, malic and oxalic acids, respectively. This finding agrees well with the spectra result of the tendency of surface conjugated degree alteration. We claim that the difference in both SH and IC among these acids is the main reason for the diverse surface characteristics as well as the improved C s of the RGN.
研究领域:
材料科学
·
表面化学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Sumin Wang,Kai Zhang,Qiguan Wang,Yaru Fan,Jingwen Shen,Lu Li,Lei Yang,Wenzhi Zhang
In this paper, aqueous solution of reduced graphene oxide has been prepared assisted by the graphene quantum dot , which is then mixed with aqueous polyaniline solution to form water-borne reduced graphene oxide/polyaniline composite powder. The resultant graphene quantum dot-reduced graphene oxide/polyaniline shows a specific morphology of nanosized polyaniline firmly attached on reduced graphene oxide layer, due to the good dispersion of reduced graphene oxide and polyaniline in water. The monodispersion leads to the close contact between reduced graphene oxide sheets and polyaniline particles, significantly depressing the accumulation. It leads to the enhanced conductivity, supercapacitance and cycling stability for graphene quantum dot-reduced graphene oxide/polyaniline, with capacitance as high as 648 F g −1 . After 5000 charge-discharge cycles, the capacitance of as-prepared reduced graphene oxide/polyaniline composite shows just 3.7% decay while it reaches 68% for polyaniline. Furthermore, driven by the strong electrostatic forces between the electropositive polyaniline and the electronegative graphene quantum dot-reduced graphene oxide as well as the π−π interactions, the obtained nanosized graphene quantum dot-reduced graphene oxide/polyaniline films from the controllable layer-by-layer method show the morphology of interconnected-layer networks and exhibit good electrochemical activity on H 2 O 2 in the range of 5.0 × 10 −7 –3.5 × 10 −5 M. The detection limit is as low as 1.1 μM.
研究领域:
材料科学
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电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Biomedical Physics & Engineering Express
·
2019
·Vol. 5
·期 2
·025002
·
IF 0
Orwa Shueibi,Ziyan Zhou,Xianliu Wang,Bingcheng Yi,Xing He,Yanzhong Zhang
Graphene oxide (GO) and reduced graphene oxide (rGO) are two of the most representative graphene derivatives that can be employed to engineer bioactive and/or electroactive scaffolds for neural tissue engineering (NTE). However, a comparison with regard to their chemical structural impact on cytocompatibility has yet to be performed. In this study, GO was prepared using a modified Hummers' method followed by thermal treatment to obtain the rGO. Thereafter, a stable jet electrospinning approach was used to electrospin a viscous mixed solution of polycaprolactone (PCL)/poly(ethylene oxide) (PEO) (mass ratio 4:1) containing a tiny amount of GO and rGO (1% w/w), for the generation of highly-aligned nanoscale fibers of PCL-PEO-GO and PCL-PEO-rGO, respectively. Structural characteristics and physicochemical properties of the GO and/or rGO incorporated PCL-PEO nanofibers were characterized by various analytical techniques including Raman, FTIR, SEM, water drop contact angle, cyclic voltammetry and tensile testing. Finally, biological study in vitro by culturing the fibrous scaffolds with murine Schwann cells for cytocompatibility evaluation demonstrated that comparatively PCL-PEO-GO scaffold could more favorably promote the proliferation of the Schwann cells. However, considering the noted higher electroconductivity, the fibrous PCL-PEO-rGO may be applied to induce stem cell differentiation towards neural lineage. This research could provide a guidance for judicious selection of the GO and rGO incorporated nanofibers to construct electroactive scaffolds for engineering functional neural tissues.
研究领域:
生物医学工程
·
神经组织工程
✓ 已验证
产品关联
DOI
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Jun Wang,Baoliang Chen
The adsorption and coadsorption of naphthalene, 1-naphthol and Cd 2+ onto graphene oxide (GO), chemically reduced graphene (CRG) and annealing reduced graphene (ARG) were compared to determine the unique adsorption properties of graphene nanosheets. The adsorption capability of organic pollutants followed the order CRG > ARG > GO, and all three adsorbents showed stronger adsorption to 1-naphthol than to naphthalene. In addition to a π–π interaction, the strong adsorption of 1-naphthol onto graphene nanosheets was mainly attributed to the n –π electron-donor–acceptor (EDA) interactions between the –OH groups of 1-naphthol and the electron-depleted sites on graphene nanosheets. The adsorption of 1-naphthol on reduced graphene materials increased with increasing pH and reached a maximum around its pKa, supporting the n –π EDA interaction mechanism. GO with more functional groups on the nanosheets over CRG and ARG exhibited a strong affinity with Cd 2+ . The adsorption of Cd 2+ onto GO and CRG facilitated the coadsorption of naphthalene and 1-naphthol via surface-bridging mechanisms, such as cation–π interactions. Notably, though ARG showed no significant Cd 2+ adsorption, the suppressed coadsorption of naphthalene onto ARG may be attributed to the sieving effect by hydrated Cd 2+ binding to the micropore edges on ARG.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2021
·
IF 4.158
Guibin Lou,Lida Shen,Yingjuan Qian,Ya Chen,Huawen Bai,Haixia Cheng,Junwei Xu,Youwen Yang
This work studies the antibacterial and anti-corrosion properties of nickel-graphene oxide (Ni-GO) composite coating and nickel-reduced graphene oxide (Ni-rGO) composite coating deposited by magnetic field assisted scanning jet electrodeposition on manganese steel . Agar plate assessment and cell live/dead staining were used to evaluate the antibacterial property of the two types of composite coatings. The Ni-GO and Ni-rGO composite coatings can effectively improve the antibacterial property of the substrate. The Ni-GO composite coating deposited with graphene oxide (GO) concentration of 0.5 g/L showed the most excellent antibacterial ability, and its antibacterial rate against E. coli and S. aureus within 2 h were 100% and 93%, respectively. Potentiodynamic polarization measurements indicated that the protective efficiency of the two types of composite coatings on the manganese steel reaches 99% after being immersed in 3.5 wt% NaCl solution for 7 days. The combined effect of barrier protection from GO-based materials (GO, rGO) and corrosion products effectively inhibits the corrosion behavior of the two types of composite coatings.
研究领域:
材料科学
·
生物学
·
化学工程
✓ 已验证
DOI
高影响因子
Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-8
·
IF 3.125
Tang Bo,Li Xufei,Huang Weiqiu,Yu Haogang,Ling Xiang
Reduced graphene oxide (RGO) and three-dimensional graphene networks (3DGNs) are adopted to improve the performance of thermal interface materials (TIMs). Therein, the 3DGNs provide a fast transport network for phonons, while the RGO plays as a bridge to enhance the phonon transport ability at the interface between the filler and matrix. The types of surface functional groups of the RGO are found to exert a remarkable influence on the resulting thermal performance; the carboxyl groups are found in the optimal selection to promote the transport process at the interface area because a strong chemical bond will form between the graphene basal plane and epoxy resin (ER) through this kind of group. The resulting thermal conductivity reaches 6.7 Wm −1 K −1 after optimizing the mass fraction and morphology of the filler, which is 3250% higher than that of the pristine ER. Moreover, the mechanical properties of these as-prepared TIMs are also detected, and the specimens by using the RGO(OOH) filler display the better performances.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 31
·15882-15888
·
IF 7.443
Jing Sun,Haifeng Ma,Hong Jiang,Liyun Dang,Qingyi Lu,Feng Gao
We developed a one-step method to obtain a high dispersion of Pt-based alloy nanoparticles on graphene by using both the carrier function and the reducibility of carbon without the addition of any other reducing agent. This method opens up a general and feasible route for the synthesis of different metals, and binary and ternary alloys (such as Pt, Pt–Cu, Pt–Ni, Pt–Ni–Cu, Pt–Co–Cu, Pt–Au–Cu, and so on) on graphene sheets, which would bring potential applications in many fields. Particularly in this study, the obtained PtCu/G composites exhibit superior electrochemical activities and high poison tolerance toward methanol oxidation compared to Pt/graphene and commercial Pt/graphene composites, demonstrating that PtCu/graphene can be used as a promising catalyst for direct methanol fuel cells.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 85
·69854-69860
·
IF 3.84
Suyun Tian,Jing Sun,Siwei Yang,Peng He,Shengju Ding,Guqiao Ding,Xiaoming Xie
Rapid thermal exfoliation/reduction of graphite oxide is a fast and easy method among the oxidation–reduction approaches for graphene synthesis. In this research, we firstly demonstrated that graphene can be obtained with a surface area of 550 to 700 m2 g−1 and a yield of approximately 50% through one-step rapid thermal treatment in air from 450 to 550 °C, without vacuum or protective gas through a self-protection process. Then, we further demonstrated the effective two-step thermal annealing to significantly improve the C/O ratio from ca. 7.3 to 25.9 in air at the relatively low temperature of 600 °C. The smart self-protecting and enhanced-oxygen-removal mechanisms were discussed.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2014
·
IF 8.535
Peng He,Jing Sun,Suyun Tian,Siwei Yang,Shengju Ding,Guqiao Ding,Xiaoming Xie,Mianheng Jiang
Dispersing graphene in various solvents is one of the key technologies toward the practical applications of graphene. Herein, using graphene quantum dots (GQDs) as stabilizer, aqueous dispersions of graphene with good stability were demonstrated by directly dispersing commercialized graphene powder into water. Amazingly, 100 mg of graphene powder could be stabilized by an average of merely 7.8 mg GQDs to form aqueous dispersions with a maximum concentration of up to 0.4 mg/mL and stability at least 3 months. The introduction of a small amount of GQDs also allowed for the fabrication of water-redispersible graphene slurry and powder, which would largely facilitate the transportation and applications of graphene. The mechanism of the GQDs stabilized graphene in water was proposed and experimentally verified through UV–visible spectroscopy and zeta potential measurements. Moreover, flexible graphene papers directly assembled from the water-dispersible graphene exhibited controllable thickness, good conductivity, and acceptable strength. With properties not compromised by GQDs, water-dispersible graphene is expected to be widely applicable in electrical and electrochemical device fields.
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
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2017
·
IF 4.075
Lin Zhang,Hongqiang Li,Xuejun Lai,Xiaofeng Liao,Jing Wang,Xiaojing Su,Heng Liu,Wenjian Wu,Xingrong Zeng
To improve the thermo-oxidative aging resistance of natural rubber , a kind of functionalized graphene (FGE) was prepared by grafting 2- tert -butyl-6-(3-tertbutyl-2-hydroxy-5-methylphenyl) methyl-4-methylp-henyl acrylate (GM) onto graphene oxide (GO) using (3-mercaptopropyl) trimethoxysilane as bridging agent. In comparison to GO, FGE appeared more curled surface and reached the higher water contact angle of 134°. By latex-mixing method, the uniformly dispersed FGE endowed NR vulcanizates with obviously improved thermal stability. Importantly, the NR/FGE nanocomposites exhibitd excellent thermo-oxidative aging resistance, which was attributed to not only the synergistic antioxidative effect of hindered phenol groups and thioether bonds, but also the barrier role of graphene sheets to oxygen. Our findings provide a new strategy to prepare functionalized graphene as effective antioxidant for rubber and other polymer materials.
研究领域:
材料科学
·
高分子化学
✓ 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）