JOURNAL OF CHEMICAL RESEARCH
·
2020
·
IF 0.593
Xiaolin Hu,Lei Liu,Yue Zhang,Aibing Chen
Carbon-based materials with multidimensional structures generally exhibit improved properties compared with single-morphology carbon materials for various applications including catalysis, adsorption, and energy storage. Here, an N-doped mesoporous carbon sphere and sheet composite is prepared by a co-assembly strategy using an ionic liquid ([C18Mim]Br) as the structure-directing agent, ethylenediamine as the catalyst, tetraethyl orthosilicate as the pore-forming agent, and resorcinol formaldehyde resin as the carbon precursor. [C18Mim]Br and ethylenediamine not only induce formation of the unique structure but also lead to in situ nitrogen doping on the N-doped mesoporous carbon skeleton. The obtained N-doped mesoporous carbon shows a unique composite structure of thin sheets embedded with carbon spheres, having high a specific surface area and uniform mesopore distribution. When used as an electrode material, the N-doped mesoporous carbon shows a good specific capacity of 273 F g−1 at a current density of 0.5 A g−1 and a good rate capability (82.1% of the capacitance is retained at a high current density of 10 A g−1). Moreover, the N-doped mesoporous carbon exhibited ideal stability behavior (91.6% capacitive retention after 10,000 cycles), indicating a promising role as an electrode material for excellent performance supercapacitors.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 35
·14970-14978
·
IF 3.288
Jingchuang Zhao,Yingzhen Zhang,Xianyu Kang,Yancai Li
Direct methanol fuel cells (DMFCs) have been extensively studied for developing a new non-precious metal catalyst to replace commercial platinum catalysts, due to their expensive cost and susceptibility to CO poisoning. In this work, nanocomposites of nickel oxide/nickel supported by N-doped carbon (NiO/Ni–N/C) were prepared by using a hydrothermal method and further carbonization at different temperatures. The surface morphology and composition of the NiO/Ni–N/C nanocomposites were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). As observed through electrochemical experiments, the NiO/Ni–N/C nanocomposite modified glassy carbon electrode (NiO/Ni–N/C/GCE) exhibits high electrocatalytic activity for the methanol oxidation reaction (MOR) in alkaline solution. Among the nanocomposites, NiO/Ni–N/C carbonized at 500 °C (NiO/Ni–N/C500) displays the highest mass activity (1043 mA mgNi−1) at 0.73 V (vs. Ag/AgCl), which is much higher than that of Ni(OH)2/N–C and NiO/Ni–N/C carbonized at other temperatures (400, 600, and 700 °C). In addition, the catalytic activity of NiO/Ni–N/C500 is 2.12 times that of the commercial Pt/C. NiO/Ni–N/C500/GCE also possesses fast kinetics, excellent stability and CO tolerance. Therefore, the NiO/Ni–N/C500 nanocomposites have great application potential as MOR catalysts.
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ELECTROCHIMICA ACTA
·
2020
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IF 6.215
Tan Dang,Donghai Wei,Guiqing Zhang,Lei Wang,Qinggang Li,Huaizhi Liu,Zuoying Cao,Guanhua Zhang,Huigao Duan
Rational design of highly active electrode materials made of low-cost and earth-abundant transition metal phosphides is essential to boost the energy density and overall performance of electrochemical capacitors. In this work, homologous 3D NiCoP/CoP hetero-nanosheets network supported on N-doped carbon nanotubes are synthesized through one-step phosphorization of nickel cobalt hydroxide. The synergistic effects between NiCoP and CoP in the heterointerface are studied systematically through tuning the molar ratio of original Ni/Co. As a result, the optimized N-CNTs@NiCoP/CoP (with the Ni/Co ratio of 1:2) reveals a remarkable specific capacity of 152 mAh g −1 at 1 A g −1 and a superior rate capability with a capacity retention of 61% even at 30 A g −1 . A hybrid supercapacitor assembled with N-CNTs@NiCoP/CoP cathode and ZIF-67-derived porous carbon anode exhibits a high energy density of 45.5 Wh kg −1 at power density of 784 W kg −1 and excellent stability of 87% retention after 10,000 cycles at 12 A g −1 . Such excellent electrochemical performance of N-CNTs@NiCoP/CoP is mainly ascribed to the strong synergistic effect between NiCoP and CoP in their heterojunctions, enlarged surface area and active sites due to the 3D nanosheets network and conductive N-CNTs support.
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高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 2
·753-768
·
IF 2.014
Wu Jie,Zhai Wentao,Gao Xue,Liu Bingxin,Zhang Ruling,Yu Yueqin
Well-defined triblock copolymers poly( N -isopropylacrylamide)-b-poly(3-methacryloxypropyltrimethoxysilane)-b-poly( N -isopropylacrylamide) (PNIPAM-b-PMEMO-b-PNIPAM) with varying block ratios were successfully synthesized via reversible addition–fragmentation chain transfer polymerization. The amphiphilic triblock copolymers showed surfactant-like behavior in aqueous solution and could easily self-assemble into dendritic micelles with hydrophobic PMEMO as the core and hydrophilic PNIPAM as the shell when the copolymer concentration exceeded the critical micelle concentration (CMC). Transmittance measurements showed the triblock copolymers were thermosensitive, and it was worth noting that the lower critical solution temperature (LCST) values of copolymers exceeded pure PNIPAM to about 35.3 °C, which was very close to physiological temperature of human body. This was attributed to the effect of Si–O–CH 3 hydrolysis in polymers. The effect of a series of inorganic salts on thermosensitivity of PNIPAM-b-PMEMO-b-PNIPAM was investigated, and our results suggested that the block copolymers maintained good thermosensitivity in all salt solutions. The LCST did not change significantly in different concentrations of NaCl, CaCl 2 and MgCl 2 solutions, which proved the polymer had good salt resistance. Dynamic light scattering experiments showed that the micelles were well dispersed at about 120 nm below LCST with a small polydispersity index. In addition, the drug-loading experiments of micelles showed high drug encapsulation efficiency indicating their potential as drug carriers.
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RSC Advances
·
2020
·Vol. 10
·期 7
·4064-4070
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IF 3.119
Yingna Chang,Qidong Dang,Imran Samo,Yaping Li,Xuejin Li,Guoxin Zhang,Zheng Chang
The removal of heavy metal contaminants has aroused global attention due to water shortage and the lax control on the discharge of heavy metal pollutants. Capacitive deionization (CDI) has emerged as a robust, energy-/cost-efficient technique for water treatment. Herein, we reported the simple synthesis of N, S-co-doped carbon materials (NS-C) derived from PVC plastic wastes as CDI electrode materials for the efficient removal of heavy metal ions (HMIs). The NS-C exhibited a large specific surface area (∼1230 m2 g−1) and contained heavy heteroatom doping (∼4.55 at% N and ∼13.30 at% S). The CDI electrode fabricated using NS-C showed high removal efficiency (94–99%), high capacity (36–62 mg g−1), and good regeneration capability for the adsorption of various kinds of low-concentration heavy metal ions (including Fe2+, Co2+, Ni2+, Cu2+, Pb2+, and Cd2+). Moreover, PVC plastic wastes that are heavily accumulated in the environment and extremely hard to be decomposed and recycled were applied as the carbon source in this study for the fabrication of NS-C, which further rendered the importance of our study in practically treating hazardous waste (HMIs) with waste (PVC plastic wastes) in a clean and efficient way.
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PubMed
高影响因子
Journal of Chemistry
·
2020
·
IF 1.79
Yuchen Ya,Xiaokang Nie,Licheng Peng,Longkai Xiang,Jialong Hu,Wenlong Dong,Huaqiang Chu
Laminar diffusion flame was used to study the effect of ethanol on n-heptane flame in terms of the morphology and microstructure of soot under atomization combustion. For the same carbon mass flux at the outlet of the burner, the ratio of ethanol doping in n-heptane was changed, and the soot was collected from the axial positions of the flame at different heights using the thermophoresis probe method. The results showed that the flame height increased significantly with the increasing ratio of ethanol doping. When the ratio of ethanol and n-heptane (CE/CN) was 1.5, the flame height increased by 10 mm compared with that of pure n-heptane flame. Besides, the temperature in the center of the flame decreased with the increasing ratio of ethanol doping, but the temperature in the low position was higher than that in the pure n-heptane flame, and the temperature in the high position was lower than that in the pure n-heptane flame. However, the flame temperature was the highest when the proportion of ethanol in the mixture was greater than that of n-heptane. The temperature at the flame center decreased with the increasing ratio of ethanol doping, while the temperature at the flame edge increased with the ratio. The primary particle size of soot (soot size hereafter) in all working conditions increased with the increase of flame height, which was in line with the general growth law of soot. Moreover, the soot size at the same height decreased with the increasing ratio of ethanol doping, and this trend was most obvious at the flame height of 20 mm and 30 mm. Compared with pure n-heptane, when CE/CN was 1.5, the soot size at 20 mm and 30 mm decreased by an average of 34.83%, indicating that ethanol could inhibit the surface growth of soot particle. Furthermore, the density of soot particles collected by a single copper net decreased significantly, indicating that ethanol could reduce the production amount of soot.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Xuebin Hou,Huimin Zhou,Min Zhao,Yibing Cai,Qufu Wei
Molybdenum disulfide (MoS2), although it has shown great potential use in electrocatalysis, owns inert basal planes and the low electrical conductivity that limit its effective application. In this work, a MoS2/carbon nanocage hybrid catalyst (MoS2/Co–N–CN2) with a higher density of exposed edge sites and conductivity was developed for efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The hybrid catalyst was successfully prepared via confined growth of MoS2 in the porous carbon matrix derived from the metal organic framework ZIF-67. X-ray photoelectron spectroscopy revealed that the hybrid catalyst contained a significantly higher density of terminal sulfur edges than bulk MoS2. The hybrid catalyst exhibited a high catalytic activity for HER and OER, with low onset overpotentials and small Tafel slopes. This enhanced catalytic performance is a direct result of the increased exposed sulfur edge sites, high surface area, and unique synergic effects between MoS2 nanoplates and Co–N-doped porous carbon matrix. Therefore, the hybrid (MoS2/Co–N–CN2) catalyst serves as a highly promising bifunctional catalyst for HER and OER.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Siyu Zhong,Huaizhi Liu,Donghai Wei,Jin Hu,Hang Zhang,Hongshuai Hou,Meixia Peng,Guanhua Zhang,Huigao Duan
An effective design of carbon materials with appropriate nanoarchitecture and optimized physicochemical property is critically demanded for superb lithium/sodium storage capacities. N-rich (up to 15.7%) hollow carbon nanotubes (NCNT) with long aspect ratio are well developed via a template method by exploring polypyrrole as the high nitrogen-containing carbon precursor. Owing to the hollow structure with large cavity and long aspect ratio, the NCNT exhibits Li + /Na + storage capability with favorable volume buffer and rapid ion and electron transfer at high rate, resulting in long-term cycling and high-rate property. Meanwhile, the high N content creates abundant active sites and extrinsic defects, facilitating the improved specific capacity and rate performance. Impressively, our NCNT-600 electrode displays a favorable reversible capacity of 132 mAh g −1 after 5000 cycles at 4000 mA g −1 for SIBs and 170 mAh g −1 after 2000 cycles at the same current for LIBs. Further quantitative kinetic analysis reveals the dominated capacitive contribution of Li + /Na + storage in NCNT, which is attributed to the porous hollow nanotubes and N-rich carbon with volume strain mitigation and enhanced electronic/ionic transfer capability. Given the cost-effectiveness and material sustainability, our work will shed light on the further design of other carbon-based materials for advanced energy storage devices.
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高影响因子
ACS Omega
·
2020
·
IF 2.87
Yan Ji,Xiaoliang Yang,Zhi Ji,Linhui Zhu,Nana Ma,Dejun Chen,Xianbin Jia,Junming Tang,Yilin Cao
The infrared spectrum (IR) characteristic peaks of amide I, amide II, and amide III bands are marked as amide or peptide characteristic peaks. Through the nuclear magnetic resonance study, N-methylacetamide has been determined to have six fine components, which include protonation, hydration, and hydroxy structures. Then the independent IR spectrum of every component in N-methylacetamide is calculated by using the density functional theory quantum chemistry method, and the contribution of each component to amide I, II, and III bands is analyzed. The results of this research can help to explain the formation of the amide infrared spectrum, which has positive significance in organic chemistry, analytical chemistry, and chemical biology.
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PubMed
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2020
·Vol. 24
·期 2
·104-114
·
IF 2.194
Yang Lijuan,Song Zhaoyang,Yu Yingmin,Zhu Lijun,Xia Daohong
A novel bimetallic bifunctional Pt–NiP/Hβ isomerization catalyst was successfully prepared by introducing a small amount of noble metal Pt into the NiP on the Hβ carrier. The catalyst demonstrated superior catalytic activity to Pt/Hβ and NiP/Hβ catalysts for n -hexane isomerization, due to the good surface property, the synergistic effect of the two metals, the suitable match between acid site and metal site, as well as good reduction stability. The effects of Pt loading and NiP addition amount on the surface property were studied comprehensively through a series of characterization, and the correlation among surface property with catalytic behavior was also analyzed. The results indicated that the Pt (0.1 mol%)–NiP (10 mol%)/Hβ catalyst had good structural characters, surface acid property and an uniform distribution of NiP and Pt active components on surface, which is helpful to obtain a highly efficient catalytic performance. Additionally, the influence of reduction/reaction conditions on the catalytic activity, as well as the catalyst tolerance to water and thiophene sulfur, was investigated furtherly.
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高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Xie He,Yong Han,Xueli Luo,Weixia Yang,Chunhua Li,Wenzhi Tang,Tianli Yue,Zhonghong Li
A ratiometric fluorescence (FL) sensor was fabricated by coordinating 2, 6-pyridinedicarboxylic acid (DPA) sensitized Tb 3+ (Tb-DPA) with NH 2 and COOH on the surface of the N -doped carbon dots ( N -CDs) for detecting Hg 2+ in seafood. The sensor exhibited two FL emissions at 436 nm ( N -CDs) as the response signal and at 543 nm (Tb-DPA) as the reference signal when excited at 290 nm. After adding Hg 2+ , the FL emission at 436 nm was significantly quenched and the FL emission at 543 nm was negligibly changed. The electron transfer (ET) between COO − of N -CDs and Hg 2+ led to the FL quenching of N -CDs. The FL ratio (F 436 /F 543 ) exhibited a good linear relationship in the Hg 2+ concentrations of 1 161.51 μM with a low limit of detection (LOD) of ~37 nM. The sensor presented high selectivity, satisfactory accuracy and precision toward Hg 2+ in seafood with recoveries of 86.45–114.47% and RSDs of 0.20–1.92%.
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PubMed
高影响因子
ChemElectroChem
·
2020
·Vol. 7
·期 3
·745-752
·
IF 4.154
Pan Wang,Ji Qi,Chuang Li,Xiao Chen,Tonghua Wang,Changhai Liang
Graphical One for all : A new strategy is used to grow N-doped carbon nanotubes encapsulating Ni/MoN heterostructures on carbon cloth, exhibiting highly active and stable for overall water splitting, which originates from the high intrinsic activity in the interface of the Ni/MoN heterostructures, the high conductivity and protection of carbon nanotubes, and the three-dimensional structure of the Ni/MoN@NCNT/CC. Herein, we reported a new strategy to grow N-doped carbon nanotubes encapsulating Ni/MoN heterostructures on carbon cloth (Ni/MoN@NCNT/CC). The high intrinsic activity in the interface engineering of the Ni/MoN heterostructures, the high conductivity and protection of NCNT, and the three-dimensional structure of the Ni/MoN@NCNT/CC contribute to its outstanding activity and stability for HER (overpotential of 207 mV at 10 mA cm −2 ) and OER (overpotential of 252 mV at 10 mA cm −2 ). Particularly, for HER, it can maintain a consistent potential at 100 mA cm −2 for 100 h. Besides, for OER the generated surface roughness and larger surface area can enhance OER activity of the catalyst. When used as a bifunctional electrocatalyst for overall water splitting, it can achieve a current density of 10 mA cm −2 at a cell voltage of 1.699 V with excellent durability. This work provides a new strategy to fabricate three-dimensional heterostructured water-splitting electrocatalysts with large surface area.
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