JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2022
·Vol. 147
·期 17
·9431-9450
·
IF 4.755
Liu Fu-Ya,Zhou Xue-Ling,Zhao He,Hu Wei-Dong,Xu Jian-Zhong,Jiao Yun-Hong,Qu Hong-Qiang
The synergistic effect and mechanism of the spherical CoSn(OH) 6 (T-CHS) and ammonium polyphosphate (APP) on epoxy resin (EP) were investigated by limiting oxygen index (LOI), vertical combustion test (UL-94), cone calorimeter, tensile machine, thermogravimetric analysis-coupled with a Fourier transform infrared spectrometer (TGA/FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, and Raman spectrometer. The results indicate that when the mass ratio of APP and T-CHS is 5.9:0.1 and 5.5:0.5, respectively, there is a synergistic effect between APP and T-CHS, and the flame retardant EP samples could pass the V-0 level of UL-94 test and their tensile properties have little difference to that of the blank EP. Compared with the blank EP, the total heat release and total smoke production of EP/5.9APP/0.1 T-CHS are decreased by 25% and 26%, respectively. TGA/FTIR results of the EP samples under N 2 atmosphere indicate the NH 3 production of EP/5.9APP/0.1 T-CHS is decreased by 47% and the CO 2 and H 2 O production is increased by 991% and 210%, respectively, when compared with that of the blank EP. APP and T-CHS show a good synergistic effect on promoting the retention of C, Co, Sn, and N elements in the char residues. The char residues of EP/5.9APP/0.1 T-CHS and EP/5.5APP/0.5 T-CHS samples contain Co 3 O 4 , CoO, SnO, SnO 2 , oxides of phosphorus, and Sn element, which form a more compact physical barrier.
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DOI
高影响因子
Energy Storage Materials
·
2017
·
IF 0
Chunlong Dai,Linyu Hu,Min-Qiang Wang,Yuming Chen,Jin Han,Jian Jiang,Yan Zhang,Bolei Shen,Yubin Niu,Shu-Juan Bao,Maowen Xu
Lithium-sulfur (Li-S) batteries are of great importance as promising electrochemical-energy storage systems in view of their overwhelming advantage of energy density . However, their commercial applications are still far away mainly due to fast capacity decay in a high sulfur content caused by low utilization of active material and severe polysulfide dissolution during electrochemical cycling. Here we have designed and prepared uniform α-Ni(OH) 2 hollow spheres constructed from ultrathin nanosheets with the thickness of ~3.5 nm as a hollow sulfur nanosphere host for Li-S batteries. Specifically, the synthesized hierarchical hollow spheres not only manifest the advantages of hollow structure and robust protective shell to encapsulate a very high content of sulfur up to 81 wt%, but also offer sufficient functionalized surfaces to directly bond and entrap polysulfides in hollow sphere. When used as cathode materials for Li-S batteries, the S@Ni(OH) 2 double-shell hollow hybrids exhibit a highly stable cycle life over 1000 cycles at 1 C with a very small capacity decay rate of only ~0.04% per cycle.
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DOI
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 32
·15789-15796
·
IF 9.931
Jiali Sheng,Jiahui Kang,Zhixiong Hu,Yan Yu,Xian-Zhu Fu,Rong Sun,Ching-Ping Wong
Exploring effective electrocatalysts is in urgent demand to boost their large-scale applications for direct ethanol fuel cells. Herein, for the first time, we report nanoparticle-assembled Pd nanocages with efficient catalytic activity towards ethanol electrochemical oxidation. The catalysts are prepared from the second template of a nanosheet surface of amorphous Co(OH)2 octahedral nanocages, which are prepared from the original template of octahedral Cu2O. These Pd octahedral nanocages exhibit a porous rough surface, which consists of smaller Pd nanoparticles, endowing them with highly active surface area and many active sites. For the electrochemical oxidation of ethanol, the Pd nanocages demonstrate superior activity (3765 mA mgPd−1), 4.8 times and 5.9 times those of commercial Pd/C and Pd nanocatalysts, respectively, prepared directly from an octahedral Cu2O original template. Furthermore, the Pd nanocages demonstrate excellent long-term durability.
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DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 21
·7256-7264
·
IF 4.39
Lei Ye,Yeqing Zhang,Limin Wang,LinXiu Zhao,Yaqiong Gong
Due to the slow kinetics of oxygen evolution at the anode, the efficiency of electrocatalytic water decomposition is critically reduced, and its large-scale application is severely restricted. Therefore, it is urgent to develop electrocatalysts with excellent performance and stability to accelerate the oxygen evolution reaction (OER) reaction kinetics. Herein, a self-supporting binder-free electrocatalyst was successfully prepared using in situ grown Cu(OH)2 nanowires on CF as the carrier to grow ZIF-67 via a room temperature immersion method. The combination of Cu(OH)2 nanowires and the unique structure of ZIF-67 forms a three-dimensional nanostructured catalyst, in which the unique structure and the existence of synergy may contribute to a larger electrochemical active surface area, expose more electrochemically active sites, adjust the electronic structure, and accelerate the rate of electron transfer, thus greatly improving the electrocatalytic activity and durability for OER. The as-prepared Cu(OH)2@ZIF-67/CF exhibited excellent OER performance under alkaline conditions and required overpotentials of 205 mV and 276 mV to drive current densities of 10 mA cm−2 and 100 mA cm−2, respectively, with a small Tafel slope of 70.5 mV dec−1 for OER. The stability test of Cu(OH)2@ZIF-67/CF at the current density of 10 mA cm−2 displayed excellent stability for 22 h. This study provides a feasible strategy for the rapid preparation of low-cost and efficient electrocatalysts in alkaline media.
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Yixin Huang,Jing Zou,Jinbin Lin,Haoyu Yang,Mengyun Wang,Jiawen Li,Wei Cao,Baoling Yuan,Jun Ma
The activation of peroxydisulfate (PDS) by organic compounds has attracted increasing attention. However, some inherent drawbacks including quick activator decomposition and poor anti-interference capacity limited the application of organic compound-activated PDS. It was interestingly found that 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) could act as both activator and electron shuttle for PDS activation to enhance diclofenac (DCF) degradation over a pH range of 2.0–11.0. Multiple reactive species of ABTS•+, •OH, and SO4•– were generated in the PDS/ABTS system, while only ABTS•+ and •OH directly contributed to DCF degradation. ABTS•+, generated via the reactions of ABTS with PDS, SO4•–, and •OH, was the dominant reactive species of DCF degradation. No significant decomposition of ABTS was observed in the PDS/ABTS system, and ABTS acted as both activator and electron shuttle. Four possible degradation pathways of DCF were proposed, and the toxicity of DCF decreased after treatment with the PDS/ABTS system. The PDS/ABTS system had good anti-interference capacity to common natural water constituents. Additionally, ABTS was encapsulated into cellulose to obtain ABTS@Ce beads, and the PDS/ABTS@Ce system possessed excellent performance on DCF degradation. This study proposes a new perspective to reconsider the mechanism of activating PDS with organic compounds and highlights the considerable contribution of organic radicals on contaminant removal.
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Min Wang,Jianmin Lu,Lihua Li,Hongji Li,Huifang Liu,Feng Wang
Selective oxidative cleavage of C C bond is pivotal for producing functionalized molecules, useful for organic synthesis and biomass utilization. We herein report the oxidative C(OH) C bond cleavage of secondary alcohols to acids over a copper/1, 10-phenanthroline complex with molecular oxygen as the oxidant. A wide range of secondary alcohols are converted into acids with up to 98% yields. More interestingly, it is effective for breaking up lignin model systems into acids, which is rarely achieved in previous studies. Density functional theory (DFT) calculations indicate a copper-oxo-bridged oxygen dimer is the active species for the C H bond cleavage which is the rate-determining step for C C bond.
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DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2021
·Vol. 45
·期 7
·10895-10911
·
IF 5.164
Xiangrui Zeng,Lulu Wang,Jilin Wang,Zhiqiang Qu
Summary A series of anion exchange membranes (quaternized chitosan/cation metal-organic framework [MIL-X-QCS]) were prepared via purposeful inserting the cationic metal-organic framework as the multifunctional filler into quaternized chitosan (QCS). The successful preparation of the anion exchange membrane was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Scanning electron microscope (SEM). In this research, we converted the charge-balanced MOFs skeleton Cr-MIL-101 into the cationic metal skeleton (Cr-MIL-101) + Cl − by anion stripping, and cooperated with quaternary amine groups to construct a high-speed OH − transmission channel. The introduction of a rigid MOF structure reduces the water uptake and swelling ratio of the composite membrane by 27% and 37%, respectively. At 80°C, the OH − conductivity of the MIL-9-QCS membrane (The composite membrane doped with 9 wt% Cr-MIL-101 crystals) reaches 2.30 × 10 −2 S·cm −1 and the power density reached its maximum (90.2 mW·cm −2 ), and the tensile strength reaches 20.12 MPa, which was higher than 18.7 MPa of Nafion-115 membrane. The spatial network structure of MOFs reduced the methanol permeability of MIL-9-QCS membrane by 24% compared with the original QCS membrane. Furthermore, the MIL-9-QCS composite membrane exhibited excellent alkali stability, where after being soaked in 2 mol L −1 NaOH solution at 60°C for 240 hours, its OH − conductivity still reached 77% of the initial value.
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DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Xiaoqian Chang,Yunpeng Xu,Chun-Liang Hou,Ruihan Wang,Xiaoyang Chang
Upgrading plastic waste into high-value chemicals and achieving recycling is of great significance for sustainable development. Herein, we report a green, mild, solvent- and metal-free catalytic approach that uses hydroxyl-functionalized ionic liquids to induce the cleavage of C-O and O-H bonds in polyethylene glycol (PEG), successfully converting PEG into ethylene glycol diester. Through experiments, NMR analysis and DFT calculations, we find that the anion and cation of [HO-EtMIm][OTf] can respectively act as hydrogen bond acceptors and donors to activate the O-H and C-O bonds in PEG, as well as the C=O double bond in benzoic anhydride. Subsequently, the activated hydroxyl O atom in PEG can attack the carbonyl C atom in benzoic anhydride through nucleophilic action, and the activated O atom in benzoic anhydride can also attack the C atom in PEG through nucleophilic action, thereby undergoing depolymerization and forming new C-O bonds, ultimately generating the target product. This mechanism clearly demonstrates the importance of unique confinement effect of ionic liquids, which is achieved through spatial confinement, electrostatic stabilization, directional activation, and hydrogen bonding synergy, providing corresponding innovative support for future research.
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zhichao Yu,Jingfeng Wang,Wei Cao,Chang Luo,Shanshan Wang,Zhijun Ding,Lei Guo,Zhihong Qiao,Puhong Wang
Metal oxide semiconductor (MOS) gas sensor is an effective tool for NO 2 detection. In this work, a NO 2 sensor based on MXene-OH/ZnMnO was fabricated via a seed layer induced self-assembly method, exhibiting remarkable gas response value(280) to 100 ppm NO 2 under 25℃ and ultraviolet activation. Besides, the prepared sensor presents ultra-fast response and recovery speeds (8/40 s), low detection limit (250 ppb), and high selectivity. The enhanced sensing performance was explained by the first-principles calculations, showing that the increased electrical conductivity, more electron transfer numbers and higher adsorption energy promotes effective transport of charge carriers on the surface of sensing materials and NO 2 gas molecules.
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DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Jie Yu,Zhuoran Hou,Huayu Zhang,Xinsheng Zhou
The fabrication of electrode materials with a high specific capacitance is essential for the development of enhanced performance supercapacitors. A novel binder-free electrode material, composed of MnS/Ni 3 S 2 and Co(OH) 2 , was synthesized on nickel foam by hydrothermal, sulfuration, and electrodeposition techniques. The MnS/Ni 3 S 2 exhibited a unique flower-like structure, resulting in a high specific capacitance of 1780 F g −1 at 1 A/g. By optimizing the synthesis conditions through several characterization and electrochemical tests, the MnS/Ni 3 S 2 @Co(OH) 2 composite was obtained, which displayed an ultrahigh specific capacitance of 2495 F g −1 at 1 A/g and a capacitance retention rate of 86.1% after 5000 cycles at 10 A/g in three-electrode system. The synergistic coupling of MnS/Ni 3 S 2 and Co(OH) 2 , along with the conductive nickel foam substrate, donated towards the excellent electrochemical performance. Furthermore, the MnS/Ni 3 S 2 @Co(OH) 2 //AC asymmetric supercapacitor (ASC) device was constructed with MnS/Ni 3 S 2 @Co(OH) 2 as positive electrode, activated carbon (AC) as negative electrode and 1 M KOH solution as electrolyte, demonstrated a high energy density of 68.6 Wh kg −1 at 750 W kg −1 and excellent cycle stability with 91.2% capacitance retention after 10,000 cycles at 15 A/g. The outstanding electrochemical properties observed in both the pre-electrodeposition and post-electrodeposition samples indicate the effectiveness of reasonable design and construction of composite as a pathway for producing electrode materials with exceptional performance.
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DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2021
·Vol. 50
·期 12
·6772-6783
·
IF 1.938
Hou Xiaoshuo,Yang Ming,Yu Hui,Yang Ying,Li Dan,Dong Xiangting
In this work, a 3D Z-scheme photocatalyst Ag/AgBr/Zn 3 V 2 O 7 (OH) 2 ·2H 2 O (Ag/AgBr/ZVO) was synthesized by a hydrothermal method, and a subsequent surface deposition-optical reduction technique. The prepared flower-like Ag/AgBr/ZVO was characterized by scanning election microscopy (SEM), x-ray powder diffraction (XRD), x-ray photoelectron spectroscopy (XPS), UV-vis spectrophotometry, N 2 adsorption-desorption isotherm based on Brunauer-Emmett-Teller (BET) theory, and electrochemical tests. The photocatalytic degradation performance of the catalyst was investigated by the degradation of methylene blue (MB) dye by visible light irradiation. Compared with bare Zn 3 V 2 O 7 (OH) 2 ·2H 2 O (ZVO) nanoflowers, the photocatalytic effect of the 3D Z-scheme heterojunction Ag/AgBr/ZVO was significantly enhanced. The catalyst of 2h-Ag/AgBr/ZVO exhibited the strongest photocatalytic activity, of which the MB degradation rate is about 98.8% in 100 min, which was about five times that of pure ZVO. The increase in the photodegradation rate is ascribed to the accelerated interface charge-transfer process, the faster photogenerated carrier separation rate and the enhancement of visible light absorption. In view of the trapping of the reaction intermediate and the electron spin resonance (ESR) measurement, we propose a possible Z-scheme photocatalytic mechanism. This improved visible-light response likely originates from a synergistic effect of the different components. This work offered an ideal method for producing stable, efficient, and recyclable photocatalysts suitable for use in the visible light range.
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DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2022
·Vol. 28
·期 68
·e202201985
·
IF 5.02
Hao Zhang,Jixiang Ji,Fa Guo,Zhurui Shen
Graphical The mechanism for alkali-treated photocatalyst in CO 2 photoreduction is studied, especially for demonstrating the role of OH − and metal cations in detail for highly selective production of CO. DFT calculations confirmed that K ions enhance the charge density of nearby atoms to stabilize CO* groups and reduce the reaction energy barrier, inducing the switch of CH 4 to CO. In this work, the modulation of activity and selectivity via photoreduction of carbon dioxide under simulated sunlight was achieved by treating P25 and P25/Pt NPs with KOH. It found that KOH treatment could significantly improve the overall conversion efficiency and switch the selectivity for CO. Photoelectric characterizations and CO 2 -TPD demonstrated that the synergistic effect of K + and OH - accelerated the separation and migration of photogenerated charges, and also improved CO 2 adsorption level. Significantly, the K ions could act as active sites for CO 2 adsorption and further activation. In situ FTIR measurements and DFT calculations confirmed that K + enhanced the charge density of adjacent atoms and stabilize CO* groups, reducing the reaction energy barrier and inducing the switching of original CH 4 to CO, which played a selective regulatory role. This study provides insights into the photocatalytic activity and selectivity of alkali-treated photocatalysts and facilitates the design of efficient and product-specific photocatalysis.
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DOI
高影响因子
危险品化学品经营许可证（带存储）