CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaohui Guan,Mohan Huang,Liu Yang,Guangsheng Wang,Xin Guan
In this paper, two-component nanocages containing CoS x and nickel-cobalt layered double hydroxides (Ni-Co LDH) were facilely synthesized via a multistep transformation approach. The zeolitic imidazolate framework-67 (ZIF-67) nanocrystals were firstly synthesized, and then after partial sulfuration, the CoS x /Ni-Co LDH nanocages were achieved by adding nickel ions for etching and precipitation. The prepared CoS x /Ni-Co LDH nanocages consisted of the hollow rhombic dodecahedral morphology with many nanosheets arrays on the shell. When used as electrode materials for electrochemical capacitors, this CoS x /Ni-Co LDH nanocages deliver a specific capacitance of 1562 F g −1 at a current density of 1 A g −1 . In addition, an asymmetric supercapacitor assembled with CoS x /Ni-Co LDH as cathode and active carbon (AC) as anode shows a high energy density of 35.8 Wh kg −1 at a power density of 800 W kg −1 and has an excellent cycling performance with the retention rate of 94.56% after 10,000 cycles, suggesting their potential application in high-performance electrochemical capacitors. These exceptional electrochemical properties can be attributed to the unique structure and synergistic effects between the metal sulfide and the bimetallic hydroxide, which also indicate the potential application of CoS x /Ni-Co LDH nanocages in high-performance supercapacitors.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 37
·19757-19768
·
IF 14.511
Min Lu,Li An,Jie Yin,Jing Jin,Rui Yang,Bolong Huang,Yang Hu,Yong-Qing Zhao,Pinxian Xi
The electrochemical oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are key electrochemical processes in metal–air batteries and water splitting devices. Aluminium–air batteries, as an important type of metal–air battery, have been considered to be promising power candidates for flexible electronics. Here, we describe electronically engineered amorphous Fe–Co–S sites embedded in Prussian blue analogue (FeCoSx-PBA) hetero-nanoframes. The experimental results and DFT calculations reveal the critical role of the introduced FeCoSx layer to PBA, which enhances the electron transfer and alleviates the overbinding effect of OH* during the OER. The FeCoSx-PBA hybrid system supplies an optimized electronic structure for the alkaline OER, which is also confirmed by the much-lowered overpotential (266 mV at 10 mA cm−2) for the alkaline OER. Furthermore, a flexible Al–air battery based on an FeCoSx-PBA cathode catalyst exhibits a high peak power density (58.3 mW cm−2) and energy density (1483 W h kgAl−1), and outstanding stability for more than 50 h of operation under bending or stretching conditions, demonstrating its potential in the practical application of flexible electronic devices. Our results may provide a new strategy of modulating the electronic structure of air electrode catalysts to efficiently promote the reactivity of alkaline OER and Al–air battery processes.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 19
·4934-4944
·
IF 5.365
Jinghua Liu,Tong Ding,Hao Zhang,Guangcheng Li,Jinmeng Cai,Dongyue Zhao,Ye Tian,Hui Xian,Xueqin Bai,Xingang Li
Herein, we report the high performance of thermally reduced Pt/TiO2(B) catalysts for the catalytic oxidation of CO. Our findings show that through hydrogen spillover from Pt to TiO2, surface-engineered defects of oxygen vacancies are “constructed” on the TiO2 support during the reduction process, thus generating active surface-adsorbed oxygen species. With an increase of the reduction temperature, the TiO2(B) phase gradually transforms to the anatase phase, which takes place from the bulk to the surface of TiO2, and is eventually completed at 700 °C. Compared with the anatase phase, the oxygen vacancies are more easily formed on the TiO2(B) phase, and the latter has much stronger interactions with Pt, as well. As the reduction temperature increases, the metal–support interaction between Pt and TiO2(B) is strengthened. Meanwhile, we simultaneously observe an increase in the dispersion of Pt, the proportion of Pt0 and the adsorbed oxygen species on the surface. Our findings reveal that for thermally reduced Pt/TiO2 catalysts, surface-adsorbed oxygen and Pt0 are active species for the catalytic oxidation of CO. Among the thermally reduced catalysts, H-600 shows the highest catalytic activity because it has the largest amount of active Pt0 sites and surface-adsorbed oxygen species. In addition, it shows high water vapor resistance.
研究领域:
催化化学
·
材料科学
·
环境化学
·
表面科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Wanjun Guo,Zhi-Qiang Wang,Shuang Xiang,Yaxuan Jing,Xiaohui Liu,Yong Guo,Xue-Qing Gong,Yanqin Wang
ABSTRACT Owing to the wide application of primary amines, their selective production via reductive amination has become a crucial research topic. Various metal-supported catalysts (Pt, Ru, Rh, Ir, Co, Ni, etc. ) have been investigated, and metallic species have been recognized as active sites in recent years. Herein, we reveal for the first time that CoO species containing oxygen vacancies within a core-shell-structured Co@CoO catalyst accelerate the ammonolysis of Schiff bases, key intermediates in reductive amination, through NH 3 dissociation to hydride-like NH 2 δ – species, delivering an excellent reductive amination performance. The catalyst is highly stable and was utilized in 10 catalytic cycles for the amination of biomass-derived cyclopentanone (CPO) to cyclopentylamine (CPA) without deactivation. Various computational models in combination with spectroscopic measurements indicated that this catalyst not only drives the dissociation of H 2 to the active H δ – species, but also enables the homolytic cleavage of NH 3 to NH 2 δ – . D 2 isotopic tracing experiments provided further evidence of the direct involvement of hydride-like NH 2 δ – species in Schiff base ammonolysis. Theoretical calculations verified the stable co-adsorption of H δ – and NH 2 δ – , which allows the Schiff base to move freely on the surface of the CoO shell and participate extensively in molecular collisions, resulting in exceptional catalytic activity. This is the first study that demonstrates the potential of metal oxide catalysts for the production of primary amines via reductive amination.
研究领域:
催化
·
化学工程
·
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
Nano Hybrids and Composites
·
2022
·
IF 0
Yue Zhang,Tao Li,Shi Yu Tang,Xin Yue Xie,Ru Zeng Liang,Xiao Xiao Chu
Increasing demands of microwave absorbents require new approaches to enhance the absorbing performance. Metal−organic frameworks (MOFs) could be developed as effective absorbers owing to their outstanding features including intrinsic porosity and high specific area. Herein, novel nanostructured Co-MOF-74 composites have been successfully fabricated via a simple solvothermal method. Excellent absorption performance was achieved for the composite with a minimum reflection loss (RL) of −25.5 dB at 2.5 mm and a broad absorption bandwidth (RL < −10 dB) of 6.7 GHz. Such absorber could be developed as lightweight and high-efficiency absorbing materials, and this work provides inspiration for the design of advanced absorbers with strong dissipation capacity and broad effective bandwidth.
研究领域:
材料科学
·
电磁工程
·
纳米技术
✓ 已验证
DOI
Sustainable Energy & Fuels
·
2021
·Vol. 6
·期 2
·440-448
·
IF 6.367
Xin Liang,Lulu Wang,Yang Wang,Yongchao Liu,Yi Sun,Hongfa Xiang
The functional design of separators has been proved to be one of the most efficient methods to improve the electrochemical performance of lithium–sulfur batteries. In this work, a multifunctional separator with gradual changes to four aspects was constructed by integrating a PVDF-HFP/h-BN membrane with a Co-doped carbon nanofiber. The architecture has four gradations, which offers multifold advantages. First, in terms of density, there is a transition from loose to dense, which results in a higher electrolyte uptake rate, reduces the amount of free electrolyte and further suppresses the shuttle effect. Additionally, in terms of composition, a transition from inorganic to organic is designed, which allows the inorganic and organic components to bind closely and reduces the interfacial resistance. Meanwhile, there is a transition from high electronic conductivity to insulation. The change in electronic conductivity leads to effective conversion of the polysulfide. Finally, in terms of ionic conductivity, there is a transition from low to high, which gives the separator better ability to conduct lithium ions. As a consequence, a battery with the as-constructed multifunctional separator performs with good capacity stability, which demonstrates a new concept for high-performance lithium–sulfur battery design.
研究领域:
材料科学
·
储能技术
·
电池技术
✓ 已验证
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2014
·
IF 1.178
Hu-Yan Li,He Li,Bing-Jie Wang,Qun Gu,Zhi-Qiang Jiang,Xue-Dong Wu
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/chitin nanocrystals (CNC) composite scaffolds were synthesized by the salt leaching and thermally induced phase separation (TIPS) technique. The scaffolds have porous structures with macro-pores (100–300 μm in diameters) and micro-pores (10 μm). The surface characteristics of the scaffolds were characterized by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurement, and the mechanical properties were investigated by a compression test. Human adipose-derived stem cells (hADSCs) were seeded onto the PHBV/CNC scaffolds and in vitro cell culture results showed that the composite scaffolds enhanced the hADSCs adhesion, which implies that the material may have potential application in tissue engineering.
研究领域:
生物材料学
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组织工程学
·
细胞生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 6
·1-11
·
IF 2.8
Zhang Zhengyu,Yang Yujie,Chen Congliang,Chen Dongyang,Zhang Yingming,Meng Yuting,Li Hao
In this study, Ni–Zn–Co ferrite doped with (Al 3+ ) was synthesized by solid-phase synthesis method and its structure was analyzed. By analyzing the X-ray diffraction (XRD) data, it was explained that the Ni 0.45 Zn 0.40 Co 0.15 Fe 2-x Al x O 4 (0 ≤ x ≤ 0.15) ferrite has a single-spinel structure with FD-3 m space group. Additionally, by analyzing the XRD data, it is found that the lattice constant is the largest when Al 3+ is undoped. The range of lattice constant is (8.3751 ~ 8.3900) Å, the range of saturation magnetization ( M s ) is (68.77 ~ 79.39) emu/g, and the range of coercivity ( H c ) is (9.04 ~ 13.10) Oe. When the content of Al 3+ is 0.09, the permeability reaches the highest. In conclusion, the results obtained indicate that this ferrite is suitable for low-frequency electronic devices and also confirm that Fe 3+ was successfully replaced with Al 3+ . This paper provides a new idea for the study of spinel-structured ferrites by doping Al 3+ .
研究领域:
材料科学
·
固体物理
·
磁学
✓ 已验证
DOI
高影响因子
IRANIAN POLYMER JOURNAL
·
2023
·Vol. 32
·期 9
·1189-1197
·
IF 3.1
Luo Yanrong,Lu Chunlan,Zhang Xiaolin,Zhan Shiping
With the widespread use of hydrogels, injectable hydrogels for the human body require higher safety and non-toxicity. The most important is the choice of cross-linking agent to be green. In this study, acylated chitosan macromolecular crosslinkers (MCS) were prepared by maleic acid (MA) and chitosan (CS). Its structure was confirmed by FTIR and 1 H NMR and its degree of acylation was also determined. Then, a series of polymeric network hydrogels were investigated. The cross-linked copolymer poly( N -isopropyacrylamide-maleic acid copolymer)/acylated chitosan P(NIPAM- co -MA)/MCS is a series of thermosensitive hydrogels formed by free radical polymerization of NIPAM and MA with MCS as cross-linking agent. The apparent morphology, thermosensitive transition point, and hydrophilicity were investigated. The results show that the hydrogel has a homogeneous pore structure inside. The optimal low critical solution temperature (LCST) was 36.66 ℃. In addition, with the increase of maleic acid content, the water contact angle of the hydrogel is smaller, that is, the hydrophilic effect is better. The results indicate that the P(NIPAM- co -MA)/MCS hydrogels were synthesized successfully and may be a potential material for biomedical, drug delivery, or absorption application. This study can provide a certain research basis and relevant theoretical basis for clinical practice. Graphical abstract
研究领域:
高分子科学
·
材料科学
·
生物医学工程
·
药物制剂技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Xiaofeng Wang,Chengcheng Zhang,Zuyi Zhang,Yaoming Gai,Qingbo Li
The interface site between metal and support possess unique electronic and morphological structure, providing distinct active centers for favorable reaction in catalytic conversion of biomass derivatives to valuable chemicals. In this study, a series of Cu-Co/CeO x catalysts were prepared for hydrogenolysis of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) via reduction of the corresponding layered double hydroxide precursors. The characterizations indicated the formation of CoCe-Vö interface (Vö denotes oxygen vacancy) and the effect of hydrogen spillover from Cu species to CoCe-Vö interface. Furthermore, the experiments and theoretical calculations verified that CoCe-Vö interface could activate the C O bond. The optimized catalyst showed a DMF yield of > 90% at 180 °C and 1.5 MPa H 2 with no deactivation in the cycling tests. This study reveals the interfacial effects of the nanocatalysts, including the oxygen vacancies and hydrogen spillover, on hydrogenolysis of HMF, which provided a simple and efficient approach for synthesis of high-performance non-noble metal nanocatalysts applied to the hydrogenolysis of various biomass derivatives.
研究领域:
催化化学
·
生物质转化
·
纳米材料科学
✓ 已验证
DOI
高影响因子
CARBON
·
2022
·
IF 11.307
Dangcheng Su,Yuanhua Xiao,Yingliang Liu,Shengang Xu,Shaoming Fang,Shaokui Cao,Xuezhao Wang
2D MXenes (transition metal carbides, Ti 3 C 2 T x ) with large surface area and metallic conductivity are widely used as supporters in catalysts. Unfortunately, the single MXene sheets would deteriorate in the presence of oxygen and water, which is almost the same as the environment of oxygen reduction reaction (ORR). Herein, an “armor” was constructed to encapsulate the oxidizable MXene by a confined in-situ oxidative polymerization strategy, employing the electrostatic interaction between the exfoliated MXene sheets (negatively charged) and oxidant (Fe 3+ , positively charged). The ultra-dispersed binary Fe 3 N and Co sits coupled with the large surface area MXene supporter synergy to endow more exposed active sites, meanwhile, the density functional theory (DFT) studies reveal that a moderate binding strength between the intermediates and the binary active sites was effectively modulated to enhance the ORR performance. The synthesized Fe 3 N/Co–N–C@MXene exhibits an impressive half-wave potential (E 1/2 , 0.871V) and a lower Tafel slope of 52.56 mV dec −1 than that of Pt–C-20% (74.89 mV dec −1 ). The Fe 3 N/Co–N–C@MXene based ZAB exhibits a four times higher peak power density (189.16 mW cm −2 ) than the Pt–C-20% based ZABs and superior cycle stability within 320 h. Furthermore, the assembled flexible ZABs shows high flexibility and stability in different bending scenarios.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源存储与转换
·
功能材料
✓ 已验证
DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2021
·Vol. 83
·期 4
·841-853
·
IF 1.915
Li Dongmei,Li Wenjie,Zhang Quan,Wang Yizhi,Lin Hongyu,Feng Li,Li Shaoxiu,Deng Yue,Xiao Qiurong,Chen Jiongxi,Dong Qi
The promising synergistic electrocatalytic system of phosphate (PO 4 3− ) with the mediator cobalt(II) (for short E-Co(II)-PO 4 3− ) was employed to degrade cationic dye methylene blue (MB). The exploration in the electrocatalytic process revealed that the main intermediate active oxidation products were Co(III), accompanied with hydroxyl radicals and peroxodiphosphates (P 2 O 8 4− ). Their synergistic electrocatalytic degradation rate to MB and total organic carbon (TOC) was up to 100 and 60% in 40 min, respectively, which was 5 times and 2.6 times that in a direct electrocatalytic system, correspondingly. The degradation process of the E-Co(II)-PO 4 3− system on MB started with the bond being broken at the N-C junction of the MB molecule and intermediate active oxidation substances being generated, such as phenothiazine, 2-amino-5-(N-methylformamide) benzene sulfonic acid and N 1 ,N 1 -dimethyl-1,4 diaminobenzene. Then, the intermediates were degraded into aniline, phenol and benzene sulfonic acid, and eventually decomposed into inorganic substances like CO 2 and water. The electrocatalytic degradation mechanism of E-Co(II)-PO 4 3− system on MB was the combination of indirect oxidation of the intermediate oxidants like Co(III), P 2 O 8 4− and the hydroxyl radical with direct electrocatalysis on the platinum titanium electrode, where the electrocatalytic oxidation of Co(III) was dominant. Active Co(III) and peroxodiphosphate generated in a novel electrocatalytic system have synergistic electrocatalytic effect. MB removal rate reached 100% in 40 min in the novel electrocatalytic system with phosphate and the mediator cobalt(II). Co(III) is the dominant active oxidation substance in MB oxidation and mineralization.
研究领域:
环境化学
·
电催化
·
环境污染与控制
·
高级氧化技术
·
环境功能材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）