COMPOSITES SCIENCE AND TECHNOLOGY
·
2022
·
IF 9.879
Dongwei Xu,Yumei Ren,Xiaoqin Guo,Desheng Feng,Run Yang,Biao Zhao,Rui Zhang
Multiscale and multicomponent design has been recognized as one of the most effective strategies to improve absorption performance of microwave absorption materials . Herein, the magnetic functional composites aerogels containing core-shell CoO@Co nanoparticles , porous graphene nanosheets (PGN) and carbon nanotubes (CNTs) were successfully fabricated by combining solvothermal method and subsequently calcination processes. The results demonstrated that the calcination temperatures determined the chemical composition (CoO, α-Co, β-Co and CNTs) and complex structure (core-shell and porous characteristics) of the resultant composites aerogels, which affected the magnetic properties and electromagnetic parameters . Interestingly, at the calcination temperature of 650 °C, CNTs were uniformly grown on the surface of porous graphene nanosheets under self-generated cobalt metal catalyst . As expected, the paraffin-based composites aerogels of S650 samples with 15 wt% filling contents presented outstanding microwave absorption performance (MAP) in view of both minimum reflection loss ( RLmin , −63.39 dB, d = 3.4 mm) and the effective absorption bandwidth ( EAB , RL values below −10 dB, 6.5 GHz, d = 2.4 mm). Considering these excellent properties in mind, the composites aerogels with unique complex structures hold great promise as synergistic microwave absorbers for electromagnetic pollution .
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DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 27
·14438-14444
·
IF 7.443
Wen-Ze Qiu,Hao-Cheng Yang,Ling-Shu Wan,Zhi-Kang Xu
Mussel-inspired chemistry has been broadly exploited for multifunctional coatings in the surface modification of applied materials. Polyphenols are ubiquitous in plant tissues and far less expensive than polydopamine for mussel-inspired chemistry. Herein, we report a facile and effective method to modify porous membranes via the co-deposition of catechol (CCh) and polyethyleneimine (PEI). The membrane structures and properties were investigated by ATR/FTIR, XPS, FESEM, zeta potential, water contact angle and pure water flux measurements. The results reveal that the membranes deposited with a CCh–PEI mass ratio of 1 : 0.25 show excellent hydrophilicity, ultrahigh water permeation flux and distinguished surface charges. These membranes were used to decolorize anionic dye solutions during filtration with superior removal efficiencies of over 99%. Moreover, they have good reusability over repeated operations with a simple regeneration process.
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高影响因子
ORGANOMETALLICS
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2022
·
IF 3.837
Tongshun An,Chenwei Liu,Yanzhao Yin,Xiao-Feng Wu,Zhiping Yin
A general palladium and silver co-catalyzed denitrogenative carbonylation of benzotriazoles for the synthesis of benzoxazin-4-ones has been developed. Employing benzotriazoles as easily accessible substrates and Cr(CO)6 as bench-stable solid carbonyl sources, various benzoxazin-4-ones were synthesized through a ring-opening/denitrogenative/carbonylation cascade processes in moderate to good yields. Notably, this protocol avoids the use of toxic CO gas and special equipment and can also be applied to the late-stage functionalization of substrates derived from the uricosuric agent probenecid.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Shaobo Shi,Yu Yang,Jianping Xu,Lan Li,Xiaosong Zhang,Guo-Hua Hu,Zhi-Min Dang
Zn 1− x Co x O (0 ⩽ x ⩽ 0.06) nanorods were fabricated by hydrothermal method. The effect of Co doping on the morphology, crystalline structure, optical and magnetic properties of the samples was investigated. The length of obtained ZnO nanorods increases with the increasing Co concentration. Based on the results of X-ray diffraction and Raman spectra, it is confirmed that a small amount of Co ions are incorporated into ZnO lattice. The segregated phase of Co 3 O 4 was detected at x > 0.01. The absorption and photoluminescence spectra reveal the d–d electronic transitions of tetrahedrally coordinated Co 2+ in ZnO host. Co doping induces fluorescent quenching of the visible emission bands related to surface states and defect states in the Co-doped ZnO nanorods. Weak room temperature ferromagnetism was observed in the samples with x = 0.01 and then paramagnetic characteristics of the samples with x > 0.01.
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高影响因子
MATERIALS LETTERS
·
2019
·
IF 3.019
Qilei Wu,Jun Wang,Huihui Jin,Tingyu Yan,Guoqiang Yi,Xiaogang Su,Wei Dai,Xiang Wang
Nanoporous carbon (NPC) composites embedded with magnetic nanoparticles have been widely studied for applications in microwave absorption. Herein, highly porous rambutan-like carbon composites decorated with controllable carbon nanotubes (CNTs) and Co nanoparticles were synthesized through a thermal decomposition of Co-doped zeolitic imidazolate frameworks-8 (ZIF-8) under different temperatures. The MOF-derived carbon nanocomposites with the cobalt content accounting for 30% of the total mass of cobalt and zinc, carbonized at 700 °C, exhibited excellent microwave absorption property of −30.2 dB. Characterizations exhibit that the in-situ generated Co nanoparticles are uniformly embedded into NPC matrix, which are surrounded by highly graphitized CNTs. The research presents a facile and promising route for rapid mass production of metal-doped NPC/CNTs composites for high-efficiency microwave absorption.
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高影响因子
Frontiers of Environmental Science & Engineering
·
2021
·Vol. 15
·期 6
·1-12
·
IF 4.357
Meng Fanling,Xia Yunxue,Zhang Jianshuai,Qiu Dong,Chu Yaozhu,Tang Yuanyuan
Chromium slag usually contains various heavy metals, making its safe treatment difficult. Glass-ceramic sintering has been applied to resolve this issue and emerged as an effective method for metal immobilization by incorporating heavy metals into stable crystal structures. Currently, there is limited knowledge about the reaction pathways adopted by multiple heavy metals and the co-stabilization functions of the crystal structure. To study the Cu/Cr co-stabilization mechanisms during thermal treatment, a simulated system was prepared using a mixture with a molar ratio of Al 2 O 3 :Fe 2 O 3 :Cr 2 O 3 : CuO = 1:1:1:3. The samples were sintered at temperatures 600–1300°C followed by intensive analysis of phase constitutions and microstructure development. A spinel phase (CuFe x Al y Cr 2− x − y O 4 ) started to generate at 700°C and the incorporation of Cu/Cr into the spinel largely complete at 900°C, although the spinel peak intensity continued increasing slightly at temperatures above 900°C. Fe 2 O 3 /Cr 2 O 3 was more easily incorporated into the spinel at lower temperatures, while more Al 2 O 3 was gradually incorporated into the spinel at higher temperatures. Additionally, sintered sample microstructures became more condensed and smoother with increased sintering temperature. Cu / Cr leachability substantially decreased after Cu/Cr incorporation into the spinel phase at elevated temperatures. At 600°C, the leached ratios for Cu and Cr were 6.28% and 0.65%, respectively. When sintering temperature was increased to 1300°C, the leached ratios for all metal components in the system were below 0.2%. This study proposes a sustainable method for managing Cu/Cr co-exist slag at reasonable temperatures.
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高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Shuang Yao,Tong Zhang,Xiaoyu Tang,Delong Li,Weihao Zhang,Dong Lin,Ruiying Li,Hao Yan,Yibin Liu,Xiang Feng,Xiaobo Chen,Xin Zhou,Chaohe Yang
As a potential alternative for fossil feedstocks, renewable natural oils are highly desirable for producing fuels or high added-value chemicals. Herein, catalytic transfer hydrogenation of methyl stearate to octadecanol using methanol and water as hydrogen donors was investigated over Co/hydroxyapatite (HAP) catalysts synthesized by distinct methods. Multicharacterizations revealed that the strong interaction between Co and the HAP support of the Co/HAP catalysts could enhance the electron transferability, resulting in the excellent methyl stearate conversion (94.8%) and octadecanol selectivity (67.7%) at 290 °C in 5 h. The characterizations and density functional theory (DFT) calculations confirmed that the combined Co0/Coδ+ active sites could synergistically boost the generation of H2 and the hydrogenation of methyl stearate in the methanol/water system. In addition, the effects of various reaction conditions (e.g., the amount of methanol, reaction temperature, reaction time, and catalyst loading) were investigated in detail to understand the plausible reaction pathways. The results may have guiding significance on designing catalysts for efficient conversion of fatty acid methyl esters.
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高影响因子
EES Catalysis
·
2025
·
IF 8.1
Jie Yang,Lifang Chen,Xuya Zhu,Wenwen Shi,Mengxue Huang,Chang Liu,Ruimin Ding,Lin Gan,Xi Yin
H2O2 -related electrochemical reactions, including two-electron oxygen reduction reaction (2e-ORR), H2O2 oxidation reaction (HPOR), and H2O2 reduction reaction (HPRR), have received significant attention for the electrosynthesis H2O2 and energy storage. Understanding the complex structure-activity relationships among 2e-ORR/ HPOR/HPRR and their connections is crucial for further developing highly efficient catalysts and working systems. Herein, we unveil these intricacies by employing model Co-N-C catalysts with well-defined active site configuration (Co-N4-pyrrolic and Co-N4- pyridinic ) in a combined experimental and computational approach. We report the higher 2e-ORR/HPOR but lower HPRR activity of CoN4-pyrrolic site than the CoN4-pyridinic site based on their reaction free energy landscapes remodeled considering the chemisorption steps of O2 and H2O2 . The results reveal that the binding free energy of *OOH (ΔG*OOH ) can only be utilized as a reliable descriptor for 2e-ORR/HPOR activity, but not indicative of HPRR activity, regardless of the scaling relationship of the common reaction intermediates ( *OOH or *OH). The HPRR activity of CoN 4 sites strongly depends on the H2O2 adsorption strength and configuration. These findings provide valuable insights into the design of catalysts for H2O2 -related electrochemical energy conversion and storage systems.
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产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2025
·
IF 4.1
Yongheng Xiong,Yang Yu,Huangang Shi,Jifa Qu,Wenyi Tan
Single atom Fe sites, doped in CN materials, exhibit outstanding electrochemical activity for CO2-to-CO conversion. The pyrolysis of ZIF8 is a controllable method for fabricating isolated single atom metal sites. In this study, we propose a new strategy to increase the ratio of Fe in ZIF8 precursors by synergistically replacing Zn2+ with Bi3+ and Fe3+. After precursor pyrolysis, the obtained Bi/Fe–N–C catalysts, consisting of Bi sites and pyrrole-type Fe–Nx sites, serve as efficient electrocatalysts for the CO2RR. The results show that the optimized catalyst loaded with 94.8 mg per kgCat Fe exhibits a high FECO of >90.1% over a wide potential range of −0.4 to −0.7 VRHE (98.2% at −0.5 VRHE). Insights into the electrochemical reaction mechanism show that this successful design of Bi/Fe–N–C catalysts can provide a stable catalytic site to form *COOH, thus achieving energy-efficient electrochemical CO2 reduction to CO.
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产品关联
DOI
高影响因子
Nano-Micro Letters
·
2019
·Vol. 11
·期 1
·1-11
·
IF 9.043
Tang Zeming,Zhao Yingxuan,Lai Qingxue,Zhong Jia,Liang Yanyu
Abstract A novel nonprecious metal material consisting of Co-embedded porous interconnected multichannel carbon nanofibers (Co/IMCCNFs) was rationally designed for oxygen reduction reaction (ORR) electrocatalysis. In the synthesis, ZnCo 2 O 4 was employed to form interconnected mesoporous channels and provide highly active Co 3 O 4 /Co core–shell nanoparticle-based sites for the ORR. The IMC structure with a large synergistic effect of the N and Co active sites provided fast ORR electrocatalysis kinetics. The Co/IMCCNFs exhibited a high half-wave potential of 0.82 V (vs. reversible hydrogen electrode) and excellent stability with a current retention up to 88% after 12,000 cycles in a current–time test, which is only 55% for 30 wt% Pt/C.
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高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2016
·Vol. 91
·期 11
·2842-2851
·
IF 2.738
Dingsheng Chen,Chaoping Cen,Jinxi Feng,Chunyang Yao,Waiqing Li,Shuanghong Tian,Ya Xiong
BACKGROUND It is of great interest to use pillared clay (PILC) as a cheap support for a selective catalytic reduction (SCR) catalyst. Al-Cr pillared clay (AlCr-PILC) has high thermal stability due to the introduction of polycations of Al. As a support, AlCr-PILC may show a co-catalytic effect in SCR processes because chromium oxide itself is an active SCR catalyst. The aim of this work is to investigate the potential of AlCr-PILC as a new low temperature SCR catalyst support. RESULTS A series of AlCr-PILC with Al:Cr molar ratio varying from 0:4 to 4:0 were successfully synthesized to support manganese and cerium active phase. MnCe/AlCr(2:2)-PILC exhibited the highest NO x conversion close to 100% at 200–300 °C, and more than 90% N 2 selectively over a wide temperature window of 140–300 °C. The catalytic activity of MnCe/AlCr-PILC in terms of both NO x conversion and N 2 selectivity is much higher than those of MnCe/Al-PILC, MnCe/Cr-PILC, AlCr-PILC, and the simple mixed MnCeAlCr, indicating the co-catalytic effect of AlCr-PILC support. CONCLUSION AlCr-PILC is a very promising low-temperature SCR catalyst support. The XRD, XPS, and H 2 -TPR measurements prove that the co-catalytic effect of AlCr-PILC occurred via the strong interaction between MnCe and the AlCr-PILC support. © 2016 Society of Chemical Industry
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高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Chunhao Wang,Xiang Xu,Yang Guo,Fan Zhou,Hongyu Chen,Haoyang Li,Zheng Zeng,Liqing Li
The cobalt carbide (Co2C) innovatively prepared from Co–Mn layered double hydroxide (CoMn LDH) has been investigated and evaluated toward its alternative synthesis conditions and different catalytic performances. Along with various characterization techniques, the preparation basically contains four steps (synthesis of CoMn LDH, calcination, reduction, and crystallization) that transform CoMn LDH to CoMn spinel and then to Co2C. Catalyst evaluation toward toluene pyrolysis was conducted. The sample with Co2C exhibited almost 100% conversion rate of toluene, where the resulting hydrogen yield (∼1.8%) is 6 times more than that of the blank test by using silica sand (∼0.3%), realizing the full transfer of hydrogen element from toluene to hydrogen molecule. Furthermore, based on the textural analysis and density functional dispersion correction calculation, which theoretically explained the easy accessibility of toluene to the crystal surface of Co2C(001) with a relatively high adsorption energy (about −280 kJ mol–1), it suggested that Co2C may expand more extensive applications in the field of catalysis.
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高影响因子
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