ACS Omega
·
2020
·
IF 2.87
Ping Fan,Jiahao Tang,Shunxin Jia,Pengbo Liu,Jintao Yang,Feng Chen,Zhengdong Fei,Mingqiang Zhong
Two nanocomposites with a hierarchical structure (GO@CuSilicate@Fe3O4 and GO@Fe3O4@CuSilicate) were fabricated in this paper. These as-synthesized nanocomposites were analyzed for their structural, compositional, and morphological features by X-ray diffraction, scanning electron microscopy (SEM), Raman spectroscopy, and Brunauer–Emmett–Teller methods. SEM images showed that both nanocomposites had a core–shell structure, and their shells were composed of CuSilicate nanoneedle arrays. Further, their total electromagnetic shielding efficiency was measured and compared in a wide frequency range of 8–12 GHz (X-band). Because of the “antenna” role of CuSilicate nanoneedle arrays and the polarization at the interface between graphene oxide (GO) and Fe3O4, GO@Fe3O4@CuSilicate showed higher electromagnetic shielding performance than that of GO@CuSilicate@Fe3O4. With 1 mm thickness, GO@Fe3O4@CuSilicate showed a high electromagnetic shielding efficiency (over 40 dB) in the whole X-band (8.2–12.4 GHz) and reached a maximum value (41.8 dB) at 8.2 GHz. Its total electromagnetic shielding efficiency was mainly contributed by absorption rather than reflection. This study provided an idea for the structural design of high-performance electromagnetic shielding materials in the GHz frequency range (X band).
研究领域:
材料科学
·
电磁学
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高影响因子
Materials Advances
·
2023
·Vol. 5
·期 3
·1234-1239
·
IF 5
Yi Lv,Jing Yang,Haibo Li,Wei Liu,Gangfeng Ouyang
In this paper, the structures and optical properties of copper(I) halide mononuclear hybrids have been studied. Three pairs of compounds with different organic ligands have been synthesized by a precursor approach, exhibiting significantly enhanced stability compared to typical copper halide monomers by the formation of stronger Cu–P bonds, proving that copper halide monomer-type hybrid compounds have the potential to be developed into high-performance light-emitting materials.
研究领域:
材料化学
·
光学材料
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Hui Xu,Yuhang Zhong,Dingke Wang,Ran Sun,Yujie Tan,Xingang Liu,Jianyuan Hou,Yuan Yuan,Ximan Dong,Renxi Zhang
Cu/Z-700 enables plasma-driven H₂ evolution from simulated seawater vapor. • Dynamic Cu redox cycling acts as an electron relay during plasma catalysis. • Cu clusters, Cu N sites, and pyridinic N perform differentiated functions. • An H₂ rate of 1.33 mL min −1 is achieved with >95% activity after five cycles. How different active sites cooperate under non-thermal plasma (NTP) conditions is still poorly understood. Here, Cu-doped ZIF-8-derived carbon carbonized at 700 °C (Cu/Z-700) is shown to host three distinct active centers: metallic Cu clusters, Cu–N coordinated (Cu–NC) moieties and pyridinic N (Py-N) sites. Cu K-edge X-ray absorption spectroscopy reveals that ~80% of Cu exists as metallic clusters and ~ 20% as isolated Cu δ+ –Nₓ sites. Density functional theory (DFT) calculations suggest a functional division among the three sites: Cu clusters show the strongest Cu–OH binding and the most favorable reaction free energies, Cu–NC sites favor intermediate conversion and product desorption, and Py-N sites promote water adsorption. In a dielectric barrier discharge (DBD), Cu/Z-700 delivers a H₂ production rate of 1.33 mL min −1 from water vapor generated from simulated seawater at a residence time of 3 s, an 11-fold enhancement over plasma alone, with 93.6% activity retention over 20 cycles. Gas-phase product analysis shows that more than 97% of the H₂ originates from water splitting. The results clarify the nature of the active sites in Cu/ZIF-8-derived carbon and their contribution to plasma-catalytic water splitting. Download: Download high-res image (169KB) Download: Download full-size image
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ACS Catalysis
·
2026
·
IF 13.6
Shi Zhanghan,Duan Fangyu,Liu Yafei,Zhang Xianwang,Song Guoquan,Yang Xiaomeng,Ma Qianli,Zhang Zongwu,Wu Dan,Xu Chunbao,Zhang Yongsheng
Cascade catalytic upgrading of biomass-derived furanic compounds to high-value cyclopentanone (CPO) and cyclopentanol (CPL) over metal–acid bifunctional catalysts has attracted considerable attention in sustainable chemistry. However, conventional bifunctional catalysts exhibit insufficient synergistic effects, primarily due to the lack of flexibility in tuning the ratio of acidic to hydrogenative active sites. Herein, we demonstrate that halogen (Br and Cl) modification of supported Cu catalysts significantly enhances both activity and selectivity in the aqueous-phase hydrogenative rearrangement of furfuryl alcohol (FOL), achieving a CPO yield of 94.4% and a CPL yield of 94.6%, respectively. Extensive characterizations reveal that the electronegative Br and Cl adatoms effectively modulate the electronic state of Cu nanoparticles, facilitating the formation of Lewis acidic Cu + sites on the catalyst surface. Mechanistic investigations disclose that Cu + sites mediate the rearrangement of FOL to 4-hydroxy-2-cyclopentenone (4-HCP), while adjacent Cu 0 sites catalyze the hydrogenation of 4-HCP to CPO, followed by its subsequent hydrogenation to CPL. Different binding strengths between Cu and halogens (I > Br > Cl) allow the regulation of the Cu + /Cu 0 ratio on the Cu surface, which in turn provides an effective way to control the reaction pathway. The developed halogen modification strategy not only offers great potential for the upgrading of biomass-derived furanics to cyclopentane derivatives but also presents a versatile strategy for regulating the surface Lewis acidity of metal catalysts, which is crucial for metal–acid bifunctional catalysis.
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高影响因子
Catalysis Science & Technology
·
2015
·Vol. 6
·期 9
·3027-3037
·
IF 5.426
Yanan Liu,Yufei He,Daran Zhou,Junting Feng,Dianqing Li
Aiming at the preparation of catalysts with well-controlled structures, bimetallic PdCu catalysts containing only small amounts of Pd were prepared by two different methods for partial hydrogenation of acetylene. The highly dispersed and stable PdCu catalyst with the Pd : Cu atomic ratio of 1 : 40 was obtained from a Pd(OH)2/CuMgAl hydrotalcite (HT) precursor by a modified co-precipitation method. The obtained PdCu catalyst possessed uniform PdCu nanoalloys with an average size of 1.8 ± 0.3 nm. As a comparison, the impregnation method was also employed to prepare bimetallic PdCu catalysts and it was confirmed that the Pd-rich(core)–Cu-rich(shell) structure was dominant. Under identical reaction conditions, approximately 100% conversion and 82% selectivity at 100 °C were achieved using the PdCu nanoalloy catalyst which were 23% and 12% higher than those of the Pd-rich(core)–Cu-rich(shell) catalyst. The preferable activity was ascribed to the homogeneous nanoalloy structure and small size effect. The enhanced selectivity was attributed to the strong synergistic effect of PdCu. More significantly, this superior catalytic performance can be retained after 48 h of continuous reaction due to the excellent resistibility against carbon deposition and the confinement effect.
研究领域:
催化化学
·
材料科学
·
有机合成
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DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·800
·
IF 3.9
Zhong Xie,Jinpei Hei,Lei Cheng,Jing Li,Xiaojie Yin,Sugang Meng
CO2hydrogenation to methanol was conducted using a set of activated carbon-supported Cu/ZnO/Al2O3catalysts (CCZA) prepared by an incipient wetness impregnation approach. The effect of the Cu/Al ratio on the physicochemical properties of the catalysts, as well as their catalytic performance, were investigated. As Cu/Al ratio increased, the metallic Cu surface area displayed a reducing trend from 6.88 to 4.18 m2∙gcat−1, while the CO2adsorption capacity exhibited an increasing trend. Meanwhile, aluminum content will have an important effect on the catalysts’ reducibility and, thus, on their catalytic performance. The CCZA-2.7-de catalyst demonstrated the highest selectivity to methanol at 83.75% due to the excellent distribution and synergistic effect of copper and zinc. Although the CO2conversion of CCZA-2.2-de and CCZA-3.5-de exceeded 10%, the CH3OH selectivity was less than 60%, which may be attributed to the larger particle sizes of ZnO and poor interactions in Cu–Zn. The present study offers a novel approach to increase the number of active sites, optimize the activated carbon-aided Cu/ZnO/Al2O3catalyst’s composition, and finally elucidate the mechanism for CO2hydrogenation to methanol.Keywords:CO2hydrogenation;CuO/ZnO/Al2O3catalyst;methanol synthesis;carbon-supported catalyst;thermocatalysis
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高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Zibin Pan,Zhengxian Chen,Gary Owens,Zuliang Chen
Biosynthesis strategies are promising methods for the sustainable preparation of nanoparticles because they are less toxic to living organisms and the environment. However, there are still several knowledge gaps concerning the exact mechanisms involved in the biosynthesis of bimetallic composites when used for the removal of arsenic species. Thus, this work focused on the biosynthesis mechanism involved in the formation of a Fe/Cu bimetallic bio-composite (Fe/Cu-OC), and determination of the specific biomolecules in tea extract involved in biosynthesis, and identification of the reactive sites involved in the removal of As(V). FTIR , XPS, GC-MS, and LC-MS analysis of the main components of the tea extract proved that the surface of Fe/Cu-OC contained many different functional groups, including -OH, Fe/Cu-O, and O C-OH, which were mainly associated with theanine and caffeine complexes. SEM and TEM analyses indicated that Fe/Cu-OC had both crystalline and amorphous features with an average particle size of 366 ± 10 nm. A 97 % removal efficiency for As(V) was obtained by Fe/Cu-OC, suggesting that the surface contained numerous reactive sites, including unsaturated Fe and Cu complexes, as well as saturated benzene rings. Moreover, DFT calculations indicated that the Gibbs free energy changes for the preparation of Fe/Cu-OC were < 0, suggesting that in the composites biosynthesis was a thermodynamically favored spontaneous reaction. A biosynthetic mechanism for the formation of Fe/Cu-OC was proposed, involving a series of spontaneous coordination, redox, and organic adsorption reactions.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Lei Xiao,Chaowei Yuan,Peng Chen,Yongyi Liu,Jianping Sheng,Shihan Zhang,Fan Dong,Yanjuan Sun
Due to the intrinsic chemically inert CO2 with the dissociation energy of C═O bond as high as 750 kJ mol–1, low efficiency and selectivity have become the most significant restraints for the practical application of photocatalytic CO2 reduction. Renewing the electronic structure of adsorbed CO2 on the catalyst surface through a rational catalyst design is crucial to achieving performance improvement. Herein, we prepared ZnIn2S4 and Cu-substituted ZnIn2S4 containing both Lewis acid and Lewis base sites as a model system for investigating the activation of CO2 by M–S chemical bonds (M represents a metal site). The Cu–S chemical bond can effectively activate CO2 as a vital electron channel and lower the Gibbs free energy for generating the essential intermediate *COOH. Besides, the Cu0.7-ZnIn2S4 sample displays 74.8% selectivity for reducing CO2 to CO with a rate of 47.2 μmol g–1 h–1, roughly 7.14 times that of ZnIn2S4.
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DOI
高影响因子
Frontiers in Chemistry
·
2021
·
IF 5.221
Hu Qin,Qin Jie,Wang Xiao-Feng,Ran Guang-Ying,Wang Qiang,Liu Guang-Xiang,Ma Jian-Ping,Ge Jing-Yuan,Wang Hai-Ying
A non-enzymatic electrochemical sensor for glucose detection is executed by using a conductive metal–organic framework (MOF) Cu-MOF, which is built from the 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) ligand and copper acetate by hydrothermal reaction. The Cu-MOF demonstrates superior electrocatalytic activity for glucose oxidation under alkaline pH conditions. As an excellent non-enzymatic sensor, the Cu-MOF grown on Cu foam (Cu-MOF/CF) displays an ultra-low detection limit of 0.076 μM through a wide concentration range (0.001–0.95 mM) and a strong sensitivity of 30,030 mA μM−1 cm−2. Overall, the Cu-MOF/CF exhibits a low detection limit, high selectivity, excellent stability, fast response time, and good practical application feasibility for glucose detection and can promote the development of MOF materials in the field of electrochemical sensors.
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Qian Wang,Zhi Yu,Junting Feng,Paolo Fornasiero,Yufei He,Dianqing Li
The production of biofuel 2,5-dimethylfuran (DMF) from an important biomass platform of 5-hydroxymethyl furfural (HMF) involves a complicated reaction pathway due to the competition of C═O hydrogenation and C–O hydrogenolysis; however, the dependence of formed intermediates and catalytic sites needs to be further identified. Herein, we constructed a highly efficient and selective Cu/ZnO-Al2O3 catalyst via reduction of a CuZnAl-layer double hydroxide (LDH) precursor, aimed for studying the effect of Cu0/Cu+ species on forming different intermediates and their synergetic promotional effect on HMF hydrodeoxygenation. As expected, the dependence of formation of different intermediates on the Cu+/Cu0 ratio was observed; notably, Cu/ZnO-Al2O3 with higher Cu+/Cu0 ratio finally gave 90.1% DMF selectivity at 100% HMF conversion, more selective than CuNi/Al2O3 (59.6%) and Cu/MgO-Al2O3 (75.8%) references. By a combined study of in situ IR experiments, the observed correlation between the reaction intermediates and the Cu0/Cu+ site suggests that Cu0 tends to adsorb the C═O bond as well as hydrogen molecule, while the Cu+ site is preferable to adsorb and activate the C–O bond. With the synergy of dual active sites, the Cu/ZnO-Al2O3 catalyst showed both high activity and selectivity to DMF. This work provides deep insight into the nature of active Cu species in multiple functional group biomass platform transformation.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Kun Chen,Huihuang Fang,Simson Wu,Xi Liu,Jianwei Zheng,Song Zhou,Xinping Duan,Yichao Zhuang,Shik Chi Edman Tsang,Youzhu Yuan
The direct hydrogenation of CO 2 to methanol has become a very active research field because CO 2 can be prospectively recycled to mitigate greenhouse effect and store clean synthetic fuels. This reaction can be catalyzed by supported Cu catalysts and the catalysts display strong support or promoter effects. Sintering of Cu species accelerates the separation of Cu–oxide interfaces, reduces the active component, and diminishes the methanol selectivity. In this work, we report a Cu catalyst supported on La-modified SBA-15, where the Cu–LaO x interface is generated through the interaction of highly dispersed Cu nanoparticles with LaO x species bedded into the SBA-15 pore wall. The optimized Cu 1 La 0.2 /SBA-15 catalyst can achieve methanol selectivity up to 81.2% with no deterioration in activity over 100 h on stream compared with the La-free catalyst. A thorough study reveals that La species not only significantly improve the CO 2 adsorption but also enhance Cu dispersion to produce well-dispersed active sites. The H/D exchange experiments show that the methanol synthesis displays a strong thermodynamic isotope effect and the Cu–LaO x interface plays a crucial role for the methanol synthesis rate in CO 2 /D 2 feed. In situ DRIFTS studies reveal that *HCOO and *OCH 3 species are the key intermediates formed during the activation of CO 2 and methanol synthesis over the Cu 1 La 0.2 /SBA-15 catalyst.
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高影响因子
CARBON
·
2017
·
IF 6.337
Tingjun Fu,Xia Wang,Huayan Zheng,Zhong Li
A series of novel composite catalysts consisting of carbon spheres with encapsulated copper species were synthesized by incipient wetness impregnation . To improve catalytic activity , Cu location on the hollow carbon spheres was tuned by ultrasonic-assisted impregnation. The location, dispersion and chemical structure of copper species were characterized by X-ray diffraction, Temperature-programmed reduction, Transmission electron microscopy , N 2 -physisorption, Atomic absorption spectroscopy , X-ray photoelectron spectroscopy and dissociative N 2 O adsorption measurements. The results showed that hollow mesoporous carbon spheres have uniform mesopores, which were more favorable to the confinement and dispersion of the active species than solid carbon spheres. The catalyst with Cu species highly dispersed in the mesopores of hollow carbon spheres exhibited superior catalytic performance compared with those with Cu species located outside the support or inside the hollow interiors. The catalyst with ultrafine Cu particles of 2 nm in the mesopores of the 200 nm carbon sphere exhibited a dimethyl carbonate Space-Time Yield of 218.4 mg·g −1 cat· h −1 , much higher than traditional activated carbon and ordered mesoporous carbon supported Cu catalysts. Interestingly, copper species in the cavity showed high autoreduction ability in spite of poor dispersion after activation, and this catalyst is anticipated to achieve better activity by improving Cu dispersion.
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高影响因子
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