Catalysts
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2020
·Vol. 10
·期 3
·303
·
IF 3.52
Yaodan Wang,Hongyan Pan,Qian Lin,Yongyong Shi,Jiesong Zhang
Hydrogen peroxide (H2O2), as a clean and green oxidant, is widely used in many fields. The direct synthesis of H2O2(DSHP) from H2and O2has attracted most research interest because it relates to a facile, environmentally friendly, and economic process. Yolk–shell Pd-M@HCS (hollow carbon sphere) (M = Co, Ni, Cu) nanocatalysts, in which the bimetal nanoparticle is the core and porous carbon works as the shell layer, are reported in this work. It was found that catalytic activities were enhanced because of the introduced M metals. Additionally, the different mass ratios of Pd to Co (mPd/mCo) were further investigated to improve the catalytic performance for the DSHP. When mPd/mCo was 4.4, the prepared Pd-Co@HCS-(4.4) catalyst, with an average Pd nanoparticle size of 7.30 nm, provided the highest H2O2selectivity of 87% and H2O2productivity of 1996 mmolgPd−1·h−1, which were increased by 24% and 253%, respectively, compared to Pd@HCS.Keywords:direct synthesis of hydrogen peroxide;Pd-based catalyst;yolk–shell structure
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Zhicheng Xu,Yuran Li,Junxiang Guo,Jin Xiong,Yuting Lin,Tingyu Zhu
In this work and for the first time, an alkali metal potassium (K) as a promoter was loaded on an activated carbon (AC) to be used for selective catalytic reduction of NO from industrial flue gas. The denitrification activity of K-modified AC samples was investigated and compared with those of acid- and Cu-modified AC samples. The three modifications can enhance the denitrification activity of AC samples. To investigate the enhanced mechanisms of denitrification and SO 2 resistance, various AC samples were characterized by SEM, EDX, XRF, ICP, XRD, N 2 physisorption, H 2 -TPR, XPS, in situ DRIFTS and TPD. For the acid modification, the content of phenolic hydroxyl increases and then promotes the adsorption of NH 3 . For the loading of Cu, the appearance of Cu 2+ /Cu + sites with high catalytic activity promotes NH 3 and NO adsorption and changes the reaction pathway. For the loading of K, the adsorption capacity for NO increases nearly 12 times higher than that on Raw-AC, of which 85.0% is chemical adsorption. Moreover, three kinds of active nitrate species additionally forms, including nitro compounds, monodentate nitrate and nitrous oxide, which promote the denitrification reaction path. AC-Cu has poor sulfur resistance due to the sulfation of Cu, while AC-K show good sulfur resistance due to the enhanced adsorption of NO. The catalytic dissociation activity of N 2 O on AC-K makes the formation and decomposition of N 2 O into a dynamic equilibrium. As a result, AC-K has a high N 2 selectivity , while AC-Cu has poor N 2 selectivity.
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Sustainable Energy & Fuels
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2020
·Vol. 4
·期 6
·2937-2949
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IF 5.503
Xin Hu,Xiaosong Hu,Qingxin Guan,Wei Li
Converting CO2 to CO via the reverse water gas shift (RWGS) reaction is an important route to reducing greenhouse gas emissions, and catalysts using copper and zinc as active components have been extensively studied for this reaction. Herein, the coordination and acid etching of trimesic acid (H3BTC) were used to assemble and regulate the Cu and ZnO components in the catalyst. First, Cu-HKUST-1 was synthesized by the self-assembly of H3BTC and copper ions, which limited the sintering and agglomeration of Cu nanoparticles in the subsequent carbonization and self-reduction process. Second, ZnO particles were etched by H3BTC to form the complex of H3BTC with Zn and to redisperse Zn species. Under the dual action of H3BTC, carbon-coated bimetal nanoparticles with a size of 2–6 nm were obtained on the fumed silica after pyrolysis at high temperature. The prepared Cu@C–ZnO/SiO2 catalyst can achieve 31.4% CO2 conversion and 99% CO selectivity in RWGS reaction in a fixed bed reactor at 400 °C and 3 MPa. Besides, we also found that the molar ratio of Cu/Zn, metal components, and the introduction order of H3BTC all affected the structure and composition of the catalyst, thus affecting the catalytic activity. This study provides an excellent strategy for the design and synthesis of catalysts containing copper and zinc components.
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Journal of Materials Chemistry A
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2020
·Vol. 8
·期 11
·5699-5708
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IF 11.301
Xin Qian,Dongyang Wang,Yang Zhang,Haijun Wu,Stephen J. Pennycook,Lei Zheng,Pierre F. P. Poudeu,Li-Dong Zhao
The metallic elements with a small atomic radius can not only compensate for the intrinsic vacancies to improve the carrier mobility, but also can form interstitials to reduce lattice thermal conductivity. In this work, we investigate the contrasting roles of three different metallic elements with small atomic radius on the thermoelectric properties of n-type PbM0.01Se (M = Cu, Zn, Ni). We find that all the metallic elements can increase the carrier concentration as electron donors and improve the electrical transport properties. In addition, the lattice thermal conductivity of PbSe can be significantly decreased through the formation of interstitials by the incorporated extra metallic elements. We also find that the PbCu0.01Se sample exhibits a unique and complex behavior compared with the other samples due to the diffusion and the thermally activated oxidation of Cu+ ions. When the temperature increased to 673 K, the carrier concentration of PbCu0.01Se sample increases suddenly and continues to increase by nearly two folds, which we ascribe to the release of 3d orbital electrons in Cu+ ions. This results in a strong decoupling of the charge and heat transport in the material, which can be manifested by the overestimation of the electronic thermal conductivity when assuming strong electron–phonon coupling in Wiedemann–Franz law. A maximum ZT of ∼1.6 can be reached at 773 K and the average ZT of ∼0.96 can be achieved in PbCu0.01Se. Our results demonstrate the exceptional contrasting behavior of Cu in PbSe by comparing with Zn and Ni, and the thermoelectric performance of n-type PbSe can be enhanced through the introduction of extra metallic elements with small radius.
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Catalysts
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2020
·Vol. 10
·期 5
·533
·
IF 3.52
Jinjun Wen,Chunlei Huang,Yuhai Sun,Long Liang,Yudong Zhang,Yujun Zhang,Mingli Fu,Junliang Wu,Limin Chen,Daiqi Ye
CO2hydrogenation to methanol is one of the main and valuable catalytic reactions applied on Cu/ZnO-based catalysts; the interface formed through Zn migration from ZnO support to the surface of Cu nanoparticle (ZnOx-Cu NP-ZnO) has been reported to account for methanol synthesis from CO2hydrogenation. However, the accompanied reverse water gas shift (RWGS) reaction significantly decreases methanol selectivity and deactivates catalysts soon. Inhibition of RWGS is thus of great importance to afford high yield of methanol. The clear understanding of the reactivity of RWGS reaction on both the direct contact Cu-ZnO interface and ZnOx-Cu NP-ZnO interface is essential to reveal the low methanol selectivity in CO2hydrogenation to methanol and look for efficient catalysts for RWGS reaction. Cu doped plate ZnO (ZnO:XCu) model catalysts were prepared through a hydrothermal method to simulate direct contact Cu-ZnO interface and plate ZnO supported 1 wt % Cu (1Cu/ZnO) catalyst was prepared by wet impregnation for comparison in RWGS reaction. Electron paramagnetic resonance (EPR), XRD, SEM, Raman, hydrogen temperature-programmed reduction (H2-TPR) and CO2temperature-programmed desorption (CO2-TPD) were employed to characterize these catalysts. The characterization results confirmed that Cu incorporated into ZnO lattice and finally formed direct contact Cu-ZnO interface after H2reduction. The catalytic performance revealed that direct contact Cu-ZnO interface displays inferior RWGS reaction reactivity at reaction temperature lower than 500 °C, compared with the ZnOx-Cu NP-ZnO interface; however, it is more stable at reaction temperature higher than 500 °C, enables ZnO:XCu model catalysts superior catalytic activity to that of 1Cu/ZnO. This finding will facilitate the designing of robust and efficient catalysts for both CO2hydrogenation to methanol and RWGS reactions.Keywords:reverse water–gas shift reaction;CO2hydrogenation to methanol;Cu doping;direct contact Cu-ZnO interface;ZnOx-Cu NP-ZnO interface
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APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
S.Y. Qian,Z.H. Xu,H.N. Xie,C.S. Shi,N.Q. Zhao,C.N. He,E.Z. Liu
We investigated the atomic and electronic structures and interface interaction of graphene/copper interface with rare earth elements (REEs) modified using density functional theory. The effect of interface interaction enhancement induced by interfacial modification is revealed, which results in significant improvement of the mechanical properties of graphene/copper. Thereby, we applied a novel strategy to incorporate Y element at the interface of graphene nanoplatelets/copper (GNPs/Cu) to improve mechanical properties of composites. Tensile tests demonstrated that the yield strength of composites increases by 95.4% via very low fraction (0.2 wt%) of Y modification with elongation comparable to Cu, which exhibits excellent matched relationship between strength and ductility. Simultaneously, the composite equips with improved electrical conductivity compared with that of the matrix. We illustrated the strengthening effects of REEs modification at the interface that give rise to the effective load transfer, in consistence with the theoretical predication. Furthermore, the GNPs/Cu composites with the interface Ce/Sc elements modified were also fabricated, both of which showed excellent strength-ductility combination. Therefore, the universality of the present method is verified for the preparation of metal matrix composites with excellent mechanical properties through interface modification with REEs.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2020
·
IF 3.807
Fuling Zhou,Chao You,Qiang Wang,Yilin Chen,Zhipeng Wang,Zuoping Zeng,Xuping Sun,Ke Huang,Xiaoli Xiong
A novel highly sensitive non-enzymatic glucose sensor is constructed based on an ultrafast synthesized amorphous NiCu-OH film coated Cu(OH) 2 nanorod array grown on copper foam (NiCu-OH@Cu(OH) 2 NRA/CF). The synthesized (NiCu-OH@Cu(OH) 2 NRA/CF) has abundant catalytic activity and good catalytic performance for the electrochemical detection of glucose in alkaline conditions. Sensitive and selective voltammetric detection of glucose is demonstrated. The linear range extends from 100 nM to 1.5 mM, the detection limit is 32 nM, and the sensitivity is 6560.3 μA mM -1 cm -2 . The method is applied to the determination of nitrite in human blood serum.
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Advanced Materials Technologies
·
2020
·Vol. 5
·期 8
·2000260
·
IF 5.969
Zhiyong Liu,Xingyue Liu,Bo Sun,Xianhua Tan,Haibo Ye,Jianxin Zhou,Zirong Tang,Tielin Shi,Guanglan Liao
Photodetectors are essential parts of wireless optical communication system for obtaining high fidelity signal transmission, which mainly relies on expensive and energy-consuming Si, GaN, and InGaAs based photodiodes. The emerging organic–inorganic metal halide perovskite materials, with the merits of low-cost, strong optical absorption, superior charge transport, and so on, are widely investigated in photodetection applications. Herein, a Cu ion induced p-type doping strategy for perovskite film is proposed to facilitate hole transport, passivate trap states, avoid charge accumulation, and suppress recombination of photogenerated carriers, contributing to an enhanced photoelectric performance for self-powered hole-conductor-free devices. The optimal device shows a highest responsivity of 0.37 A W −1 , detectivity of 1.06 × 10 12 Jones, linear dynamic range of over 101 dB, and an ultimate photoresponse rate approaching 5 µs. Moreover, an optical communication system integrated with the perovskite photodetector as light signal receiver for transmitting digital signals is demonstrated, in which characters can be transmitted accurately, and audio signal is recovered with high fidelity. The results suggest that with proper chemical modification, perovskite materials are promising alternative to inorganic semiconductors for efficient photodetection in advanced integrated optical communication system.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2020
·Vol. 167
·期 12
·127501
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IF 3.721
Luo Wei,Ji-Hui Li,Chao Chen,Qian Lv,Ruitao Lv,Liqiang Ma,Wanci Shen,Feiyu Kang,Zheng-Hong Huang
The preparation of substrate with high specific surface area and conductivity is very important in the development of non-enzymatic glucose sensors. This study presents a non-enzymatic glucose sensor electrode based on a hybrid reduced graphene oxide (rGO) and carbonized silk fabric (CSF) substrate obtained by immersing silk fabric in a graphene oxide solution and carbonizing at 950 °C in an Ar atmosphere, and then decorating the rGO/CSF surface with Cu nanoflowers by electrodeposition. The optimum Cu-rGO/CSF sensor electrode exhibits high glucose sensitivities of 6613.3 μA mM−1 cm−2 and 1541.7 μA mM−1 cm−2 with linear responses over separate glucose concentration ranges of 0.05–4.0 mM and 4.0–7.0 mM due to the rGO/CSF substrate has high specific surface area, good conductivity and the Cu nanoflowers have high catalytic activity. The electrode also provides a lower limit of detection of 2.27 μM at a signal-to-noise ratio of 3 and high stability in the air. These results demonstrate that the proposed electrode material facilitates the development of simple and accurate non-enzymatic glucose sensors.
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Materials
·
2020
·Vol. 13
·期 9
·2033
·
IF 3.057
Yongzhen Lei,Long Mao,Jin Yao,Zhihan Li
Poly(lactic acid) (PLA) represents one of the most promising and attractive bio-based polymers for green packaging. However, toughness, gas barrier and antibacterial properties of pure PLA films cannot compete with those of traditional petroleum-based active packaging plastics. To fill this gap, utilization of excellent chelating properties of phytic acid (PA), functionalized layered double hydroxides (LDHs@PA-Cu(II)) was firstly synthetized via facile deposition and chelation of one-step assembled PA-Cu(II) coordination compounds on the surface of layered clay. Furthermore, LDHs@PA-Cu(II)/PLA nanocomposites were prepared by blending LDHs@PA-Cu(II) and pure PLA via solution casting evaporation process. After adding only 1 wt % LDHs@PA-Cu(II), elongation at break and tensile strength increase by 53.0% and 18.9%, respectively, and the oxygen relative permeability decreases by 28.0%. Due to the strong interface interaction and heterogenous nucleation, the reinforcement effect of LDHs@PA-Cu(II) at low loadings is remarkable. Meanwhile, owing to the antibacterial activity of PA-Cu(II) coatings, the antibacterial rate (against Escherichia coli) of LDHs@PA-Cu(II) exceeds 99.99%. Furthermore, the corresponding LDHs@PA-Cu(II)/PLA nanocomposites also show outstanding antibacterial properties, which will be a promising candidate for active packaging application.Keywords:layered double hydroxides;phytic acid;antibacterial activity;polylactic acid;barrier properties
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PubMed
高影响因子
Journal of CO2 Utilization
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2019
·
IF 5.189
Yuhai Sun,Chunlei Huang,Limin Chen,Yujun Zhang,Mingli Fu,Junliang Wu,Daiqi Ye
Plate-like ZnO, dominantly exposed (002) polar facet, supported Cu catalysts were prepared by impregnation method as model catalysts for CO 2 hydrogenation to methanol under the real reaction conditions. The catalysts were thoroughly characterized by Scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), in situ Raman spectra , Temperature-programmed reduction (H 2 -TPR) and CO 2 Temperature-programmed desorption (CO 2 -TPD). Catalyst microstructures can be obviously tuned through the increasing of Cu content, interface constituted by Cu-Plate ZnO direct contact, interface constituted by Cu (on ZnO) covered by migrated ZnO x and interface constituted by isolated Cu nanoparticles covered by migrated ZnO x . These microstructures displayed different catalytic performance for CO 2 hydrogenation to methanol; among them, interface caused by the migrated ZnO x covered Cu nanoparticles should play vital roles for methanol production.
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ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Jianbin Lin,Han Fang,Xianhua Tan,Bo Sun,Ziyi Wang,Huidan Deng,Huan Liu,Zirong Tang,Guanglan Liao,Tielin Shi
Humidity sensors have attracted intense interest in various fields because of the importance of humidity detection. Different methods have been adopted to enhance sensing performances of humidity sensors, while it is challenging for researchers to avoid the invalidation of the sensors after being wet. Here, we, for the first time, introduce self-assembly MoS2/Cu(OH)2 nanowires fabricated by liquid self-spreading–coating–evaporating as sensing materials and present MoS2/Cu(OH)2 nanowire-based quartz crystal microbalance gamut humidity sensors with superior sensitivity and self-recovery ability. The sensors deliver a remarkable sensitivity (60.8 Hz/% RH) under a wide range (0–97% RH) with fast response (1.9 s)/recovery time (3.8 s) and upgrade self-recovery ability that can maintain their original performances even after being wet, frozen, and heated or immersed in water. The sensors are also employed to monitor water counting, dew alarming, and human breathing (within 4 s), further showing their ultrahigh sensitivity for water molecules. The underlying humidity-sensing mechanism is interpreted by density functional theory calculations and in-situ Fourier transform infrared spectra experiments adequately, revealing that the high sensing performances are attributed to abundant adsorption sites and physisorption of water molecules. Our work proposes a strategy for transferring materials to arbitrary nanostructures swiftly and demonstrates new perspectives for highly sensitive humidity detection as well as self-recovery ability.
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