Nanomaterials
·
2020
·Vol. 10
·期 6
·1035
·
IF 4.324
Xiang Nie,Guo Li,Zhao Jiang,Wei Li,Ting Ouyang,Jianfeng Wang
Exfoliation of two-dimensional boron nitride nanosheets (BNNSs) from parent bulk material has been receiving intensive attention because of its fascinating physical properties. Liquid exfoliation is a simple, scalable approach to produce single-layer or few-layer BNNS. In this paper, water/propanol co-solvent exfoliation of bulk boron nitride under the assistance of sonication was investigated in detail. Special attention was paid on the effect of raw bulk boron nitride size and co-solvent composition. The results show that sonication of small-size hexagonal boron nitride tends to generate large nanosheets, due to a predominant solvent wedge effect. In addition, it is found that the composition of water/propanol co-solvent has an important effect on exfoliation efficiency. Interestingly, although two isomers of 1-propanol (NPA) and 2-propanol (IPA) have the same molecular weight and similar surface tension, their aqueous solutions allow the formation of boron nitride nanosheets dispersion with markedly different concentrations. It is proposed that due to their spatial configuration difference, NPA with its longer molecular chain and fewer hydrophobic methyl group tends to form dynamic water-NPA clusters with larger size than water-IPA clusters. The hydrodynamic radius of the co-solvent “clusters” was calculated to be 0.72 nm for water/NPA system and 0.44 nm for water/IPA system at their maximum, respectively. Their size changes, represented by two curves, indicate a strong “cluster size” effect on exfoliation efficiency. Our work provides an insight into co-solvent exfoliation of hexagonal boron nitride and emphasizes the importance of co-solvent cluster size in exfoliation efficiency.Keywords:liquid phase exfoliation;boron nitride nanosheets;co-solvent cluster;size effect
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CRYSTENGCOMM
·
2021
·Vol. 23
·期 28
·4930-4937
·
IF 3.545
Wenhan Zhou,Yang Li,Lingcheng Zheng,Jun Liu,Ranran Tang,Kejian Shi,Yanyan Zhang
Considering their actual commercial large-scale applications, research on non-precious metal catalysts has garnered much interest. Particularly, metal–organic frameworks (MOFs) are used as non-precious metal catalysts because of their controllable, high surface area and rich N content. Herein, a MOF is transformed into a three-dimensional and porous Co–N–C catalyst by a one-step synthesis method and the joint action of Zn and PVP is reported. The catalyst exhibited efficient oxygen reduction reaction (ORR) performance (E1/2 = 0.83 V vs. RHE) and oxygen evolution reaction (OER) performance (Ej10 = 1.69 V vs. RHE). More meaningfully, the Zn–air battery (ZAB) assembled with the catalyst, exhibited superior 3100 min cycling charging/discharging stability and a high power density of 109.8 mW cm−2, compared with the Pt–RuO2 of 2600 min of cycling charging/discharging stability and power density of 96.1 mW cm−2. The solid-state ZAB based on the catalyst also showed excellent rechargeable flexibility and stability. Undoubtedly, this is a bifunctional oxygen electrocatalytic catalyst with practical application value.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Weiyi Chen,Bin Han,Yili Xie,Shujie Liang,Hong Deng,Zhang Lin
Converting carbon dioxide (CO 2 ) to multiple energy-rich chemicals by photocatalysis could validly mitigate the severe issues of climate changes and energy shortages. Exploring efficient catalysts for enhancing the performance of CO 2 photoreduction is still challenging. Herein, a novel three-dimensional hierarchical Co-Co layered double hydroxide/Ti 3 C 2 T X nanosheets (Co-Co LDH/TNS) nanoarray was successfully prepared via an in-situ MOF-derived strategy. This wise design rationally integrates the functional and structural merits of active Co species with conductive MXene to a hierarchical nanoarray architecture composed of ultrathin nanosheets, which can remarkably promote separation of photogenerated charge carriers and accelerate electrons transmission. Benefitting from these features, the hierarchical Co-Co LDH/TNS composites manifest significant enhancement on the CO 2 -to-CO evolving rate (1.25 × 10 4 µmol h −1 g −1 ) under illumination (>400 nm) with a high apparent quantum efficiency (0.92%) and excellent stability. Our work demonstrates that 3D hybrid structure composed of MXene species can serve as promising candidates for CO 2 photoreduction, providing fundamental guidance to improve photocatalytic performance by rational engineering of complex hierarchical architecture materials.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2016
·Vol. 18
·期 7
·1-11
·
IF 2.101
He Juan,Lu Xingping,Yu Jie,Wang Li,Song Yonghai
Abstract A novel Co(OH) 2 /glassy carbon electrode (GCE) has been fabricated via metal–organic framework (MOF)-directed method. In the strategy, the Co(BTC, 1,3,5-benzentricarboxylic acid) MOFs/GCE was firstly prepared by alternately immersing GCE in Co 2+ and BTC solution based on a layer-by-layer method. And then, the Co(OH) 2 with hierarchical flake nanostructure/GCE was constructed by immersing Co(BTC) MOFs/GCE into 0.1 M NaOH solution at room temperature. Such strategy improves the distribution of hierarchical Co(OH) 2 nanostructures on electrode surface greatly, enhances the stability of nanomaterials on the electrode surface, and increases the use efficiency of the Co(OH) 2 nanostructures. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and Raman spectra were used to characterize the Co(BTC) MOFs/GCE and Co(OH) 2 /GCE. Based on the hierarchical Co(OH) 2 nanostructures/GCE, a novel and sensitive nonenzymatic glucose sensor was developed. The good performance of the resulted sensor toward the detection of glucose was ascribed to hierarchical flake nanostructures, good mechanical stability, excellent distribution, and large specific surface area of Co(OH) 2 nanostructures. The proposed preparation method is simple, efficient, and cheap . Graphical Abstract
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SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Siqi Li,Liuting Wang,Xiaodan Zhang,Hongxiang Chai,Yuming Huang
The past few years have witnessed rapid development of nanozymes in various fields. However, analytical applications of oxidase nanozymes are limited. Here, a novel oxidase nanozyme was fabricated by one-pot pyrolysis of ZIF-67. Benefiting from self-template synthesis and a nitrogen-rich precursor, the resulting product is a highly N-doped hierarchically porous carbon with well-dispersed Co nanoparticles. It shows a typical oxidase mimicking property to efficiently catalyze oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB), 1,2-diaminobenzene, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt by oxygen to produce a color reaction without the need for H 2 O 2 . Reactive oxygen species (ROS) measurements indicate that 1 O 2 and O 2 − radicals are the main ROSs in the TMB–Co,N co-doped hierarchically porous carbon (Co,N-HPC) system. The high surface area and hierarchical pores of Co,N-HPC facilitate rapid diffusion of dissolved oxygen to the catalytic active sites, resulting in the novel and efficient oxidase nanozyme characteristic of Co,N-HPC. On account of the inhibiting effect of glutathione on TMB oxidation, a rapid and highly sensitive colorimetric assay is proposed for its detection. This assay has a linear concentration range from 0.05 to 30 μM and a limit of detection of 36 nM (3 σ ). The proposed method was successfully applied to glutathione quantification in biological samples.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Peng-Fei Qiu,Xiu-Niang Tan,Zai-Yin Huang,Yan Zhou
The low conductivity of many traditional metal–organic-framework (MOF)-based electrode limits their developments in the field of electrochemical energy storage and still of great challenge. The controllable preparation of various kinds of nanomaterials using thiol-functionalized MOF shows great prospects. In this work, a thiol-functionalized metal–organic framework sheet structure ( Co-MOF/NF ) on nickel foam was successfully prepared by in situ interfacial growth synthesis, which was transformed into its derivatives S-doped β-Co(OH) 2 nanoflowers Co-x/NF ( x = 1, 2 and 6) in different concentrations of KOH solutions through ion etching/exchange reaction. The pristine thiol-functionalized Co-MOF/NF and its derivatives Co-x/NF ( x = 1, 2 and 6) nanoflower-like arrays could be used as positive electrode materials for effective supercapacitors. Among them, the transformation of the nanoflower-like Co-1/NF electrode exhibits excellent electrochemical properties with high areal capacitance (1925 ± 23 mF/cm 2 at 1 mA/cm 2 ), good rate performance, excellent conductivity and decent cycling stability. The Co-1//AC ASC device provides a high energy density of 0.176 mWh/cm 2 (92.6 Wh/kg) at a power density of 0.745 mW/cm 2 (392.1 W/kg). And this Co-1//AC ASC device exhibits a good cycling stability and practical application in energy storage field. This study provides a new strategy for the pristine thiol-functionalized MOF and its conversion nanostructures for energy storage applications.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Xianyu Liu,Jing Li,Yingchun Xiao,Xiangcheng Dong,Lei Tao,Zhiyuan Liu,Zheng Liu,Jia Zhang,Shengjie Xu
The Li metal anode is regarded as the most potential electrode material in the next-generation energy storage system, because of the high energy density and specific capacity. However, the advancement of Li metal anode is restricted by the volume changing and dendrite growth. In this paper, the Co and Zn co-doped porous carbon framework (CF-CZ) derived from MOF structure was designed and produced to realize the dendrite-free Li metal anode. The porous structure could accommodate the deposited Li metal, which relaxes the pressure of electrode structure and relieves the volume changes. Meanwhile, the Co, Zn co-doping effectively improves the lithiophilicity of framework, which attracts Li + and decreases the nucleation barrier. Besides, numerous micropores of MOF structure could divide the Li + flux to reduce the local current density for dense sedimentation. With the synergies of co-doping and porous structure, the symmetric cell of CF-CZ shows better electrochemical performance (the overvoltage can be stable at 14 mV after 1200 cycles) than pure Cu foil, and the LFP cells deliver 116.4 mAh g −1 at 1 C after 200 cycles. As a consequence, the CF-CZ possesses the potential to be applied in Li metal anodes.
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International Journal of Electrochemical Science
·
2024
·
IF 1.3
Qijing Zhang,Kaijie Liang,Zhengri Shao,Jinguang Liang,Baoyi Ren
This article has been retracted: please see Elsevier Policy on Article Withdrawal ( https://www.elsevier.com/locate/withdrawalpolicy ). This article has been retracted at the request of the Editor-in-Chief. A post-publication investigation was prompted by concerns raised by the authors about the integrity of the results presented in their published article. Based upon the information provided by the authors and their subsequent assessment, the Editor-in-Chief lost confidence in the validity of the results reported in the paper. A decision to retract the article was therefore made in accordance with the journal's commitment to upholding the highest standards of scientific integrity and accuracy in published research.
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Processes
·
2024
·Vol. 12
·期 12
·2670
·
IF 2.8
Ke-Hong Chen,Ao-Tian Gu,Liang Zhang,Hao Tang,Zhi-Ming Zhang,Yi-Ming Zhou,Yu-Qi Cheng,Yi Yang
Chloramphenicol antibiotics (CAPs) are broad-spectrum antibiotics, and excessive consumption has led to increasingly dangerous residues in the environment. The accumulation of these highly toxic and difficult-to-biodegrade CAPs and their long-term exposure in ecological environments can pose insidious and long-term hazards to human health and aquatic organisms. In this study, co-carbon composite nanocatalysts (CoxZn10−x-NC) with many carbon nanotubes on the surface were prepared via the one-step pyrolysis of bimetallic CoxZn10−x-ZIF with different Co/Zn ratios and used for the degradation of trace amounts of CAPs in a water column. The microstructure and chemical composition of the prepared catalysts were fully characterized using SEM, TEM, and XPS. The CAP degradation experiments demonstrated that Co6Zn4-NC in CoxZn10−x-NC possessed the highest catalytic activity level, removing 100% of the CAPs in 60 min. The CAPs had a corresponding reaction rate constant of 0.22 min−1, and Co6Zn4-NC was able to completely mineralize 44.57% of them. Doping moderate amounts of Zn can effectively improve the carbon nanotube structure on the catalyst surface and promote the generation of monoatomic Co, thus improving catalytic activity. The results of the free-radical burst experiments and electron paramagnetic resonance (EPR) showed that the free-radical pathway mainly dominated within the Co6Zn4-NC+PMS system, in which SO4•−was the main ROS for CAP degradation.
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Metals
·
2025
·Vol. 15
·期 9
·930
·
IF 2.5
Jinhu Ju,Dan Huang,Haitao Xu,Duo Dong,Jiangpeng Lou,Yuan Xu,Jiao Shi,Liu Zhu
The fabrication of WC-based cemented carbides faced challenges including inhomogeneous composition and grain coarsening. To solve these problems, WC–Co cemented carbides were fabricated via spark plasma sintering (SPS) using core–shell WC–Co powders prepared by an electroless plating method. The effects of sintering pressure and Co content on the microstructure and mechanical properties of the cemented carbides were investigated. The results showed that, with increasing sintering pressure, the relative density of the sintered samples was improved (98.4–99.6%) while the grains were coarsened (0.94–1.07 μm). The optimal properties (fracture toughness 11.11 MPa·m1/2, and hardness 2100.3 HV30) were obtained when sintered with a pressure of 20 MPa. Grain coarsening at higher pressure (30 MPa) reduced the toughness of the cemented carbides. When the Co content was increased from 3 wt.% to 8 wt.%, fracture toughness was improved while the hardness of the cemented carbides was reduced, attributed to the intrinsic high toughness and low hardness of the Co phase. The WC–8 wt.% Co cemented carbides exhibited optimized synergic mechanical performance (hardness of 1874.2 HV30 and fracture toughness of 13.77 MPa·m1/2). This work elucidated the relationship between the key sintering parameters (pressure and Co content) and the microstructure and mechanical properties of the cemented carbides. The achievements obtained provide a theoretical foundation for high-quality fabrication of the WC–Co cemented carbides.
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Journal of Energy Storage
·
2024
·
IF 8.9
Huajing Zhang,Chao Xu,Xiangyu Sun,Bowen Xu,Zhirong Liao,Huawei Liu
Ca-based materials are considered to be promising energy storage materials for the 3rd generation concentrated solar power (CSP) plants due to their high energy storage density , high operating temperature , and low energy loss . However, the poor cyclic stability, low solar absorption capability, and slow reaction kinetics of conventional Ca-based materials seriously limit large-scale applications. Here, we successfully synthesized a Zr-Mn co-doped CaO-based composite, achieving good cyclic stability, enhanced solar absorption capability, and fast carbonation reaction kinetics simultaneously. The energy storage performance of 20Ca-0.5Zr-0.5Mn was evaluated at a high carbonation reaction temperature of 850 °C. Results showed that the performance decay of 20Ca-0.5Zr-0.5Mn was only 10.11 % over 30 cycles. By co-doping Zr and Mn elements, the carbonation reaction kinetics of CaO-based composites were promoted because of increased basicity and oxygen vacancies . Compared with pure CaO, the average solar absorptance of 20Ca-0.5Zr-0.5Mn was enhanced by about 376 %. Therefore, the proposed Zr-Mn co-doped CaO-based composite indicates the bright applied prospect in CSP plants for solar energy storage .
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POLYMER ENGINEERING AND SCIENCE
·
2024
·
IF 3.2
Mengen Liu,Qianyi Tang,Baijun Liu,Mingyao Zhang
Herein, the impact modifier of poly(butyl acrylate) grafted poly(styrene-co-acrylonitrile) (PBA-g-SAN) with 60% rubber content was prepared by emulsion grafting polymerization and subsequently blended with styrene–acrylonitrile copolymer (SAN) resin to construct acrylate styrene acrylonitrile (ASA) resins. The effects of acrylonitrile content of PBA-g-SAN copolymer and PBA size on the ASA resins' mechanical properties were investigated. Experimental results revealed that ASA resin's highest impact strength reached 27.75 kJ/m 2 . The lap shear adhesion test suggested that the PBA-g-SAN copolymer with 21% AN content exhibited excellent interfacial adhesion with SAN resin. The PBA-g-SAN particles with 100 and 400 nm poly (butyl acrylate) as core rubbers demonstrated a synergistic toughening effect for SAN resin. The high blackness ASA resin with excellent impact resistance was obtained when the 100 nm and the 400 nm poly (butyl acrylate) particle mass ratio reached 8/2. Highlights The ASA resin with 27.75KJ/m 2 impact strength was prepared. The synergistic toughening mechanisms were investigated. The high blackness ASA resin was constructed.
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