CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Jianan Yu,Zhiliang Zhu,Hua Zhang,Yanling Qiu,Daqiang Yin,Yi Cheng,Shaobin Wang
Metal-free nanocarbons with versatile structural dimensions and unique properties are promising materials for remediation of polluted environment. In this work, a 3-dimensional (3D) interconnected porous N-doped carbon (CN-3) was synthesized by stepwise pyrolysis of dicyandiamide and nanocellulose, and a solid-state-growth and rolling-up mechanism was proposed for the stepwise transformation from stacking layered structures (melem and g-C 3 N 4 ) into CN-3 with 3D interconnected network nano-architectures. It was found that the functional carbons obtained at varying annealing temperature presented different activities in peroxymonosulfate (PMS) activation for endocrine-disrupting chemical (estrone) oxidation, showing temperature-dependent mechanisms from radical-dominated reaction to nonradical oxidation. CN-3 presented 100% estrone removal in 10 min, much higher than the layered carbons. In addition, CN-3 exhibited satisfactory stability during the catalytic reactions. Characterizations indicated that persistent free radicals on the layered carbons tended to induce radical reaction while graphitic structure and N in derived 3D carbons are more responsible for nonradical reaction. This work provides new insights to the relationship between the carbon structural transformation and catalytic PMS activation to induce different oxidative pathways, which facilitate the generation of a highly active and stable carbon-based catalytic system for organic degradation.
✓ 已验证
产品关联
DOI
高影响因子
ANALYST
·
2020
·Vol. 146
·期 1
·207-212
·
IF 3.978
Wenjie Jing,Xiangkun Cui,Fanbo Kong,Wei Wei,Yunchao Li,Louzhen Fan,Xiaohong Li
Identifying the species and concentrations of antioxidants is really important because antioxidants play important roles in various biological processes and numerous diseases. Compared with an individual sensor detecting a single antioxidant with limited specificity, a sensor array could simultaneously identify various antioxidants, in which 3–5 types of nanomaterials with peroxidase-like activity are absolutely necessary. Herein, as a single-atom nanozyme, Fe–N/C with oxidase-mimicking activity was applied to construct a triple-channel colorimetric sensor array: (1) Fe–N/C catalytically oxidized three substrates 3,3′,5,5′-tetramethylbenzidine (TMB), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and o-phenylenediamine (OPD) to produce blue oxidized TMB (oxTMB), green oxidized ABTS (oxABTS) and yellow oxidized OPD (oxOPD), respectively; (2) with oxTMB, oxABTS and oxOPD as three sensing channels, a colorimetric sensor array was constructed for simultaneously discriminating glutathione (GSH), L-cysteine (L-Cys), ascorbic acid (AA), uric acid (UA), and melatonin (MT), even quantifying concentrations (with GSH as a model analyst). The performance of the sensor array was validated through accurately identifying 15 blind samples containing GSH, L-Cys, AA, UA and MT in buffer solution and human serum samples, and also in binary and ternary mixtures. This work proved that fabricating a single nanozyme-based sensor array was a simplified and reliable strategy for simultaneously probing multiple antioxidants.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Kaihang Zhang,David Kujawski,Chris Spurrell,Dong Wang,Junchen Yan,John C. Crittenden
Polyfluoroalkyl Substances (PFAS) such as perfluorooctanoic acid (PFOA) are resistant to biodegradation leading to adverse health outcomes. Therefore, PFAS removal from drinking water is paramount. Liquid-liquid extraction processes can remove them from water; however, the hydrophobic and oleophobic properties of PFOA lead to the low extraction efficiency and severe emulsification , especially for the ppm-levels concentration of PFOA. Therefore, we introduced ionic liquid (IL) methyltrioctylammonium bis(trifluoromethylsulfonyl)imide ([A336][NTf 2 ]) as extractant into octanol. We found that using hexadecyl trimethyl ammonium bromide (CTAB) as an extractant caused severe and stable emulsion. In comparison, [A336][NTf 2 ] could suppress the emulsification with high extraction efficiency. The extraction performance of PFOA was examined as a function of various parameters. The results showed that the extraction efficiency was strongly dependent on the concentration of IL and aqueous pH. Further research revealed the extraction mechanisms at the molecular-level, and density functional theory (DFT) and molecular dynamic (MD) simulation agreed with the trends in the experiment. We determined that the extraction efficiency of PFOA from water could be up to 88.21 wt% for the optimized condition, indicating that the extraction system of [A336][NTf 2 ] + octanol was efficient for separating PFOA from the diluted aqueous solution.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Li Ren,Jiemei Zhou,Sen Xiong,Yong Wang
Capacitive deionization (CDI) is an energy-efficient and environmentally friendly electrochemical desalination technology which has attracted increasing attention in recent years. Electrodes are crucial to the performance of CDI processes, and utilizing a carbon-nanotubes (CNTs) membrane to fabricate electrodes is an attractive solution for advanced CDI processes. However, the strong hydrophobicity and low electrosorption capacity limit applications of CNTs membranes in CDI. To solve this problem, we introduce crystalline porous covalent organic frameworks (COFs) into CNTs membranes to fabricate N-doping carbon-nanotubes membrane electrodes (NCMEs). After solvothermal growth and carbonization, CNTs membranes are successfully coated with imine-based COFs and turned into integrated NCMEs. Comparing with the CNTs membranes, the NCMEs exhibit an ∼2.3 times higher electrosorption capacity and superior reusability. This study not only confirms that COFs can be used as high-quality carbon sources but also provides a new strategy to fabricate high-performance CDI electrodes.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Liang Cheng,Mengxiao Zhang,Chuanjie Fang,Weilin Feng,Liping Zhu,Youyi Xu
Loose nanofiltration (NF) membrane with pore radius approaching 1 nm and positive charges can be valuable alternative to commercial available negatively charged polyamide NF membrane in specific applications, such as removal of hardness and heavy metal ions and selective separation of dyes/salts mixture. In this work, positively charged poly( N -vinyl imidazole) (PVI) gel-filled loose NF membranes were developed by asymmetric gel-filling upon an asymmetric ultrafiltration (UF) support via UV-initiated surface grafting polymerization and post-quaternization. Compared to the polyamide NF membranes, these membranes displayed a comparable salt rejection ability due to their stronger Donnan exclusion effect. A rigorous three-parameter transport model (TPM) considering steric, Donnan and dielectric exclusion on ions partitioning via effective pore radius ( r p ), membrane charge density ( X d ) and averaged pore dielectric constant ( ε p ), was used to analyze the membrane parameters. Then the gel conformation model (GM) treating confined gel as semi-dilute polymer solution with a characteristic correlation length ( ξ ) was applied to analyze these gel composites. The results suggest that the gel polymer volume fraction ( φ ) is decisive in the gel mesh size (viewed as membrane pore size) and gel permeability. Surface porosity of the asymmetric UF base is a limiting factor in membrane permeability. The joint modelling analysis can clarify the membrane structure-properties relationship, performance limits and potentials of the gel-filled NF membrane and hence facilitate structure design and optimization.
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2020
·Vol. 23
·期 4
·884-891
·
IF 3.117
Changle Wang,Lipeng Zhang,Ping Yang
Transition-metal phosphides have been identified as effective materials for improving electrocatalytic hydrogen evolution. In this study, Ni2P, Co2P, and NiCoP yolk–shell structures were embedded in N- and P-doped carbon nanofibers (NPNFs) by controlling the heat-treatment procedure of the fiber precursors. The hydrogen evolution reaction (HER) activity of the samples was tested. The formation process of phosphides introduced a large number of surface defects that act as active sites to improve H2 evolution. NPNF embedding composite NiCoP particles exhibited better performance compared with Ni2P–NPNFs and Co2P–NPNF samples in acidic conditions. In the case of a molar ratio Ni : Co : P of 1 : 1 : 1, NiCoP-decorated NPNFs revealed the best HER performance, which is ascribed to the loading of NiCoP composite particles, which greatly increased the specific surface area. NiCoP–NPNFs exhibited overpotentials of 183 and 280 mV at current densities of 1 mA cm−2 and 10 mA cm−2, respectively, with a Tafel slope of 94.5 mV dec−1.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Dongxing Wang,Ying Wang,Xiaochen Wang,Funan Guo,Yuanqi Bai
As a promising alternative fuel with favorable properties and attractive prospects, the application of n-hexanol in diesel engines has aroused the interest of researchers. This study investigated the effects of mixing with n-hexanol on the morphology, nanostructure, graphitization, and oxidation reactivity of soot particles generated from a diesel engine. Experiments were performed on a turbocharged, four-cylinder direct-injection diesel engine fueled with D100 (neat diesel fuel), DH15 (15% n-hexanol and 85% diesel, v/v), and DH30 (30% n-hexanol and 70% diesel, v/v), respectively. Under the constant torque of 125 N·m, two typical speeds of 1370 and 2150 rpm were selected. Transmission electron microscopy (TEM), Raman spectroscopy (RS), and thermogravimetric analysis (TGA) were used to characterize particulate samples. TEM images showed that DH15 and DH30 particles had smaller primary particle diameters in comparison with neat diesel particles. Moreover, with the increase of the n-hexanol content in mixtures, the interlayer distance increased, indicating a more disordered nanostructure. RS results showed that soot samples generated from n-hexanol/diesel blended fuels had a lower degree of graphitization with larger ID1/IG and AD1/AG and more amorphous carbon with larger ID3/IG and AD3/AG. Based on TGA, it can be deduced that the DH30 soot sample obtained at the engine speed of 1370 rpm was easier to be oxidized in the DPF regeneration process for an 8.23% reduction in Tmax compared with D100 soot. Furthermore, activation energy of soots sampled at the engine speed of 2150 rpm decreased from 123.0 kJ/mol for D100 soot, to 109.6 kJ/mol for DH15 soot, and to 101.2 kJ/mol for DH30 soot, respectively. Regarding the effect of engine speeds on physicochemical characteristics of particles, results showed that the soot has higher oxidation activity under higher engine speed.
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Energy
·
2021
·
IF 7.311
Y. Su,C. Li,C. Yao,L. Xu,J. Xue,W. Yuan,J. Liu,M. Cheng,S. Hou
The Palladium (Pd) nanoparticles were immobilized on the boron (B), nitrogen (N) doped porous carbon (BNC-50) through replacing cobalt path at room temperature, which was derived from the high-temperature pyrolysis of the modified Zeolitic Imidazolate Frameworks (ZIF) composes coated with 5-boronoisophthalic acid. The Pd nanoparticles could be uniformly dispersed on the BNC-50 supports by replacement reaction to effectively avoid the Pd nanoparticles agglomeration. Meanwhile, the B, N doping can further grapple the palladium nanoparticles with luxuriant activity sites during the loading process. The highly order carbon frameworks also offer more porous paths and interspace to enhance the mass and charge delivery. Therefore, the synthetic catalysis of palladium nanoparticles immobilized on the porous B, N-doped carbon displays excellent activity (Pd/BNC-50) for ethanol oxidation reaction (EOR). The catalytic activities of the Pd/BNC-50 with peak current density (2638.41 mA mg −1 ) are 3.77 times than that of Pd/C in the basic reaction solution.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Wenjie Xue,Hongxia Liu,Baohua Mao,Honglei Liu,Minghuang Qiu,Chengguang Yang,Xinqing Chen,Yuhan Sun
Hydrogen is a promising candidate to replace the exhausting fossil fuels. However, it is still a big challenge for hydrogen storage. Liquid organic hydrogen carrier (LOHC), which possesses high safety and purity, easy transport and reversibility, is highly attractive for hydrogen storage. Herein we report a new reusable bimetallic Pd-Rh nanoparticles (NPs) catalyst with synergy effect, boosting both the hydrogenation of N-ethylcarbazole (NEC) and dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC), which allows multiple cycles of reversible high-weight% hydrogen storage and uptake in short reaction time. Various ex- and in-situ characterizations evidenced that the superior activity was attributed to the bimetallic Pd-Rh NPs cluster structure on the surface of γ-Al 2 O 3 support. The mechanism of NEC hydrogenation over the Pd-Rh catalyst was proposed and verified by density functional theory (DFT) calculations. Such a strategy can be extended to other LOHCs and sheds light onto the development of LOHCs as energy vectors.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2020
·
IF 3.306
Yongsheng Yang,Zhiduo Liu,Da Chen,Bingli Gu,Bo Gao,Zihao Wang,Qinglei Guo,Gang Wang
In this work, nitrogen-doped graphene quantum dots (N-GQDs) with high blue fluorescence are synthesized by the one-pot hydrothermal method from benzimidazoles. The as-fabricated N-GQDs possess a homogeneous size of 3.8 nm, good crystallinity, pip photostability, good water soluble, and a high quantum yield of about 25 %. In addition, it is found that the fluorescence of N-GQDs can be obviously quenched by tetracycline (TC) and elevated temperature. The detection of TC is implemented, with a detection limit of 0.21 μmol L −1 . For the temperature sensing, the fluorescence intensity shows a linear reduction between 25 °C and 100 °C. Moreover, reversible and stable abilities of temperature sensing are demonstrated. Owing to the superior optoelectronic properties, white light emitting diodes (WLEDs) using the N-GQDs as the phosphor are fabricated, and the CIE coordinates is (0.357, 0.315) with the color temperature of 4427 K. The results reported here will expand the multiple applications of N-GQDs in environment monitoring, biosensing engineering and optoelectronic devices.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Xiaoxing Lu,Shaoxia Xie,Jian Kuang,Hujun Xie
A comprehensive experimental investigation on the microstructures of microemulsion constructed with Gemini surfactant has been carried out. The structural transition of the microemulsion system, 14-4-14/1-propanol/ n -heptane/water, from water-in-oil (W/O) to bi-continuous (B.C.) has been characterized by electrical conductivity and cyclic voltammetry . Being a typically percolative system, spherical nanodroplets are observed in the W/O system, while interlinks of water and oil continuous phases are observed in the middle phase, as confirmed by cryo-TEM. Most importantly, the role of water is clearly revealed. Increasing the water content results in size enhancement as well as improvement of micropolarity and diffusion behavior. Results of DSC measurements suggest that free water dominates only at high total water content. The unfrozen water which is not detected by DSC takes a considerable amount in the W/O system at low total water content, while the interphasal water reaches over 50% of total water in the middle phase system.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Wenyan Wang,Yunlan Xu,Dengjie Zhong,Nianbing Zhong
Removal of complexation metal from plating effluents is always a problem. In this work, a core-shell structure zero-valent iron@nitrogen/graphite carbon nitride doped carbon (ZVI@C-N/g-C 3 N 4 ) composite was prepared and used to activate peroxymonsulfate (PMS) to treat complexation nickel simulated wastewater. Compared with ZVI, ZVI@C-N/g-C 3 N 4 significantly enhanced the efficiency and repeatability of PMS activation. For 45 min treatment, the removal efficiency of 50 ppm Ni-EDTA and Ni-citrate simulated wastewater reached 95.8 % and 100 %, respectively. The excellent performance of ZVI@C-N/g-C 3 N 4 is attributed to that the amino groups of nitrogen in C-N/g-C 3 N 4 shell can regulate the transmission rate of electrons released from ZVI core by adjusting the transmission rate of H + , so as to improve the electron utilization efficiency of PMS activation.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）