INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2021
·
IF 5.816
Zhen Hu,Jian Chen,Peiyao Pan,Chao Liu,Jingming Zeng,Yang Ou,Xiaopeng Qi,Tongxiang Liang
Exploration for an earth-rich and competent electrocatalyst for the hydrogen evolution reaction (HER) is a significant and challenging approach to confronting the resources shortage and environmental crisis. Porous N-doped Mo 2 C@C (N-Mo 2 C@C) nanoparticles self-encapsulated in nanospheres are presented as a high-performing HER electrocatalyst fabricated through a one-pot solvothermal method followed by hydrogen calcination . Structural analyses show that acetamide can regulate the size of the nanospheres, provide a N source for doping and form porous structures composed of Mo 2 C, which suggests the exposure of extensive active sites as well as the contact and diffusion among the medium, electrodes, and gas. Theoretical calculations show that the N doping can enhance the activity of the Mo-C bond, reduce the energy of capturing hydrogen intermediates, and increase the catalytic conductivity. This work offers a simple and promising strategy to understand the catalytic mechanism required to optimize the activity of Mo-based electrocatalysts via N doping.
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高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
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2023
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IF 2.5
Zhang Xiaodong,Zhang Guofeng
The materials conventionally used for electrocatalysis in electrocatalytic Fenton applications are unstable and perform poorly. Based on the fact that iron and copper are common electrocatalytically active metals, they can provide abundant electron transfer capacity to facilitate electron transfer in the reaction and further promote the electrical conductivity of nitrogen-doped doped carbon materials Here, FeCu alloy/N-doped carbon composites (FeCu/N-C) are prepared for the electrocatalytic degradation of naproxen (NPX). Characterization results reveal that FeCu/N-C has more active sites, a larger surface area, and faster charge transport than N-doped carbon composites (N-C). Meanwhile, the increased number of active sites, surface area, and electron transport result in excellent NPX electrocatalytic degradation efficiency. The FeCu/N-C composite exhibits higher degradation efficiency than N-C under optimal conditions. In addition, the degradation efficiency is sustained at around 100% after five cycles. A detailed analysis of the mechanism reveals that 1 O 2 and ·OH are the primary active species responsible for NPX degradation through bursting studies. A potential pathway for the NPX degradation is proposed. This study provides a new and feasible method for developing carbon-based electrocatalysts to expand their applications in the environmental field.
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Environmental Science-Nano
·
2023
·Vol. 11
·期 1
·459-469
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IF 7.3
Hu Meng,Zhiwen Liu,Xiaoxin Wang,Liang Feng
Compared with carbon dioxide, fluorinated greenhouse gases (F-type gases), such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6), have a stronger greenhouse effect, and their global warming potential can reach thousands or even tens of thousands of times that of carbon dioxide. Thus, the rapid online accurate detection of fluorinated greenhouse gases is highly desired and it can provide a basis for the evaluation of the greenhouse effect and a yardstick for the formulation of emission reduction measures. Unfortunately, these highly noble chemical gas molecules, especially at trace concentration levels, are extremely difficult to detect with conventional rapid screening methods. The use of the most common gas sensing techniques, semiconducting metal oxides, in the detection of HFCs and PFCs has not appeared within the scope of our knowledge. Herein, we report a novel N-doped tin oxide semiconducting metal oxide prepared by using a facile hydrothermal method. The experimental characterization results showed that the as-prepared materials were uniform spherical nanoparticles. The doping ratio of N-doped tin oxide was further optimized, and gas-sensing tests using these materials were carefully conducted. The results showed that the sensor had good detection performance for F-type gases, represented by SF6, C2F6 and C2H2F4, including low working temperature (200 °C), high selectivity, good repeatability, relatively high response, and low limit of detection (LOD ∼7 ppb). To the best of our knowledge, this is the first report on an F-type gas sensor based on semiconductor metal oxide. The ultra-fine particle size and uniform morphology of spherical particles, high concentration of oxygen vacancy defects and N doping contribute to the excellent performance of the sensor.
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CHEMICAL ENGINEERING SCIENCE
·
2023
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IF 4.7
Xiaoxuan Li,Fei Wu,Wenhua Zhou,Chao Chen,Jianghao Wang,Bolong Li,Hao Chen,Jie Fu
Liquid organic hydrogen carriers have attracted significant attention for hydrogen storage and transportation and have been extensively investigated. Pd-based noble metal catalysts have been reported as some of the most active catalysts, however, achieving an optimal Pd utilization efficiency and stability remains challenging but significant. Herein, a PdCoO x -based bimetallic oxide catalyst was prepared and applied for the low-temperature dehydrogenation of dodecahydro- N -ethylcarbazole (12H-NECZ) to produce H 2 , utilizing the following advantages: (1) the activity of Pd was enhanced by introducing Co to form a PdCoO x bimetallic oxide site; (2) the electronic state of the catalyst was tuned based on the interfacial effect between the PdCoO x and Zr-C 3 N 4 supports. Thus, PdCo bimetallic oxide formation improved the electronic transfer rate and the interaction between the support and PdCoO x , thereby enhancing the catalytic dehydrogenation activity. Consequently, 12H-NECZ was completely dehydrogenated with 95.6 % selectivity at 140 °C for 8 h, with only 2.63 wt% Pd loading.
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COMBUSTION AND FLAME
·
2023
·
IF 4.4
Bingjie Chen,Peng Liu,Bingzhi Liu,Zhandong Wang,Xiang Gao,William L. Roberts
As a representative aromatic component of practical fuels, understanding the low temperature chemistry of 1,2,4-trimethylbenzene under the reaction environment of fuel mixtures is necessary to improve the ignition and combustion process . In this work, low temperature oxidation of 1,2,4-trimethylbenzene was examined in a jet stirred reactor with reactants of n-heptane and 1,2,4-trimethybenzene in a fuel mixture (1:1 in mole, 500–800 K, ϕ = 0.5, τ = 2.0 s, p = 1 bar). Chemical species and their mole fraction evolution with reaction temperatures were recorded by the time of flight molecular beam mass spectrometer using synchrotron vacuum ultraviolet radiation as photon ionization source. Molecular structures of 56 species were identified by comparing the species ionization energies and the photonionization efficiency curves. 25 chemical formula of monocyclic oxygenated aromatics and oxygenated polycyclic aromatic hydrocarbons (OPAH) are detected, and 12 of them are identified. Some of the OPAHs are more toxic than the polycyclic aromatic hydrocarbons, indicating the importance of revealing their formation pathways in low temperature oxidation of aromatics. Numerical simulations using the latest kinetic model from Lawrence Livermore National Laboratory well predict the mole fractions of the reactants and most intermediates, but many monocyclic oxygenated aromatics and OPAHs are missing. The detection and identification of key monocyclic oxygenated aromatics (e.g., peroxides, aldehydes, dialdehydes, and ketohydroperoxides of 1,2,4-trimethylbenzene) provide important clues to unravel the low temperature oxidation pathways of alkylated aromatics like 1,2,4-trimethylbenzene. For monocyclic oxygenated aromatics and OPAHs that are missing in the kinetic model, potential formation pathways were proposed based on the molecular structure information, which might be useful for future kinetic model development.
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ChemistrySelect
·
2023
·Vol. 8
·期 37
·e202302830
·
IF 2.1
Hongyan Guo,Shu Wang,Lian Duan,Yue Sun,Shuwei Chen
Graphical A method for the synthesis of Nitrogen-Doped Carbon quantum Dots (N-CQDs) with 4-aminosalicylic acid and tartaric acid is proposed. The synthesized N-CQDs exhibit strong fluorescence and good photostability and can selectively detect CN − in solution. Selective and sensitive detection of Cyanide (CN − ) is critical essential due to it is one of the most lethal chemicals and threat to human health. In this study, nitrogen-doped carbon quantum dots (N-CQDs) were synthesized by one-step hydrothermal method using 4-aminosalicylic acid and tartaric acid as raw materials. The prepared N-CQDs were spherical particles with good water solubility and uniform particle size distribution, the optimal excitation and emission wavelengths of N-CQDs were 495 nm and 514 nm, respectively. Based on the selective fluorescence quenching effect between CN − and N-CQDs, achieving accurate and rapid detection of CN − . Fluorescence quantum yield (PLQY) of N-CQDs is 39 %, and the other competing anions showed little or no interference to CN − . For highly sensitivity detections of N-CQDs under optimal conditions, the fluorescence quenching degree was linearly correlated with the CN − concentration in the range of 0–100 μM (R 2 =0.9929).
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JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2023
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IF 6.1
Wei Rong,Meili Ding,Pan Ma,Suyu Kong,Jianfeng Yao
Accumulation of atmospheric CO 2 poses a serious threat to the global environment, but there is still a lack of effective CO 2 catalytic conversion under mild conditions. Herein, multifunctional ZnO/N-doped porous carbon materials, ZNPC-X, were fabricated by pyrolysis of available pine pollen with melamine and zinc chloride . The optimized ZNPC-600 produced at 600 °C can work as an efficient photothermal catalyst towards CO 2 cycloaddition conversion with a high catalytic yield of 99% under mild conditions (0.3 W/cm 2 , 1 bar). Moreover, ZNPC-600 shows excellent recyclability after ten cycles and desirable performance even under simulated flue gas and after moisture treatment. Absorption spectra and time-dependent infrared images unveil that the intrinsically broad light absorption and high photothermal conversion efficiency are the major reasons for the high activity of ZNPC-600. Besides, photogenerated electrons can be transferred to CO 2 and activate it, while photogenerated holes can be used as Lewis acid to facilitate the ring opening of epoxides. In addition, the hierarchical pore structure and the synergy between ZnO and pyridine N also play a role in the mass transfer and activation of epoxides and CO 2 , respectively. This work provides a low-cost and facile solution to obtain catalysts derived from biomass for promoting CO 2 conversion.
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Stem Cell Research & Therapy
·
2021
·Vol. 12
·期 1
·1-14
·
IF 6.832
Zhang Jiayu,Lan Tingting,Han Xue,Xu Yuchan,Liao Li,Xie Li,Yang Bo,Tian Weidong,Guo Weihua
Background The low survival rate or dysfunction of extracellular matrix (ECM)-based engineered organs caused by the adverse effects of unfavourable local microenvironments on seed cell viability and stemness, especially the effects of excessive reactive oxygen species (ROS), prompted us to examine the importance of controlling oxidative damage for tissue transplantation and regeneration. We sought to improve the tolerance of seed cells to the transplant microenvironment via antioxidant pathways, thus promoting transplant efficiency and achieving better tissue regeneration. Methods We improved the antioxidative properties of ECM-based bioroots with higher glutathione contents in dental follicle stem cells (DFCs) by pretreating cells or loading scaffolds with the antioxidant NAC. Additionally, we developed an in situ rat alveolar fossa implantation model to evaluate the long-term therapeutic effects of NAC in bioroot transplantation. Results The results showed that NAC decreased H 2 O 2 -induced cellular damage and maintained the differentiation potential of DFCs. The transplantation experiments further verified that NAC protected the biological properties of DFCs by repressing replacement resorption or ankylosis, thus facilitating bioroot regeneration. Conclusions The following findings suggest that NAC could significantly protect stem cell viability and stemness during oxidative stress and exert better and prolonged effects in bioroot intragrafts.
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PubMed
高影响因子
NEW CARBON MATERIALS
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2021
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IF 1.905
Jing Zhang,Lianghao Song,Chenfei Zhao,Xiuping Yin,Yufeng Zhao
Although the Co and N co-doped carbon catalyst (Co-NC) has attracted much attention because of its low cost and the natural abundance of the dopants, it has a low oxygen reduction reaction (ORR) activity and a high selectivity for the two-electron (2e - ) reduction of oxygen to H 2 O 2 , which affects its use in fuel cells. Co-NC catalysts were prepared by the pyrolysis of a mixture of cobalt chloride and chitosan pretreated with zinc chloride at 650, 750 and 850 o C, followed by washing with nitric acid and annealing at 900 o C. The results indicate that zinc chloride helps the complexing of chitosan with Co 2+ , which is also a chemical activator that generates pores, and annealing caused the evaporation of the spherical Zn metal nanoparticles formed by the carbothermal reduction of Zn ions, leading to a unique porous structure of the catalysts with spherical pores filled with spherical carbon nanoparticles formed by the growth of nitrogen-doped carbon as a result of the Co catalyst. The degree of graphitization is also improved by the Co catalyst. The Co-NC catalyst obtained at a pyrolysis temperature of 750 o Cshows the same four-electron (4e - ) reduction of oxygen as a commercial Pt/C catalyst, and a significantly higher ORR catalytic activity, longer-term stability and better methanol tolerance than a commercial Pt/C catalyst. These are due to its large specific surface area, high contents of pyridinic nitrogen and graphitic nitrogen that disperse the Co species and its excellent electrical conductivity.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Yuming Tu,Hui Yu,Wei He,Zhiyong Zhou,Wei Liu,Fan Zhang,Yixin Qu,Zhongqi Ren
The separation of aromatic and alkane is one of the most important and challenge chemical separation process. This study reports the high-efficiency separation of aromatics/alkanes in the pervaporation process based on a series of novel ionic liquid gel membranes. The ionic liquid gel membrane was characterized by FT-IR, SEM, AFM, TGA, and XRD techniques. The results revealed that the IL was maintained in the three-dimensional structure of polymer support and the membrane kept its stability when the temperature was over 300 °C. The relevant parameters i.e. polymer concentration, IL concentration, IL type, film-forming temperature, membrane thickness, feed concentration, operating temperature and feed flow rate on membrane process were investigated. The optimal membrane was prepared when the P(VDF-HFP) and [Amim][Tf 2 N] concentrations were 15 wt% and 45 wt%, the film-forming temperature was 15 °C and the membrane thickness was 120 μm. When the initial toluene concentration was 50 wt% and the flow rate was 200 mL/min, the best flux (120 g·m −2 ·h −1 ) and separation factor (11.3) were observed at 25 °C. Moreover, the separation factor was over 10 and the flux maintained at the same level after working continuously for 30 h, which indicates that the membrane has good stability.
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Energy Storage Materials
·
2021
·
IF 17.789
Caixing Wang,Bo Yu,Yuzhu Liu,Huaizhu Wang,Zewen Zhang,Congxin Xie,Xianfeng Li,Huamin Zhang,Zhong Jin
Aqueous redox flow batteries (ARFBs) are regarded as promising candidates for large-scale energy storage. In particular, ARFBs based on organic redox-active species can largely reduce the capital cost and mineral resource requirements. However, the design of redox-active organic materials with desirable electrochemical performances needs to be further explored. Herein, we report a green and low-cost synthesis of a highly soluble N-alkyl-carboxylate-functionalized derivative of 2,6-diaminoanthraquinone, namely, N,N'-(9,10-anthraquinone-2,6-diyl)-di-β-alanine (DAEAQ), which exhibits a high voltage plateau and long cycling life when serving as an anolyte in ARFBs. The alkaline ARFBs based on DAEAQ anolyte and potassium ferrocyanide (K 4 Fe(CN) 6 ) catholyte deliver a high open-circuit voltage of 1.12 V at pH ≥12. When sandwiched with a custom highly-sulfonated and nonfluorinated cation exchange membrane , the as-prepared ARFBs achieve an excellent maximum power density of 0.34 W cm −2 and an optimal capacity retention rate of 99.86% day −1 . This work highlights the great potential of rationally designed anthraquinone derivatives in ARFBs for grid-scale renewable and sustainable energy storage applications .
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高影响因子
CARBON
·
2020
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IF 8.821
Qingwei Liu,Min Zeng,Jue Liu,Baiyu Guo,Xiaozhu Hao,Qian Cao,Yuchen Shang,Xin Sun,Jinzhang Liu,Xuexu Gao,jiheng Li,Jie Zhu,Xixiang Zhang,Ronghai Yu
Environment-friendly Fe-based material@N-doped carbon nanoparticles imbedded in polylactic acid (PLA) matrix are prepared and applied in microwave absorption field. In the synthesis process, polydopamine (PDA) in the precursor could rationally regulate the phases of the iron-based particles and carbon contents. It turns out that optimizing the chemical composition plays a vital role in modulating microwave absorption performance . For instance, the maximum reflection loss ( R Lmax ) for Fe@N-doped carbon particles (S-120) reaches −61.6 dB (12.56 GHz, 2.1 mm), and the effective bandwidth is 4.48 GHz (from 13.52 GHz to 18 GHz) with a thickness of only 1.7 mm. The excellent microwave absorption performance could be attributed to perfect impedance matching brought by the synergies of multiple components. Moreover, the microwave absorbers display not only high microwave absorption performance but also environment-friendly characteristics that can avoid leaving stubborn waste after failure. The preparation process of the composite is pollution-free and the PLA in the composite can almost be naturally degraded within one month under simulated marine environment. This work may provide a new perspective on preparing high-efficient functional materials which are also harmless to the environment.
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危险品化学品经营许可证（带存储）