INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Xuancheng Wang,Xuezhang Xiao,Jiaguang Zheng,Zhouming Hang,Wenping Lin,Zhendong Yao,Meng Zhang,Lixin Chen
Magnesium borohydride , Mg(BH 4 ) 2 , is ball-milled with Ti nano-particles. Such catalyzed Mg(BH 4 ) 2 releases more hydrogen than pristine Mg(BH 4 ) 2 does during isothermal dehydrogenation at 270, 280, and 290 °C. The catalyzed Mg(BH 4 ) 2 also exhibits better dehydrogenation kinetics than the pristine Mg(BH 4 ) 2 . Based on kinetics model fitting, the activation energy ( E a ) of the catalyzed Mg(BH 4 ) 2 is calculated to be lower than pristine Mg(BH 4 ) 2 . During partial dehydrogenation , the catalyzed Mg(BH 4 ) 2 releases 4.23 wt % (wt%) H 2 for the second dehydrogenation at 270 °C, comparing to 4.05, and 3.75 wt% H 2 at 280, and 290 °C. The reversibility of 4.23 wt% capacity is also one of the highest for Mg(BH 4 ) 2 dehydrogenation under mild conditions such as 270 °C as reported. 4 cycles of Mg(BH 4 ) 2 dehydrogenation are conducted at 270 °C. The capacities degrade during 4 cycles and tend to be stable at about 3.0 wt% for the last two cycles. By analyzing the hydrogen de/absorption products of the catalyzed sample, Mg(BH 4 ) 2 is found to be regenerated after rehydrogenation according to Fourier Transform Infrared (FTIR) spectroscopy. Ti nano-particles can react with Mg(BH 4 ) 2 during ball-milling and de/rehydrogenation. The products include TiH 1.924 , TiB, and TiB 2 , which can improve the dehydrogenation properties of Mg(BH 4 ) 2 from a multiple aspect.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Yan Sang,Xi Cao,Lvxuan Wang,Gaofei Ding,Yingjie Wang,Deshuang Yu,Yanan Hao,Linlin Li,Shengjie Peng
Synthesis of highly efficient, non-noble and bi-functional electrocatalysts is exceedingly challenging and necessary for water splitting devices. In this work, three-dimensional spherical Ni(OH) 2 /NiCo 2 O 4 heterojunctions are prepared by a one-step hydrothermal method and the hybrids are explored as efficient electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in an alkaline electrolyte via tuning different Ni/Co atomic ratios of heterojunctions . The optimized Ni(OH) 2 /NiCo 2 O 4 (S (1:1)) exhibits high electrocatalytic activity with an ultralow over-potential of 189 mV at 10 mA cm −2 for the HER. With regard to the OER, the over-potential of the as-synthesized S (1:1) heterojunction is only 224 mV at the current density of 10 mA cm −2 . The improved catalytic performance of the Ni(OH) 2 /NiCo 2 O 4 heterojunctions is attributed to the chemical synergic combining of Ni(OH) 2 and NiCo 2 O 4 , large specific surface area for exposing more accessible active sites, and heterointerface for activating the intermediates that facilitates electron/electrolyte transport. The prepared catalyst exhibits good durability and stability in HER and OER catalyzing conditions. This study provides a feasible approach for the building of highly efficient bifunctional water splitting electrocatalysts and stimulates the development of renewable energy conversion and storage devices.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Wei Lai,Lihong Ge,Huaming Li,Yilin Deng,Bin Xu,Bo Ouyang,Erjun Kan
The electrochemical water splitting to produce H 2 in high efficiency with earth-abundant-metal catalysts remains a challenge. Here, we describe a simple “cyclic voltammetry + ageing” protocol at room temperature to activate Ni electrode (AC-Ni/NF) for hydrogen evolution reaction (HER), by which Ni/Ni(OH) 2 heterostructure is formed at the surface. In situ Raman spectroscopy reveals the gradual growth of Ni/Ni(OH) 2 heterostructure during the first 30 min of the aging treatment and combined with polarization measurements, it suggests a positive relation between the Ni/Ni(OH) 2 amount and HER performance of the electrode. The obtained AC-Ni/NF catalyst, with plentiful Ni–Ni(OH) 2 interfaces, exhibits remarkable performance towards HER, with the low overpotential of only 30 mV at a H 2 -evolving current density of 10 mA/cm 2 and 153 mV at 100 mA/cm 2 , as well as a small Tafel slope of 46.8 mV/dec in 1 M KOH electrolyte at ambient temperature. The excellent HER performance of the AC-Ni/NF could be maintained for at least 24 h without obvious decay. Ex situ experiments and in situ electrochemical-Raman spectroscopy along with density functional theory (DFT) calculations reveal that Ni/Ni(OH) 2 heterostructure, although partially reduced, can still persist during HER catalysis and it is the Ni–Ni(OH) 2 interface reducing the energy barrier of H∗ adsorption thus promoting the HER performance.
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CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Jiaguang Zheng,Xuancheng Wang,Xuezhang Xiao,Hao Cheng,Liuting Zhang,Lixin Chen
Two dual-cation transition metal fluorides K 2 TiF 6 and K 2 NbF 7 are introduced into Mg(BH 4 ) 2 by ball-milling to catalyze the dehydrogenation of Mg(BH 4 ) 2 . According to the DSC and TPD results, the onset dehydrogenation temperature of Mg(BH 4 ) 2 doped with K 2 TiF 6 and K 2 NbF 7 are remarkably reduced to 105.4 and 118.0 °C, respectively. Meanwhile, both the K 2 TiF 6 and K 2 NbF 7 catalyzed systems can release more than 6.4 wt% H 2 under 280 °C, showing an improvement in dehydrogenation kinetics. In addition, the reversible capacity of the Mg(BH 4 ) 2 –3%K 2 TiF 6 system is 2.7 wt% at 280 °C in 250 min, which is enhanced comparing to that of pristine Mg(BH 4 ) 2 . X-ray diffraction, Fourier-transformed infrared and 11 B nuclear magnetic resonance investigations reveal that the K 2 TiF 6 actually acts as a catalytic precursor to react with Mg(BH 4 ) 2 , forming active hydrides of KBH 4 and TiH 2 , which further serve as catalyzing agents to facilitate the re-generation of Mg(BH 4 ) 2 from intermediates under moderate conditions.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Min Hu,Jia-Xu Song,Shi-Tao Miao,Cheng-Kai Wu,Xing-Wen Gong,Hong-Ju Sun
Acetaldehyde dehydrogenase 2 (ALDH2) is a crucial enzyme in alcohol metabolism, and oral administration of ALDH2 is a promising method for alcohol detoxification. However, recombinant ALDH2 is susceptible to hydrolysis by digestive enzymes in the gastrointestinal tract and is expressed as inactive inclusion bodies in E. coli . In this study, we performed three rounds of rational design to address these issues. Specifically, the surface digestive sites of pepsin and trypsin were replaced with other polar amino acids, while hydrophobic amino acids were incorporated to reshape the catalytic cavity of ALDH2. The resulting mutant DE2–852 exhibited a 45-fold increase in soluble expression levels, while its stability against trypsin and pepsin increased by eightfold and twofold, respectively. Its catalytic efficiency ( k cat /K m ) at pH 7.2 and 3.2 improved by more than four and five times, respectively, with increased V max and decreased K m values. The enhanced properties of DE2–852 were attributed to the D457Y mutation, which created a more compact protein structure and facilitated a faster collision between the substrate and catalytic residues. These results laid the foundation for the oral administration and mass preparation of highly active ALDH2 and offered insights into the oral application of other proteins.
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PubMed
高影响因子
Journal of the Australian Ceramic Society
·
2019
·Vol. 56
·期 2
·795-801
·
IF 0.692
Zhang Tao,Wei Yaowu,Chen Junfeng,Li Nan
In spite of the advantages of CaO refractories, such as high refractoriness, potential to produce pure steel molten, and high alkaline corrosion resistance, their application has been limited due to its poor hydration resistance. Introducing additives to improve the hydration resistance of lime is a novel method. The influences of Mg(OH) 2 and sintering temperatures on the sintering and hydration resistance of CaO aggregates that were produced by thermal decomposition were investigated in this paper. The purpose of this work was to produce high-purity CaO raw material with high density, low porosity, well grain growth, and good hydration resistance economically. The sintered samples were characterized by bulk density, apparent porosity, surface appearance, and microstructure. The results indicated that (1) Mg(OH) 2 promoted the grain growth of CaO, reduced the apparent porosity, and improved the density of the specimens. The hydration resistance of the samples was increased. (2) Increasing the sintering temperature improved the hydration resistance of the specimens obviously in the experiment. (3) Grain size of CaO was more uniform with the increment of Mg(OH) 2 content, and the density of the compacts was improved.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2019
·
IF 3.218
Wei Chen,Jiayue Dong,Sihan Zhou,Chunyong Zhang,Degang Fu
1-naphthol (1-NAP) and 2-naphthol (2-NAP) are both hazardous pollutants which pose great threat to our living environment. In the current work, a comparative investigation on the electrochemical mineralization of 1-NAP and 2-NAP using boron-doped diamond (BDD) anode was presented. Experiments were carried out using synthetic 1-NAP or 2-NAP solutions containing Na 2 SO 4 as supporting electrolyte . A two-level factorial design methodology was adopted to optimize the mineralization process, six mathematical models were thus constructed and used to explore the structure-property relation involved. The results obtained suggested that 1-NAP was easier and faster to break down than 2-NPA under the same oxidation conditions, which were in line with the outcome obtained from cyclic voltammetry , HPLC and TOC measurements. To understand the destruction mechanism, the electron structures of 1-NAP and 2-NAP were further examined by the quantum chemistry calculations with density functional theory. It was also found that the results from frontier orbital analysis could well explain the differing mineralization performances recorded in BDD anode cell. Finally, with the aid of LC/MS analysis, the oxidation pathways of 1-NAP or 2-NAP on BDD anodes were proposed.
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REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Zhiguo He,Xuejiao Han,Hui Xie,Zifeng Yan,Bing Guo,Youwei Yao
Near-infrared (NIR) conjugated polymer nanoparticles (CPNPs) possesses advantages for bioimaging because of their merits in low autofluorescence interference, good biocompatibility, large light extinction coefficient, improved photostability, and facile functionalization capability. Different from conventional post-polymerization methods for fabricating NIR CPNPs, like nanoprecipitation, emulsion and solvent evaporation/miniemulsion, and self-assembly, herein, an efficient one-pot strategy by in-situ miniemulsion polymerization is demonstrated to synthesize CPNPs for NIR fluorescence imaging of cancer cells. Via adjusting the donor-acceptor strength , the new CP, poly(fluorene- alt -6-(2-ethylhexyl)-[1,2,5]thiadiazole[3,4- f ]benzotriazole) ( PFTA ), show absorption and emission maximum at 648 nm and 730 nm, respectively, which is much more red-shifted than its counterpart, poly(fluorene- alt -benzo-2,1,3-thiadiazole) ( PFBT ). DFT calculation demonstrates that the repeating unit of PFTA has a smaller dihedral angel to 33.2° and much reduced energy gap to 2.46 eV, as compared to that of PFBT NPs. Importantly, through controlling surfactant concentrations from 40 g·L −1 to 2.5 g·L −1 during the miniemulsion polymerization, the particles size can be accordingly changed from even 88 to 210 nm. Furthermore, the particles show extinction coefficient of 2.82 × 10 4 M −1 ·cm −1 at 648 nm, photoluminescence quantum yields c.a. 2.4% and fluorescence lifetime c.a. 1.26 ns, respectively. Moreover, the PFTA NPs exhibit biocompatibility, good colloidal stability and bright fluorescence signals to clearly pinpoint breast cancer cells, with a trend that smaller NP size, higher cellular uptake. This work demonstrates the promise of miniemulsion polymerization as a facile method to fabricate NIR CPNPs for bioimaging.
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JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 2
·1046-1056
·
IF 3.094
Xiaohui Feng,Le Wang,Ran Wei,Ziyan Wang
Non-contact temperature sensors based on the fluorescence intensity ratio (FIR) have been widely investigated owing to their high sensitivity and reliable real-time monitoring. Herein, the SiO 2 -coated LiY(MoO 4 ) 2 @SiO 2 :Er 3+ ,Yb 3+ phosphor was investigated as an optical thermometry material, which was synthesized using the conventional solid state reaction and coated by a facile wet chemical route. The effect of surface modification on FIR was systematically characterized by structural analyses and spectral measurements and the temperature-dependent up-conversion FIR was investigated from 303 to 603 K under a 980 nm laser excitation. The results showed that the FIR value was thermally stable and the SiO 2 coating led to a higher FIR sensitivity as well as a higher saturation threshold. This work would pave a way to design interesting optical thermometry materials in up-conversion phosphors with better properties.
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VIROLOGY
·
2022
·
IF 3.513
Haohao Yan,Zhicheng Liu,Gangan Yan,Xiaoli Liu,Xiaoping Liu,Yanchang Wang,Yunyu Chen
The global scourge of COVID-19 is a serious threat to public health, but effective therapies remain very limited for this disease. Therefore, the discovery of novel antiviral agents is urgently needed to fight against COVID-19. In the lifecycle of SARS-CoV-2, the causing pathogen of COVID-19, papain-like protease (PLpro) is responsible for the cleavage of polyprotein into functional units as well as immune evasion of vaccines. Hence, PLpro has been regarded as an attractive target to develop antiviral agents. Herein, we first developed a robust and simple sandwich-like fluorescence polarization (FP) screening assay for the discovery of PLpro inhibitors, and identified anacardic acid as a novel competitive inhibitor against PLpro in vitro with an IC 50 value of 24.26 ± 0.4 μM. This reliable FP screening assay could provide a prospective avenue for rapid discovery of antiviral agents targeting PLpro in a large-scale screening.
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JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Xintong Wang,Jiang Yang,Xu Chen,Wei Ding
The inhibition properties of 2-mercaptobenzimidazole (MBI) and its synergism with oleic imidazoline (OIM) for carbon steel in CO 2 -saturated brine solution were investigated by electrochemical, weight loss measurements, surface analysis and quantum chemical calculations. The effectiveness of MBI for OIM was also compared to the other sulfur-containing corrosion inhibitors such as 2-mercaptothanol (ME), mercaptoacetic acid (TGA), and thiourea (TU). The results show that a mixture of MBI and OIM gave a better synergistic corrosion inhibition than that of ME, TGA, and TU. OIM is protonated and coupled with MBI by hydrogen bonding to co-adsorb on the carbon steel surface. MBI adsorbs on Fe by a bidentate binding N S bridge connection, which effectively prevents the carbon steel from CO 2 corrosion.
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JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Caifeng Xiong,Jie Yuan,Zhiying Wang,Siyao Wang,Chenchen Yuan,Lili Wang
In this work, 2-methacryloyloxyethyl phosphorylcholine (MPC) was used as a ligand to prepare a novel mixed-mode chromatography (MMC) stationary phase by the thiol-ene click reaction onto silica (MPC-silica). It was found that this MPC-silica showed the retention characteristics of hydrophilic interaction chromatography (HILIC) and weak cation exchange chromatography (WCX) under suitable mobile phase conditions. In detail, acidic and basic hydrophilic compounds and puerarin from pueraria were separated quickly with HILIC mode. Meanwhile, six standard proteins were allowed to reach baseline separation in WCX mode, and protein separation from egg white was also achieved with this mode. In addition, reduced/denatured lysozyme could be refolded with the MPC-silica column. In the meantime, the MPC-silica has been applied for refolding with simultaneous purification of recombinant human Delta-like1-RGD (rhDll1-RGD) expressed in Escherichia coli . The results show that the mass recovery and purity of rhDll1-RGD could reach 63.4% and 97% by one step, respectively. Furthermore, the reporter assay results demonstrated that refolded with simultaneously purified rhDll1-RGD could efficiently activate the signalling pathway in a dose-dependent manner. In general, this MPC-silica has good resolution and selectivity in the separation of polar compounds and protein samples in different high-performance liquid chromatography (HPLC) modes, and it successfully achieved refolding with simultaneous purification of denatured protein.
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