PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2017
·Vol. 19
·期 28
·18232-18242
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IF 4.123
Samrat Devaramani,Mahgoub Ibrahim Shinger,Xiaofang Ma,Meng Yao,Shouting Zhang,Dongdong Qin,Xiaoquan Lu
J- and H-aggregates of zinc tetraphenylporphyrin (ZnTPP) on carbon nanotube films (CNTFs) were prepared using the mixed solvent method. This resulted in completely different structures, such as the four-leaf clover and flower, on the CNTF, which were observed by recording SEM images. Characteristic changes in the electronic spectra of the ZnTPP monomer appeared when it underwent J- and H-aggregation. The measured photocurrent significantly varied for the same molecule when it was aggregated in two different ways on ITO and ITO/CNTF. The electron recombination resistance of the two aggregates, which was investigated using electrochemical impedance spectroscopy, was also different. The photocatalytic efficiency of the J- and H-aggregates was examined by performing methylene blue dye decoloration studies. In addition, a scanning electrochemical microscope was used to investigate the photoinduced charge transfer kinetics of the J- and H-aggregates at the electrode/electrolyte interface as a fresh attempt. The heterogeneous charge transfer constants for the J- and H-aggregates in the presence of light at varied intensities were calculated. Thereby, striking differences in the photophysical, photocatalytic, and photoelectrochemical properties of the J- and H-aggregates were visualized throughout our studies.
研究领域:
材料科学
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光化学
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纳米技术
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电化学
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可再生能源
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催化
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2018
·
IF 2.829
Xueting Lu,Yangyang Li,Wei Feng,Shuang Guan,Peipei Guo
In this report, the self-healable hydrogels containing hydroxypropyl guar gum (HPG), acrylamide (AM) and 3-acrylamidophenylboronic acid (AAPBA) were prepared through a facile strategy. The double bond in AAPBA could polymerize with AM to form copolymers. Moreover, the boronic acid groups of AAPBA can interact with cis-diol of HPG which make AAPBA act not only polymer but cross-linkers simultaneously connecting PAM and HPG chains. The mechanical strength of the hydrogels was systematically investigated as a function of AAPBA content, HPG content, AM content and pH. It was found the hydrogels exhibited higher stress, elongations and self-healing properties due to the synergistic interaction of H-bond and dynamic covalent phenylboronic (PBA)-diol ester bonds. Furthermore, the hydrogels showed yielding phenomenon depending on the content of AM and pH, which could play a vital influence on the crosslinking manners and density. The detailed discussions of the relationship between crosslinking manners and yielding phenomenon provide a better understanding on the appearance of yielding phenomenon and their correlation with hydrogel structure.
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CRYSTENGCOMM
·
2015
·Vol. 17
·期 11
·2376-2388
·
IF 4.034
Xiang-Sheng Zhai,Wen-Gang Zhu,Wei Xu,Ya-Jing Huang,Yue-Qing Zheng
Four new 3D uranyl complexes, [(UO2)2(H2O)(ipa)2]·9H2O (1), [(UO2)2(H2O)(nip)2]·H2O·Et3NH (2), [(UO2)2(H2O)(aip)2]·Et3NH (3) and [(UO2)(hip)]2·17H2O (4) (H2ipa = isophthalic acid, H2nip = 5-nitroisophthalic acid, H2aip = 5-aminoisophthalic acid, H2hip = 5-hydroxyisophthalic acid, Et3N = triethylamine), were hydrothermally synthesized. Structural analyses reveal that compounds 1–4 consist of pentagonal bipyramidal uranyl monomers bridged via acid inkers to form a structural motif, [(UO2)2L2], serving as the foundation of the 3D framework. Two structural motifs adopt different arrangement modes to connect to two types of chains. For 1–3, uranium atoms and carboxyl groups being from two types of chains respectively are coordinated to build similar 3D frameworks, while for 4, one type of chain links to the 3D architecture by the bond of the uranium atoms and –OH of the 5-hydroxyisophthalic acid ligand. The different guest molecules and structure assemblies displayed by the four compounds are a function of the variation of substituent groups of 5-X-1,3-benzenedicarboxylic acid (X = –H, –NO2, –NH2, –OH). Furthermore, the photocatalytic properties of 2 and 4 for degradation of rhodamine-B (RhB) upon xenon lamp irradiation have been examined. Elemental analysis, infrared spectroscopy, DRS and luminescence properties were also discussed.
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POLYMER COMPOSITES
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2024
·
IF 4.8
Xinyi Jing,Linggong Meng,Tong Liu,Xinming Ye,Shuai Yang,Zhichao He,Wensheng Wang,Jie Li,Yingchun Li
Achieving high thermal conductivity in composites with low filler content is a major challenge in current research. In this paper, polypropylene (PP) and polyamide 6 (PA6) were used as polymer matrix, and the hybrid thermal conductive filler, formed by hexagonal boron nitride (h-BN) and aminated carbon nanotubes (NH 2 -CNTs), was integrated into matrix for the fabrication of thermal conductive composites (PP/PA6/h-BN and PP/PA6/h-BN@CNTs) via two-step melt blending technology. The thermal conductive fillers were selectively distributed in a phase of the polymer matrix with a co-continuous structure, forming a thermal conductive path with a three-dimensional network structure. The results show that when the content of h-BN reaches 25 wt%, the thermal conductivity of the PP/PA6/h-BN and PP/PA6/h-BN@CNTs composites was 199% and 300% higher than that of PP/PA6, respectively. Through testing the volume resistivity of the composites, it was confirmed that PP/PA6/h-BN@CNTs composites maintain good electrical insulation. Both composites demonstrated remarkable thermal conductivity and outstanding electrical insulation. This research provides a facile way to prepare highly thermal conductivity polymer composites with excellent processing performances and electrical insulation. Highlights h-BN@CNTs hybrid fillers with sandwich structure were prepared. A two-step blending method was used to control the selective distribution of hybrid fillers in a phase of the polymer matrix with a co-continuous structure. The hybrid filler formed a thermal conductive path with a three-dimensional network structure in the collective. PP/PA6/h-BN@CNTs composites demonstrated remarkable thermal conductivity, outstanding electrical insulation and favorable processing performances.
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CEMENT & CONCRETE COMPOSITES
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2022
·
IF 9.93
Xing Ming,Qing Liu,Miaomiao Wang,Yongqing Cai,Binmeng Chen,Zongjin Li
Chloride-induced corrosion in reinforced concrete is a primary durability issue that causes large economic loss every year. To improve the intrinsic chloride binding capacity and realize a favorable corrosion protection of cement-based materials are thus crucial to prolong the service life of concrete structures. Here, alumina nano particles (ANPs) were incorporated to improve the chloride binding capacity of cement pastes in chloride solutions and the anti-corrosion performance of mortars under accelerated corrosion process. The ANPs facilitated the formation of alumino-ferrite-mono (AFm)-type phases, thereby improved the content of chemically bound chlorides. Solution calcium (Ca) ions benefited the chloride captured by calcium-(alumino-)silicate-hydrates (C-(A-)S-H) in the assistance of ANPs, especially at high initial chloride concentrations , and further evoked a pH-related chloride binding response. Moreover, the enhanced corrosion resistance was finally realized by incorporating appropriate amount of ANPs because of the filling and chemical effects induced low permeability of mortars. In general, the ANPs possess dual functions in the aspects of chloride binding and corrosion inhibition . These findings are expected to advance the design of high-durable cement-based materials serviced in the marine environment.
研究领域:
建筑材料
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土木工程材料
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腐蚀科学
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纳米材料应用
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混凝土耐久性
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
·
IF 9.6
Rajapriya Andavar,Mameng Yang,Cunpeng Duan,Anuj Kumar,Yanzhi Sun,Junqing Pan
Industrial-level alkaline water electrolysis requires high-efficiency catalysts to achieve rapid water dissociation and hydrogen intermediate migration at an ampere-level current density. However, conventional alloy catalysts lack spatially organized, abundant site functions, resulting in poor coupling between alkaline electrolysis steps. Here, we report a new NiCoFeCuMoW high-entropy alloy (HEA) catalyst prepared by pulse electrodeposition, featuring efficient mass and charge transport. The catalyst features a three-dimensional hierarchically porous framework with tailored surface atomic configurations and chemically differentiated multimetallic motifs, enabling abundant accessible active sites, accelerated transport, and cooperative regulation of reaction intermediates. Density functional theory (DFT) calculations show that Mo/W-richdomains preferentially facilitate H 2 O dissociation, whereas adjacent NiCoFeCuMoW ensembles optimize hydrogen diffusion and intermediate stabilization via regulated d-band states, thereby establishing an efficient dissociation-diffusion cascade. The NiCoFeCuMoW HEA delivers overpotentials of only 36 mV within the hydrogen evolution reaction (HER) while exhibiting 226 mV in the oxygen evolution reaction (OER) operating in alkaline electrolytes at 10 mA cm −2 . Amazingly, the cell delivers an ultra-low electrolyte potential of 1.57 V at 120 °C and 1 A cm −2 , owing to greatly enhanced charge-mass transport and perturbed hydrogen-bond networks in the over-boiling environment, providing a scalable HEA design strategy for ampere-level industrial water splitting. The boosted electrocatalytic acitivity of new HEAs alloy catalyst under over-boiling environment. Download: Download high-res image (204KB) Download: Download full-size image
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JOURNAL OF BIOSCIENCE AND BIOENGINEERING
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2019
·
IF 2.032
Xiaohong Lu,Juhua Chen,Linshu Jiao,Lei Zhong,Zhaoxin Lu,Chong Zhang,Fengxia Lu
Directed evolution methodologies have been used as promising strategies for improving the catalytic properties of many existing enzymes . In the presented work, this approach was applied to improve the enzyme activity of l -asparaginase I obtained from Bacillus megaterium H-1. After two rounds of error-prone polymerase chain reaction (epPCR) and two generations of sequential DNA shuffling , all of 5 different mutants showed a significant increase in the enzyme activity of l -asparaginase I, ranging from 6.27 to 22.78 IU/mL. Among these mutants, D-9B and DD-12G displayed the relatively high catalytic activity , which were 20.22-fold and 21.33-fold higher than the wild-type enzyme (WT), respectively. Furthermore, the catalytic efficiency ( k cat / K m ) of D-9B and DD-12G were also improved, which were 132.73 min −1 mM −1 and 146.39 min −1 mM −1 , respectively, in comparison to that of WT (3.39 min −1 mM −1 ). In addition, mutant DD-12G showed tolerance toward wider range of pH values and higher temperatures than its WT counterpart. Homology modeling of above two mutants reflected a reduction of hydrogen bonds and an introduction of flexible residues in the loops near the active catalytic site Thr15. These changes contributed to the flexibility of loops, which may lead to further enhancement in catalytic efficiency. Results also showed that approximately 88.5% (0.978 mg/kg) acrylamide could be removed from mutant DD-12G pre-treated fried potato chips. This study clearly shows that directional evolution methods can indeed be utilized to improve the activity of l -asparaginase, which could also provide research basis for future application in food industry.
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DALTON TRANSACTIONS
·
2014
·Vol. 43
·期 24
·9216-9225
·
IF 4.097
Qiong Wu,Tianfeng Chen,Zhao Zhang,Siyan Liao,Xiaohui Wu,Jian Wu,Wenjie Mei,Yanhua Chen,Weili Wu,Lingli Zeng,Wenjie Zheng
Two arene Ru(II) complexes coordinated by 2-(3-methoxyphenyl)imidazole[4,5-f][1,10]phenanthroline, [(η6-RC6H5)Ru(m-MOPIP)Cl]Cl (R = H, 1; R = CH3, 2), have been prepared under microwave irradiation; the crystal structure of 2 exhibits a typical “piano stool” conformation, with bond angles for N1–Ru1–Cl1 86.02 (14)° and N2–Ru1–Cl1 84.51 (14)°. The Ru–C distance for the Ru atom bound to the benzene ring is about 0.2178(8) nm, and the average Ru–N distance for Ru atom to the two chelating N atoms is about 0.2092(4) nm. The evaluation of in vitro anticancer activities revealed that these synthetic Ru(II) complexes selectively inhibited the growth of HepG2 hepatocellular carcinoma cells, with low cytotoxicity toward LO2 human normal liver cells. The results demonstrated that the complexes exhibited great selectivity between human cancer and normal cells by comparing with the ligand m-MOPIP. Furthermore, complexes 1 and 2 could bind to c-myc G4 DNA in groove binding mode in promising affinity, and the insertion of the methyl groups in the arene ligand contributed to strengthen the binding affinity. This was also confirmed by molecular docking calculation and 1H NMR analysis which showed that both 1 and 2 can bind in the loop constructed by A6–G9 and G21–A25 base pairs in c-myc G4 DNA to block the replication of c-myc oligomer. Taken together, these results suggest that arene Ru(II) complexes display application potential as small molecule inhibitors of c-myc G4 DNA.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Xu Huang,Xuezhang Xiao,Xuancheng Wang,Zhendong Yao,Jiahuan He,Xiulin Fan,Lixin Chen
Li–Mg–B–H reactive hydride composite (RHC) has attracted extensive attention over the past decades for its extremely high hydrogen storage capacity (11.5 wt%). But the sluggish desorption kinetics for the second step dehydrogenation reaction need to be further improved. Herein, short rod-like TMTiO 3 (TM = Co, Ni) bimetallic oxides , which contain two kinds of transition metal elements, were synthesized and introduced into Li–Mg–B–H RHC for the first time. The NiTiO 3 exhibits excellent catalytic effect on the hydrogen desorption kinetic performance of Li–Mg–B–H RHC, and the incubation period for the second step dehydrogenation reaction is eliminated completely by reducing the apparent activation energy for the generation of MgB 2 from 296 kJ/mol to 269 kJ/mol. The NiTiO 3 doped Li–Mg–B–H RHC can desorb about 9.0 wt% H 2 without obvious attenuation of kinetic performance in five cycles. Mechanism analyses reveal that the in-situ generated nano-sized MgNi 3 B 2 and TiB 2 species (∼5 nm) both meet the critical value ( < 10%) of the edge-to-edge matching model (5.77% for MgNi 3 B 2 and 2.22% for TiB 2 ), which play a significant role in supporting the nucleation of MgB 2 . Meanwhile, the extremely fine MgNi 3 B 2 and TiB 2 heterogeneous nucleation sites can inhibit the excessive growth for a single crystal nucleus of MgB 2 . The heterogeneous nucleation and grain refinement mechanisms caused by the novel bimetallic oxide could provide alternative insights into designing an in-situ generated nano-sized catalytic hydrogen storage system with enhanced kinetics and cyclic stability for hydrogen-fueled applications.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Kok Bing Tan,Pan Tian,Xinxin Zhang,Jian Tian,Guowu Zhan,Jiale Huang,Qingbiao Li
The present study developed bifunctional catalyst for CO 2 hydrogenation into dimethyl ether (DME), whereby it consists of Pd/In 2 O 3 for CO 2 hydrogenation into methanol, and H-ZSM-5 for methanol dehydration into DME. The catalyst development was focused on the synthesis of Pd/In 2 O 3 via a green and low-cost synthesis method of carbonized alginate templating. Thus, microspherical-confined nano-Pd/In 2 O 3 was formed, whereby the localized nucleation growth was coordinated by the chemically entrapped In 3+ via ionic bond in the well-distributed alginate structure. It was found that hydrothermal temperature plays a key role in the development of this catalyst structure. The optimum hydrothermal temperature is 160 °C, as it is able to produce the highest amount of methanol. This catalyst was further integrated with H-ZSM-5 via different integration manners. It was found that mortar mixed method produces the highest amount of DME, as the close proximity causes stronger ion-exchange mechanism between the catalyst components, which facilitates higher oxygen vacancy density in the bifunctional catalyst. Under the optimum Pd/In 2 O 3 : H-ZSM-5 (PdIn-160–12: H-ZSM-5) mass ratio of 4:1, the highest STY DME of 79.7 g DME kg cat -1 h −1 with CO 2 conversion of 9% and DME selectivity of 44.1% can be achieved. In addition, the STY DME can be maintained even in 60 h on stream, demonstrating the excellent stability and performance of microspherical-confined nano-Pd/In 2 O 3 /H-ZSM-5 bifunctional catalyst synthesized via carbonized alginate templating strategy.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Xiaoyu Wang,Mengchao Feng,Rui Cao,Yuchang Wang,Kai Ma,Jianbin Zhang
A new CeCO 3 OH@(hexagonal/cubic phases–CdS) (CeCO 3 OH@(H/C–CdS)) composite catalyst was facilely synthesized by a simple microinjection titration–stirring method, in which CdS nanoparticles were dispersed on the surface of CeCO 3 OH nanolines. The optimal conditions for the preparation of composite catalysts with high photocatalytic performance were determined by single-factor experiments and response surface experiments. Under these conditions, the degradation rate of 30 mL 2.000 g/L rhodamine B (Rh B) by CeCO 3 OH@(H/C-CdS) in a photocatalytic reaction for 1 h at 25 °C was up to 86.81 % and its degradation rate in a photocatalytic reaction for 150 min was up to 99.62 %. The degradation rate could be maintained above 80 % even after six times recycling. Especially, the photocatalytic degradation efficiency of 2.000 g/L Rh B on the composite catalyst under sunlight and at room temperature for 30 min reached 97.66 %. Meanwhile, the large size of CeCO 3 OH considerably alleviated the agglomeration of CdS, providing more adsorption and active sites for visible light-mediated degradation of Rh B. Importantly, the Z-scheme charge transfer realized by CdS and CeCO 3 OH enhanced the efficient separation of photogenerated electrons and holes, and successfully inhibited the recombination of photogenerated electrons with holes. At the same time, owing to the low energy band difference between the two phases of CdS, charge was transferred between the hexagonal and cubic phases, leaving more effective photogenerated charge to participate in the degradation of Rh B. The synergism of the heterophase junction and heterojunction and the presence of oxygen and sulfur vacancies considerably enhanced the degradation performance of the catalyst. Thus, this study provides a new strategy for the modification and enhanced visible-light catalysis performance of CdS-based catalysts.
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Molecular Catalysis
·
2019
·
IF 2.938
Qiaoyun Liu,Fei Liu,Yaru Zhang,Yang Su,Aiqin Wang,Tao Zhang
A highly active and robust catalyst composed of Ru nanoparticles highly dispersed on zeolite H-beta was developed for transforming furfural into 3-acetyl-1-propanol (3-AP) in good yield (81%)under mild conditions (80 °C, 1 MPa H 2 ). Both the support nature and the preparation methods had significant impacts on the dispersion of Ru, eventually on the yield of 3-AP. Ion-exchange method proved best for obtaining the highly active and selective catalyst for this reaction. Moreover, the catalyst can be regenerated easily by calcination and reduction. This catalyst was further explored for the one-pot conversion of xylose and xylan to 3-AP with a yield of 46% and 31%, respectively, thus opening a new feasible pathway from biomass to valuable fine chemicals.
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