CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Junyao Shen,Xinyi Gao,Zhen Liu,Ling Zhao,Zhenhao Xi,Weikang Yuan
A deep insight into the reaction mechanism is essential to control the polymerization process with the desired macromolecular structure for high-performance thermotropic liquid crystalline polymer. In this work, density functional theory (DFT) was used to investigate the catalytic polymerization mechanism for the synthesis of thermotropic liquid crystalline polymer catalyzed by zinc(II) carboxylate. The polymerization of 4-acetoxybenzoic acid was studied as a typical reaction. Based on DFT calculations, the rate-limiting step is located in the transesterification between phenol and anhydride acid. The energetically favored pathway was found with the free energy barrier of 51.84 kcal/mol in the presence of zinc acetate, which is significantly lower than the energy barrier without a catalyst. In addition, the effects of the carboxylate group of zinc(II) carboxylate on the catalytic efficiency were revealed by DFT calculations and experiments. Compared with zinc acetate, zinc pivalate has a higher catalytic activity with the rate constant of 1.69 × 10 -2 min −1 ∙M −1 fitted with a second-order reaction model. The HOMO-LUMO gap of zinc pivalate was the smallest among the chosen catalyst, indicating that the chemical activity was strengthened by the methyl substituted. Furthermore, due to the enhanced orbital interactions and the decreased distortion energy in the transition state using zinc pivalate, the energy barrier of the rate-limiting step decreased to 51.36 kcal/mol. These results provide valuable guidance for modeling the catalytic mechanism in aromatic polyester systems.
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高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2023
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IF 10.9
Hainan Wei,Fanming Meng,Han Zhang,Wenqing Yu,Jialong Li,Sheng Yao
Constructing new photocatalysts for the photocatalytic reduction of CO 2 and efficient degradation of Levofloxacin is of great importance to renewable energy. Here, S-scheme Bi 2 MoO 6- x /MoS 2 heterojunction nanospheres containing abundant surface defects (oxygen vacancies) were designed and successfully synthesized to enhance CO 2 photoreduction activity in the absence of other sacrificial agents, co-catalysts or photosensitisers. At the same time, it can efficiently degrade organic pollutants (Levofloxacin). This heterogeneous structure with surface defects provides an abundance of reactive sites, accelerates charge separation and improves oxidation capacity. The improved Bi 2 MoO 6- x /MoS 2 heterogeneous nanospheres show excellent performance under simulated solar light, with the selectivity and yield of 92.45% and 29.01 µmol h −1 , respectively, for the generation of CO. Under visible light, the degradation efficiency of levofloxacin hydrochloride (LVX) reached 96.3% within 25 min and remained as high as 95% after three cycles. This work provides a new idea for the design of new S-scheme photocatalysts and an important reference for the preparation of photocatalysts for the efficient photocatalytic reduction of CO 2 and the efficient degradation of organic pollutants at the same time.
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JOURNAL OF MOLECULAR STRUCTURE
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2017
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IF 1.753
Hu Wang,Xia Zhang,Yu Zhao,Dongmei Zhang,Fan Jin,Yuhua Fan
Three new N 2 O 4 -donor bis-Schiff base Co(II) complexes, Co(C 36 H 34 N 2 O 8 )·2CH 3 OH ( 1 ), Co(C 28 H 34 N 2 O 8 S 2 )·H 2 O ( 2 ) and Co(C 40 H 36 N 4 O 8 )·3CH 3 OH ( 3 ) with distorted octahedral six-coordinate Co(II) centers were synthesized and determined by single crystal X-ray analysis. The X-ray crystallography shows that the metal atoms of three complexes are all six-coordinate with two nitrogen atoms from C N groups, two oxygen atoms from ether groups and two carboxylic oxygen atoms in the mono-ligand, forming a distorted octahedral geometry. Theoretical studies of the three complexes were carried out by density functional theory (DFT) Becke's three-parameter hybrid (B3LYP) method employing the 6-31G basis set. The DFT studies indicate that the calculation is in accordance with the experimental results. Moreover, inhibition of jack bean urease by Co(II) complexes 1–3 have also been investigated. At the same time, a docking analysis using a DOCK program was conducted to determine the probable binding mode by inserting the complexes into the active site of jack bean urease. The experimental values and docking simulation exhibited that the complex 3 showed strong inhibitory activity (IC 50 = 16.43 ± 2.35 μM) and the structure-activity relationships were further discussed.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Pengyang Bian,Qinqin Shao
A silicate-hydrothermal carbon composite material (GHC) was prepared by a one-step hydrothermal method using Canadian horseweed as raw material and cheap sodium silicate and magnesium sulfate as modification reagents for the adsorption of copper (Cu 2+ ), zinc (Zn 2+ ), and tetracycline (TC) in water. The results showed that maximum capacities of the adsorption of Cu 2+ , Zn 2+ , and TC by GHC are 211.92 mg·g −1 , 224.96 mg·g −1 , and 358.58 mg·g −1 . TC can provide certain active sites for GHC to adsorb Cu 2+ or Zn 2+ in a binary system. When the concentration of Cu 2+ or Zn 2+ is low, i.e., <30 mg·L −1 , it will promote GHC’s ability to adsorb TC. When the concentration of Cu 2+ or Zn 2+ is greater than 30 mg·L −1 , the adsorption capacity of GHC to TC began to decrease. This may be related to the presence of too many complexes on the surface of GHC. Too many complexes will block the pores on the surface of GHC and reduce the effective adsorption sites of GHC. The different mechanisms for the adsorption of Cu 2+ and Zn 2+ are different from the adsorption of TC. In this study, 2D-COS and DFT calculations are used to explore these mechanisms. The results show that C O, C O, and C C are involved in the adsorption of Cu 2+ , Zn 2+ , and TC, and C O and C O have stronger capacities than C C for Cu 2+ , Zn 2+ , and TC. GHC has stable adsorption properties for Cu 2+ , Zn 2+ , and TC in different water samples, and has good regeneration performance. Thus, GHC is an economical and efficient adsorbent with good application potential.
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APPLIED SURFACE SCIENCE
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2020
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IF 6.182
Zulfiqar Ali,Yang-wen Wu,Yue Wu,Zulqarnain Arain,Ming-xin Xu,Qiang Lu,Heping Ma,Huan-yu Zhao
Lead (Pb) species are inescapable constituents of the flue gas from coal-fired power plants and other thermal devices, which can cause impeding effects on the selective catalytic reduction (SCR) reactions. Here, the poisoning effects of Pb on the V 2 O 5 -MoO 3 /TiO 2 type SCR catalyst were examined. The poisoned catalysts were prepared by the solid diffusion and incipient wetness impregnation (IWI) methods. The catalytic activity tests indicated that the Pb-doped catalyst prepared by the IWI method suffered a considerable drop in catalytic activity, while a slender influence was observed on the Pb-loaded catalysts prepared by solid diffusion method. Comprehensive characterizations and density functional theory (DFT) calculations were performed on the fresh and poisoned catalysts prepared by the IWI method to unveil the deactivation mechanism. The results showed that Pb species covered the active sites (V species) on the catalyst surface, resulted in the decrease in chemisorbed oxygen, hence reducing the surface acidities. The decrease in reducibility of the catalyst was an important factor for poisoning of the catalyst. Moreover, Pb species reacted with MoO 3 to form PbMoO 4 which agglomerated on the catalyst surface to further deactivate the catalyst.
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FUEL
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2024
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IF 6.7
Faraz Ahmad,Yueli Wen,Muhammad Zeeshan,Bin Wang,Awais Ashraf,Bai Hui,Zheng Cui,Chengda Li,Samia Kausar,Wei Huang
The balance of acid-base property is crucial for the catalytic performance of Side-Chain Alkylation of Toluene with Methanol (SATM). In this work, Na 3 PO 4 modified NaX catalysts with suitable middle base strength and feasible acid-base center distance were prepared by direct solvent-evaporation and exhibited the best styrene selectivity of 45.4 % and the total yield of side chain alkylation products of 71.7 %, respectively at methanol conversion up to 99.9 % in NaX-P (0.075) . Notably, the selectivity exhibits surprising stability in the evaluated 15 days, which might owe to the uniform dispersion of active species and constant acid base property. Combined the comprehensive characterizations of solid-state NMR, FTIR, SEM, and XPS, etc., with Density Functional Theory (DFT) calculation results, it is revealed that O-1264 are affected mostly by loading Na + or both of Na + and PO 4 3- , which exhibits the least adsorption energy and the highest electronic cloud density in the four kinds of oxygen atoms according to the calculated Bader charge. Therefore, the structure S4 (O-1264) was considered to be the most stable and meet the basicity requirements for SATM.
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
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2024
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IF 1.5
Liang Lili,Cheng Qian,Yang Zhou,Lin Xiaoyan,Chen Yan,Luo Xuegang
The extraction of uranium from strong acidic radioactive wastewater is vital and challenging to sustainable development of nuclear energy. In order to improve the selective uranium adsorption, a phytic acid decorated multiple hydorgel network (MA-U-PA/GG-CS-Ca) was constructed by incorporating phytic acid modified covalent organic polymers to gellan gum and chitosan hydrogel by supramolecular self-assembly. The results indicated that the selectivity ratio (SU) of MA-U-PA/GG-CS-Ca for uranium adsorption increased from 28 to 72%. The adjacent –P = O groups within the phytic acid molecule reduces the free energy of the coordination reaction with uranium, which is favorable to the uranium adsorption under acidic condition.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Yi Zhang,Gesheng Li,Zunhua Zhang,Yong Huang,Minghao Li,Jian Li,Mengni Zhou
Highly active catalysts suitable for ammonia reforming reactions have been comprehensively investigated by density functional theory (DFT) calculations and experimental tests. Non-precious metal Ni, precious metal Ru and Ru-Ni composite metal are selected as catalytic activity surfaces, and a series of three-dimensional metal-packed catalyst models are constructed parallelly. Then, to elucidate the rate-determining step of reforming reaction, in-depth analysis of microscopic reaction mechanisms for amino groups (including H and NH x , x =0–3) adsorption, dissociation, recombination and desorption are carried out by simulation parameters and experimental data. The results indicate that NH 3 exhibits highly stable adsorption configurations (Bridge site) on both Ni, Ru-based catalyst surfaces , with the adsorption position having a relatively minor effect on adsorption energy . It is worth noting that Ni-based catalyst exhibits better adsorption behaviors towards NH 3 compared to Ru. Whereas, during stepwise dehydrogenation of NH 3 and subsequent N 2 and H 2 recombination and desorption processes, the reaction energy barriers confirm experimental observations of higher activity displayed by Ru-based catalyst in low-temperature range of 400–500 °C. Interestingly, N 2 synthesis behavior of innovative Ru-Ni bimetallic tandem catalyst surface possesses the lowest reaction energy barrier than other models, which is attributed to the adsorption capability of Ni layers and the catalytic activity of Ru atoms. The experimental results also demonstrate that under typical engine exhaust conditions, the H 2 production efficiency of 1 %Ru-3 %Ni/Al 2 O 3 surpasses that of 1 %Ru/Al 2 O 3 by 6.2 %, showcasing exceptional stability.
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高影响因子
IONICS
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2024
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IF 2.4
Wang Qiqi,Zhang Jingchun,Zhang Yilin,Song Shengjiao,Wang Guowei,Zhuang Linghua,Chen Xiaojun
In this paper, functional ether-based ionic liquids with bromide and dicyanamide anions were prepared and characterized. The introduction of ether group into imidazolium cation decreased the relative viscosity of ionic liquids, while increased density and electrical conductivity values of ionic liquids. The refractive index, density, thermal stability, electrical conductivity, and ESW values of ionic liquids decreased with the increase of alkoxyalkyl chain length from methoxyethyl to methoxypropyl, while the relative viscosity of ionic liquid increased from the methoxyethyl to the methoxypropyl group. The refractive index, relative viscosity, density, and thermal stability of bromide ionic liquids were higher than those of dicyanamide ionic liquids, while the electrical conductivity and ESW values of dicyanamide ionic liquids were higher than those of bromide ionic liquids. DFT simulation results demonstrated the introduction of ether group into imidazolium cation increased anion-cation interactions of ionic liquids, resulting as lower HOMO–LUMO ( E gap ), lower interaction energy (Δ E ), and shorter average hydrogen bond length values. The anion-cation interactions among ionic liquids decreased when ether group changed from methoxyethyl to methoxypropyl. The cation–anion interactions of dicyanamide ionic liquids were much stronger than those of bromide ionic liquids. These results will shed light on the design and preparation of functional ionic liquid electrolytes for the renewable energy storage devices.
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JOURNAL OF POWER SOURCES
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2017
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IF 6.395
Jingbo Yang,Hongwei Mi,Shan Luo,Yongliang Li,Peixin Zhang,Libo Deng,Lingna Sun,Xiangzhong Ren
Flexible Li-O 2 batteries have attracted worldwide research interests and been considered to be potential alternatives for the next-generation flexible devices. Nitrogen-doped carbon nanofibers (N-CNFs) prepared by electrospinning are used as flexible substrate and an amorphous TiO 2 layer is coated by atomic layer deposition (ALD) and then decorated with Ru nanoparticles . The Ru/N-CNFs@TiO 2 composite is directly used as a free-standing electrode for Li-O 2 batteries and the electrode delivers a high specific capacity, improved round-trip efficiency and good cycling ability. The superior electrochemical performance can be attributed to the amorphous TiO 2 protecting layer and superior catalytic activity of Ru nanoparticles. Based on density functional theory (DFT) calculations from first principles, the carbon electrode after coating with TiO 2 is more stable during discharge/charge process. The analysis of Li 2 O 2 on three different interfaces (Li 2 O 2 /N-CNFs, Li 2 O 2 /TiO 2 , and Li 2 O 2 /Ru) indicates that the electron transport capacity was higher on Ru and TiO 2 compared with N-CNFs, therefore, Li 2 O 2 could be formed and decomposed more easily on the Ru/N-CNFs@TiO 2 cathode. This work paves a way to develop the free-standing cathode materials for the future development of high-performance flexible energy storage systems .
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ENVIRONMENTAL RESEARCH
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2025
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IF 7.7
Qianqian Ni,Huiping Shao,Yun Zhang,Xin Ke,Wengang Liu
Oxygen vacancies could be induced into the heterojunction structure of BiOI/BiOBr via high-temperature calcination. Light absorption, charge transfer efficiency, photocatalytic activity, and mechanism are all intimately connected to oxygen vacancies. Density-functional theory simulations demonstrate that surface oxygen vacancies adsorb oxygen to active sites, whereas bulk oxygen vacancies activate oxygen adsorbed to the surface to reactive radicals. Meanwhile, the addition of oxygen vacancies efficiently reduces the effects of background ions and pH on tetracycline breakdown in the real aquatic environment. The experimental results are consistent with the DFT calculations. This paper presents a straightforward approach for creating heterojunction surface and bulk-phase oxygen vacancies, as well as an understanding of the many roles that different types of oxygen vacancies play in the photocatalytic degradation process.
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Jiaxin Luo,Yihui Wu,Dawei Xiang,Shixing Wang,Jianqiang Ye,Hongliang Liu,Libo Zhang
Gallium is a strategic metal extensively applied in semiconductors, optoelectronics, and LED manufacturing. However, extracting Ga(III) from aqueous solutions remains challenging due to its typically low concentrations and interference from coexisting metal ions. In this study, a novel cross-linked COF-COF material (DPDA), enriched with nitrogen- and oxygen-containing functional groups, was synthesized and systematically evaluated for its ability to selectively adsorb Ga(III) from complex aqueous systems. DPDA exhibited outstanding adsorption performance under alkaline conditions and showed significantly enhanced Ga(III) uptake compared with its precursor. Kinetic analysis revealed that the adsorption process followed a pseudo-second-order model, indicating chemisorption played a predominant role. Langmuir isotherm fitting further demonstrated a monolayer adsorption pattern, yielding a maximum capacity of 112.4 mg·g −1 at 318 K. DPDA exhibited strong affinity for Ga(III) even in the presence of competing metal ions. In terms of reusability, DPDA maintained more than 67 % of its removal efficiency after 16 successive adsorption-desorption cycles, highlighting its structural robustness and practical applicability. Mechanistic analysis indicated that Ga(III) uptake by DPDA proceeds through a combination of coordination chemisorption, ion-exchange processes, and electrostatic interactions. DFT calculations identified stable adsorption configurations and quantified adsorption energies, confirming the synergistic contribution of -OH and -NH groups to Ga(III) binding. This work provides deeper insight into Ga(III) adsorption mechanisms and proposes a practical approach for its selective recovery from complex aqueous environments.
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