Nature Synthesis
·
2023
·Vol. 2
·期 5
·423-429
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IF 0
Yue Xu-Hui,Chen Wei-Xing,Yang Tao,Muñoz-Castro Alvaro,Frenking Gernot,Sun Zhong-Ming
Traditionally, a metallocene complex comprises a metal centre sandwiched between two aromatic organic ligands and such complexes have been extensively investigated. Carbon-free analogues of metallocene with homoleptic As 5 or Sb 5 ligands, however, have remained experimentally elusive, especially analogues of higher nuclearity. Here we report the synthesis and characterization of sandwich-type clusters [Pn@M 12 Pn 10 (Pn 5 ) 2 ] 4–/5– (Pn = As, Sb; M = Co, Fe), where the endohedral icosahedral cluster [Pn@M 12 ] can be regarded as a spherical-like three-dimensional coordination centre surrounded by a Pn 10 ring and two Pn 5 pentagonal caps. Quantum chemical calculations reveal that the [Pn@M 12 ] has orbitals that mimic 1S, 1P and 1D electronic shells, which can interact with the outer (Pn 5 ) 2 ring layer. These interactions occur because the frontier orbitals are dominated by the ( n − 1) d block orbitals of the metal atoms. The π 1 -As 5 orbitals interact with 1S and part of the 1P shell of the central core, while the π 2 - and π 3 -As 5 orbitals interact with the symmetry-allowed part of the 1P and 1D shells. The characteristics of this orbital interaction are analogous to those of mononuclear metallocenes.
研究领域:
无机化学
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材料科学
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理论化学
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DOI
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
·
IF 6.3
Qiufan Sun,Yuxiang Zhu,Yan Wang,Zhengtao Jia,Xiang Zhong,Jianfeng Yao
Three isostructural MIL-68(M)-NH 2 frameworks (M = In, Fe, or Al) featuring different metal centers were synthesized to investigate their photocatalytic activities for nitrogen fixation. The influence of the metal oxo clusters on the crystalline structures, morphologies, and optical characteristics was examined. MIL-68(In)-NH 2 (MNI) with one-dimensional microrod structures has a larger surface area than bulk MIL-68(Fe)-NH 2 (MNF) and spherical MIL-68(Al)-NH 2 (MNA), and achieves an ammonia generation rate (140.34 μmol g cat −1 h −1 ) ca . 3.4 and 1.6 times higher than those of MNF (37.25 μmol g cat −1 h −1 ) and MNA (87.5 μmol g cat −1 h −1 ), respectively. The superior performance can be attributed to its high crystallinity, strong coordination between the In−oxo clusters and ligands, and microrod morphology, which enhance electron transfer, improve mass transport, and extend visible light absorption. Moreover, MNI shows greater stability in ethanol aqueous solution than other sacrificial reagents, such as methanol, potassium sulfite, and triethanolamine. While slight surface corrosion of the microrods occurs in methanol and potassium sulfite solutions, complete collapse is observed in triethanolamine.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Nanomaterials
·
2018
·
IF 2.207
Ping Niu,Dunqing Wang,Aili Wang,Yuhua Liang,Xinfang Wang
Bifunctional films of Keggin-type polyoxometalates H3PW12O40 (PW12), H4SiW12O40 (SiW12), H3PMo12O40 (PMo12), and TiO2 were successfully built on Fe3O4@SiO2 microspheres using a layer-by-layer method. The characterization by field emission scan electronic microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX) shows that TiO2 nanoparticles and polyoxometalate (POM) anions are successfully assembled. The photodegradation of methyl orange (MO) was used to test the photocatalytic efficiency of magnetic catalysts under UV irradiation. For MO decomposition, multilayer films that combine PW12 and SiW12 with TiO2 show high efficiency, which can be attributed to the synergistic effect between POMs and TiO2. The degradation of the model contaminant was also systematically checked under different conditions such as bilayer number deposited on magnetic microspheres, catalyst concentration, inorganic oxidants, and salts. The oxidation process of MO follows an apparent first-order reaction. Furthermore, the composite catalysts deposited on Fe3O4@SiO2 magnetic microspheres can be conveniently, quickly, and efficiently separated by an external magnet from a solution.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 41
·15451-15457
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IF 8.067
Xi-Zhu Zhang,Wen-Jing Zhu,Zhong-Xi Yang,Yi Feng,Lin-Lin Fan,Guang-Gang Gao,Hong Liu
The sensitive and selective detection of ethylenediamine (EDA) has great significance due to its threat to environment and human health. Herein, a rationally designed polyoxometalate–viologen complex (1) has been demonstrated, in which the viologen molecules are hydrogen bonded to Dawson-type polyoxoanions. When complex 1 is in the atmosphere of EDA, the chromic intensity or Raman signals present proportional response to EDA concentrations. In particular, a very low detection limit of 0.1 ppb can be obtained for 1 based on its Raman signal output, which is the most sensitive complex than the reported EDA sensors. Also, high selectivity is observed for 1 when other amine molecules coexist as interfering compounds. According to the structural analysis and comparative experimental results, the highly sensitive and selective chromic or Raman response can be ascribed to the existence of viologen in the crystal lattice, which can not only accept electrons from EDA but also effectively accelerate the electron transfer to polyoxometalate. This work affords a novel concept for the design of highly sensitive and dual response polyoxometalate-based sensors by virtue of viologen-boosting electron transfer.
研究领域:
材料科学
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环境科学
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化学传感器
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Zhengyu Wei,Tianyi Ding,Caihe Bai,Ruisheng Zhang,Sen Yang,Wei Wei
Non-oxidative intercalation of graphite avoids damage to graphene lattices and is a suitable method to produce high-quality graphene. However, the yield of exfoliated graphene is low in this process due to the poor delamination efficiency of guest species. In this study, a Brønsted acid intercalation protocol is developed involving polyoxometalate (POM) clusters (H 6 P 2 W 18 O 62 ) as guests and intercalation of graphite is realized at the sub-nanometer scale. Theoretical simulation based on DFT elucidates the stepwise intercalation mechanism of Brønsted acid molecules and clusters. Unlike common molecules/ionic guests, intercalation of POM clusters induces large expansion and extensive donor–acceptor interactions among graphite interlayers. This significantly weakens the van der Waals forces and promotes exfoliation efficiency of graphene layers. The exfoliated graphene possesses outstanding features of large lateral size, thin thickness, and high purity, and shows excellent performance as the anode for high power sodium-ion batteries. This work proffers a new pathway toward non-oxidative intercalation of graphite for large-scale production of graphene.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2016
·Vol. 22
·期 46
·16613-16620
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IF 5.771
Pengyuan Wang,Jia Liu,Chuanfang Liu,Bin Zheng,Xiaoqin Zou,Mingjun Jia,Guangshan Zhu
Graphical Clusters in voids : Very small metal clusters (Au, Pd, Pt) with sizes around 1.2 nm can be facilely encapsulated within sub-nano-sized cavities of zeolitic imidazolate framework 8 (ZIF-8) through electrochemical synthesis. The confined clusters possess clean surfaces and excellent stabilities, as well as superior catalytic properties in CO oxidation including high turnover rates and good selectivity toward reactants based on narrow pore windows (see figure). It is very interesting and also a big challenge to encapsulate metal clusters within microporous solids to expand their application diversity. For this target, herein, we present an electrochemical synthesis strategy for the encapsulation of noble metals (Au, Pd, Pt) within ZIF-8 cavities. In this method, metal precursors of AuCl 4 2− , PtCl 6 2− , and PdCl 4 2− are introduced into ZIF-8 crystals during the concurrent crystallization of ZIF-8 at the anode. As a consequence, very small metal clusters with sizes around 1.2 nm are obtained within ZIF-8 crystals after hydrogen reduction; these clusters exhibit high thermal stability, as evident from the good maintenance of their original sizes after a high-temperature test. The catalytic properties of the encapsulated metal clusters within ZIF-8 are evaluated for CO oxidations. Because of the small pore window of ZIF-8 (0.34 nm) and the confinement effect of small pores, about 80 % of the metal clusters (fractions of 0.74, 0.77, and 0.75 for Au, Pt, and Pd in ZIF-8, respectively) retain their catalytic activity after exposure to the organosulfur poison thiophene (0.46 nm), which is in contrast to their counterparts (fractions of 0.22, 0.25, and 0.20 for Au, Pt, and Pd on the SiO 2 support). The excellent performances of metal clusters encapsulated within ZIF-8 crystals give new opportunities for catalytic reactions.
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yongqi Yang,Jiaqi Li,Xinyao Li,Lin Guan,Zijian Gao,Lijie Duan,Fei Jia,Guanghui Gao
Paper, for writing and printing, is consumed a lot in modern life. However, the production of conventional paper could cause many problems, such as deforestation and environmental pollution. Therefore, it is necessary and urgent to explore novel strategies to solve these problems. In this work, a polyoxometalate-doped gelatin film with high strength, excellent transparency, and fast photochromic properties is designed and prepared. The film can display different colors by using a variety of reagents, exhibiting its potential application as a paper medium. Its rapid photochromic properties allow complex high-resolution images to be displayed by UV light printing. It is found that the mechanical and photochromic properties could be regulated by the introduction of triethylene glycol, and the fading process could be controlled by changing the temperature and humidity. Moreover, it is rewritable, self-repairable, and recyclable, and can also achieve long-term preservation without fading. It is envisioned that the environmentally friendly films with low cost, ease of preparation, and recycling advantages have the potential to be an alternative to conventional paper for writing and printing.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
PubMed
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2024
·Vol. 89
·期 4
·904-914
·
IF 2.5
Lu Qi,Yang Haodong,Chen Zhe,Yao Lei
View large Download slide View large Download slide Close modal In this study, polyoxometalates (POMs) as a core-modifying material was used to fabricate the nanofiltration (NF) membrane on the polyvinylidene fluoride (PVDF) microfiltration membrane substrate via a novel interfacial polymerization (IP) method. The formation mechanism of the POMs-modified composite membrane was proposed. The separation and antifouling properties were further investigated. After cross-linking with POMs through the new IP reaction, the modified composite membrane showed improved hydrophilicity, water flux, and salt rejection. In the humic acid fouling experiment, the POMs-modified membrane exhibited the best antifouling performance, with a flux recovery rate of up to 91.3%. Electrochemical impedance spectroscopy was further used to investigate the antifouling performance of the membranes. Nyquist and Bode plots of the POMs-modified membranes showed no significant change before and after fouling compared to the PVDF membrane substrate, indicating reduced fouling attachment on the modified membrane, which was consistent with the fouling index and flux variation observed during the fouling experiment. Our findings provide a simple and valuable route for fabricating POMs-functionalized NF membranes with desirable separation and antifouling performance. A simple method is proposed to modify POMs onto the NF membrane. The separation and antifouling performance of the POMs-modified membranes improved evidently. After simple cleaning, the flux recovery rate of the POMs-modified membrane reached more than 90%. Improved antifouling performance of the POMs-modified membrane was confirmed by electrochemical impedance spectroscopy analysis.
研究领域:
材料科学
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环境工程
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 90
·48931-48937
·
IF 3.708
Jianhua Qiu,Xuyang Zhou,Qianqian Mo,Fang Liu,Liping Jiang
Polymer brushes have been used as supports for the immobilization of Keggin-type polyoxometalates (POMs) catalysts on poly(vinylidene fluoride) (PVDF) membranes by electrostatic-assembly. The poly(4-vinylpyridine) (P4VP) polymers are effectively grafted from PVDF membranes via surface-initiated atom transfer radical polymerization with activators generated by electron transfer (SI-AGET ATRP), and the P4VP-grafted PVDF membranes are characterized via ATR-FTIR, XPS, SEM, and AFM. Subsequently, the quaternization of the P4VP brushes process creates a membrane with a positive charge. The pendant pyridine and pyridinium groups facilitate the electrostatic assembly of POMs onto the P4VP-grafted membrane, thereby fabricating a well-designed membrane with potential catalytic applications. Therefore, such systems are interesting candidates for the heterogenization of POMs onto polymer-grafted membranes.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2023
·
IF 10.9
Wencheng Fang,Dong Liu,Ying Zhang,Hao Feng,Qiang Li
Photoelectrochemical water splitting using semiconductor materials is one of the most promising methods for converting solar energy into chemical energy. Among the commonly used semiconductors, p-type CuBi 2 O 4 is considered one of the most suitable photocathode materials and can allow a theoretical photocurrent density of about 20 mA·cm −2 for photoelectrochemical water splitting. However, due to severe charge carrier recombination, the obtained photocurrent density is much lower than the theoretical value. Highly efficient photoelectrochemical performance relies on fast charge carrier separation and transport, and prompt reaction kinetics. In this study, we report the development of a polyoxometalate-modified CuBi 2 O 4 /Mg-CuBi 2 O 4 homojunction photocathode to improve both the bulk and interfacial charge carrier transport in the photocathode. For the bulk of the photocathode, the built-in electric field originating from the CuBi 2 O 4 /Mg-CuBi 2 O 4 homojunction promotes the migration of photo-excited electrons on the conduction band from pure CuBi 2 O 4 to Mg-doped CuBi 2 O 4 . Additionally, the electric field facilitates the transfer of holes from the valence band of Mg-doped CuBi 2 O 4 to pure CuBi 2 O 4 . This directional transfer of both photo-excited electrons and holes plays a significant role in promoting separation and suppressing the recombination of the charge carriers. On the surface of the photocathode, the reduced polyoxometalate co-catalyst Ag 6 [P 2 W 18 O 62 ] (AgP 2 W 18 ) was used as a proton sponge to accelerate surface reaction kinetics and suppress carrier recombination. These synergistic effects improved the photo-generated charge carrier transfer and reaction kinetics. As a result, the novel photocathode displayed excellent photoelectrochemical properties, and the photocurrent density was observed to be −0.64 mA·cm −2 at 0.3 V vs. RHE, which is better than that of −0.39 mA·cm −2 for a pure photocathode. Furthermore, the novel photocathode had an applied bias photon-to-current efficiency (ABPE) higher than 0.19% at 0.3 V vs. RHE. In contrast, the pure photocathode had an ABPE of ~0.12% under the same conditions. Additionally, when H 2 O 2 was used as an electron scavenger, the photocurrent density was −3 mA·cm −2 at 0.3 V vs . RHE, which is an improvement of approximately 1.5 times compared to the pure photocathode. Furthermore, the charge separation and charge injection efficiency of the novel photocathode were significantly improved compared with the pure photocathode. The experimental results conclusively indicate that the formation of the CuBi 2 O 4 /Mg-CuBi 2 O 4 homojunction and AgP 2 W 18 modification played a significant role in the improved performance of the CuBi 2 O 4 photocathode. The performance of the novel photocathode was comparable with the results reported in previous studies, demonstrating its promising potential in real applications. Download: Download high-res image (83KB) Download: Download full-size image
研究领域:
材料科学
·
能源转化
·
光催化
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2017
·
IF 3.012
Ailing Han,Yayu Yang,Qiang Zhang,Qingxia Tu,Guozhen Fang,Jifeng Liu,Shuo Wang,Rui Li
The electrochemistry and electrochemiluminescence (ECL) of copper metal cluster were studied in this work. The redox behavior observed was originated from the couples of Cu 8 + /Cu 8 2 + , Cu 8 /Cu 8 2 + , Cu 8 /Cu 8 + at the cluster metal core. ECL light emissions were observed under both annihilation and tripropylamine co-reactant conditions and only one excited state was involved in this ECL process and this excited state was also at the metal core. Theoretical investigation found that this excitation corresponds to an electron transfer from the metal core to the ligands. And the energy released from excited sate was approximate to the LUMO → HOMO gap energy of the cluster.
研究领域:
分析化学
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电化学
·
光化学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Huawei Yang,Bin Jiang,Yongli Sun,Luhong Zhang,Zhaohe Huang,Zhaoning Sun,Na Yang
In this work, the simple preparation of novel polymer supported polyoxometallates (POMs) catalysts has been reported. Soluble task-specific cross-linked poly (ionic liquid) (PIL) was prepared with N , N -dimethyl-dodecyl-(4-vinylbenzyl) ammonium chloride and divinylbenzene as co-monomers. The as-prepared cationic PILs were assembled with different commercial POMs to form the interlinked mesoporous catalysts, and the formation mechanism was provided. The catalytic oxidation activities of the catalysts were closely related to the formation pathway of their corresponding peroxide active species. The catalyst with H 2 W 12 O 42 10− as counterion, which exhibited the best activity in the oxidation of benzothiophene (BT) and dibenzothiophene (DBT) to sulfones in model oil with hydrogen peroxide (H 2 O 2 , 30 wt%) as oxidant, was characterized by different techniques and systematically studied for its sulfur removal performance. As for the oxidative desulfurization of a real diesel, it was observed that almost all of the original sulfur compounds could be completely converted, and the catalyst could be reused for at least eight cycles without noticeable changes in both catalytic activity and chemical structure. In the end, a catalytic mechanism was put forward with the assistant of Raman analysis.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）