PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2016
·Vol. 18
·期 29
·19731-19737
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IF 4.449
Yingna Cui,Jingmei Yin,Changping Li,Shenmin Li,Ailing Wang,Guang Yang,Yingping Jia
The compositions and structures of amine-based functionalized protic ionic liquids (PILs), namely N,N-dimethyl(cyanoethyl)ammonium propionate (DMCEAP) and N,N-dimethyl(hydroxyethyl)ammonium propionate (DMEOAP) have been investigated systematically by IR and 1H NMR spectroscopy and density functional theory (DFT) calculations. Analysis of the IR spectra suggests that both DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase, the former one mainly existing in the state of precursor molecules, and the latter mainly as ion-pairs. The ratio of precursor molecules to ion-pairs in the liquid phase depends on the types of precursors, especially the functional groups of cations. 1H NMR spectra indicate that there is a dynamic equilibrium between the neutral and ionized species, probably due to the formation of some intermediates in the PILs. The DFT calculations have been carried out to reveal the conformation, and obtain the corresponding IR and 1H NMR spectra of the neutral and ionized species, so that the theoretical support to the experimental results can be provided. The present study will help understand the properties of PILs and provide guidance for further applications of PILs.
研究领域:
物理化学
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离子液体化学
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光谱学
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理论化学
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分析化学
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材料化学
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ACS Applied Materials & Interfaces
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2024
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IF 8.3
Ruoyu Wei,Mansheng Liao,Lidan Sun,Qingfeng Zhang,Hong Zhang,Lei Zhang,Zhongxin Song
Developing highly efficient and low-cost bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting poses significant challenges. In this study, a novel bifunctional electrocatalyst, Irn-CoMoPOx, was achieved via incorporating low-loading Ir single atoms and clusters with the high-valence Mo6+ modified CoPOx nanosheets. The Irn-CoMoPOx catalyst demonstrates remarkable low overpotentials of 222 mV and 36 mV for the OER and HER, respectively, in delivering a current density of 10 mA cm–2. When employed as both the anode and cathode catalyst in overall water splitting, the Irn-CoMoPOx∥Irn-CoMoPOx configuration exhibits a superior cell voltage of 1.53 V, outperforming the benchmark Pt/C∥IrO2 electrolytic cell (1.60 V) for achieving the current density of 10 mA cm–2. Benefiting from the high-valence of Mo species, the metal–support interaction of Irn-CoMoPOx was greatly strengthened, resulting in an order of magnitude increase in the mass activity of Ir for the HER. The high valence of non-noble metals plays a crucial role in tuning the local electronic configurations and optimizing the adsorption energies of the intermediates, which synergistically improves the overall performance of Ir in water splitting. The study provides valuable insights for future research in the utilization of Ir-based bifunctional catalysts for overall water electrocatalysis applications.
研究领域:
材料科学
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电化学
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催化反应
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2016
·
IF 3.205
Bao-Xia Dong,Hui Tian,Yi-Chen Wu,Fan-Yan Bu,Wen-Long Liu,Yun-Lei Teng,Guo-Wang Diao
Liquid ammonia electrolysis is conducted out at ambient temperature using different ammonium salt electrolytes with and without the reference electrode. It is determined that electrolytes containing NH 4 + increase the current density and reduce the solution resistance. Moreover, ammonium salts of NH 4 Br, NH 4 NO 3 and NH 4 Cl preserve >80% current efficiency and a 0.6–0.8 mL min −1 average rate of H 2 generation during chronopotentiometry tests at 120 mA cm −2 for 3 h. A minimum electrolysis voltage ( E min ) of ca . 1.2 V is required for the NH 4 Cl electrolyte when using Pt-foil as the anode and cathode . To decrease the overpotential of the anode reaction, five types of electrocatalysts were prepared and characterized: Pt-black, Rh, Pt–Ir, Rh–Pt and Ph–Pt–Ir alloys. Trimetallic Rh–Pt–Ir and bimetallic Pt–Ir, Rh–Pt (1:1) alloy electrodes exhibit a combined benefit of better activity and minimized deactivation. The ternary Rh–Pt–Ir alloy anode shows the best electrocatalytic activity with the lowest E min of ca . 0.47 V and highest current density of 46.9 mA cm −2 at 2.0 V. In comparison with the Pt-foil anode, the E min is reduced by two-thirds, and the current density is increased two-fold.
研究领域:
化学工程
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能源科学
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INFRARED PHYSICS & TECHNOLOGY
·
2018
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IF 1.851
Honghan Bu,Guoyue Xu,Chuyang Liu,Tengchao Guo,Shujuan Tan
The green BCG/MgCl 2 /PEG-g-CDA powders were synthesized at different temperatures via liquid-phase reaction method. The microstructures of the synthesized powders were analyzed and characterized by FT-IR, XRD and ChemDraw software. The effects of synthesized temperatures on infrared emissivity properties of the powders in the wavelength range 3–5 μm were investigated systematically. It is found that the powders heated at 100 °C exhibit the optimum crystallinity at room temperature and thus show the largest variation (0.4) in infrared emissivity with the test temperature varying from 50 °C to 65 °C. Furthermore, the mechanisms for the self-regulated infrared emissivity properties are also explored thoroughly. The variation of infrared emissivity with temperature is ascribed to the changes in resistivity, which is induced by the transformation of PEG-g-CDA between crystalline and amorphous as well as the molecular structure transition of BCG between quinone and lactone. Our results suggest that BCG/MgCl 2 /PEG-g-CDA powders are potential candidates for intelligent infrared camouflage.
研究领域:
材料科学
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光学
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化学工程
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JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2023
·
IF 10.9
Binyu Zhang,Weiwei Li,Kexi Zhang,Jingtao Gao,Yang Cao,Yuqian Cheng,Delun Chen,Qiang Wu,Lei Ding,Jinchun Tu,Xiaolin Zhang,Chenghua Sun
Strain engineering of two-dimensional (2D) material interfaces represents a powerful strategy for enhancing the electrocatalytic activity of water splitting. However, maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge. The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets (NSs) derived from metal organic frameworks (Ir@NiO/C BDC ), which displays a high activity and stability under all pH conditions, and even a change of only 1% in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions. Through combined experimental and computational studies, we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/C BDC catalyst, arising from its increased Ir and Ni vacancy formation energies, and hence suppressing its leaching. Moreover, strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by optimizing its electronic structure and coordination environment. This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable electrocatalysts.
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ANALYST
·
2023
·Vol. 148
·期 22
·5650-5657
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IF 4.2
Wenjing Gao,Ying Han,Liangqiang Chen,Xue Tan,Jieyou Liu,Jinghang Xie,Bin Li,Huilin Zhao,Shaoning Yu,Huabin Tu,Bin Feng,Fan Yang
Microbes are usually present as a specific microbiota, and their classification remains a challenge. MALDI-TOF MS is particularly successful in library-based microbial identification at the species level as it analyzes the molecular weight of peptides and ribosomal proteins. FT-IR allows more accurate classification of bacteria at the subspecies level due to the high sensitivity, specificity and repeatability of FT-IR signals from bacteria, which is not achievable with MALDI-TOF MS. Previous studies have shown that more accurate identification results can be obtained by the fusion of FT-IR and MALDI-TOF MS spectral data. Here, we constructed 20 groups of model microbiota samples and used FT-IR, MALDI-TOF MS, and their fusion data to classify them. Hierarchical clustering analysis (HCA) showed that the classification accuracy of FT-IR, MALDI-TOF MS, and the fusion data was 85%, 90%, and 100%, respectively. These results indicate that both FT-IR and MALDI-TOF MS can effectively classify specific microbiota, and the fusion of their spectral data could improve the classification accuracy. The FT-IR and MALDI-TOF MS data fusion strategy may be a promising technology for specific microbiota classification.
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ACS Sustainable Chemistry & Engineering
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2023
·
IF 8.4
Shuang Chen,Yue Wang,Yifan Huang,Yifan Zhang,Pengyang Deng
A novel photosensitizer hybrid film (Ir(cumr)2(dabpy)+@NWF-g-MAH) has been designed and synthesized by anchoring a coumarin–Ir(III) complex on a polymer substrate. Photocatalytic tests show that Ir(cumr)2(dabpy)+@NWF-g-MAH displays a long lifetime of over 650 h under visible-light irradiation. The hydrogen evolution efficiency of Ir(cumr)2(dabpy)+@NWF-g-MAH is nearly 25 times higher than that of [Ir(ppy)2(dabpy)]+@NWF-g-MAH in 100 h, and optimizing the average concentration of Ir(cumr)2(dabpy)+@NWF-g-MAH in the hydrogen evolution system improves the hydrogen evolution amount to 12 790 μmol m–2. This photocatalytic system achieves the best synergy of hydrogen evolution efficiency and lifetime so far. The high performance is derived from the sterically bulky substrate effectively inhibiting the photodegradation of the photosensitizer and the coumarin group with strong visible-light absorption in the visible region. This work provides a novel direction for developing a durable and efficient Ir(III) complex for photocatalytic application.
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Small
·
2023
·Vol. 19
·期 52
·2305343
·
IF 13.3
Yingxiu Zhao,Qiyan Sun,Xinyuan Zhou,Zhiyao Duan,Chuanfang Zhang,Guang-Rui Xu,Dianxing Ju,Lei Wang
Design high-loading with superior activity and high atomic efficiency has consistently been a new frontier of heterogeneous catalysis while challenging in synthetic technology. In this work, a universal solid-state strategy is proposed for large scalable production of high-loading Ir clusters on porous hollow carbon nanobowls (Ir CSs/PHCNBs). The strong electronic interaction between metallic Ir cluster and C on PHCNBs leads to electron redistribution, which significantly improves the electron transfer rate on the interface. The obtained Ir CSs/PHCNBs only require overpotentials of 35, 34, and 37 mV for the hydrogen evolution reaction (HER) with stable outputting of 10 mA cm −2 under acidic, alkaline, and neutral conditions, respectively, which exceeds the state-of-the-art HER electrocatalysts. Meanwhile, the Tafel slopes of Ir CSs/PHCNBs for the HER process are 23.07, 48.76, and 28.95 mV dec −1 , greatly lower than that of PHCNBs (152.73, 227.96, and 140.29 mV dec −1 ) and commercial Pt/C (20%) (36.33, 66.10, and 36.61 mV dec −1 ). These results provide a new strategy for the universal synthesis of clusters catalysts and insight into understanding the interface effects between clusters and carbon substrate, facilitating the industrial application of hydrogen production.
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DYES AND PIGMENTS
·
2022
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IF 5.122
Peiyu Tan,Feifei Lu,Yuge Han
A dual-layer structure combining the properties of two polymers is demonstrated to be efficient in strengthening the mid-to-far infrared modulation. Prior to the assembly of bilayer devices, the infrared adjustment capability of single-layer devices poly(3,4-ethylenedioxythiophene) ( PEDOT )、poly(pyrrole) ( PPY ) and poly(aniline) ( PANI ) with different polymerization charges is scrutinized. The results exhibit that the optimal polymerization charge affording the highest reflectance variation is inconsistent between the mid-wavelength and long-wavelength bands in PEDOT and PPY devices. However, through the arrangement of deposition sequence and relative thickness of PEDOT and PPY coatings, a device with the reflectance contrast of 0.662 in the mid-wavelength and 0.281 in the long-wavelength bands was obtained utilizing a bilayer film PEDOT-0.2C/PPY-0.3C . Further FTIR and UV–Vis spectra show that the bilayer films are successfully formed and both polymers play a role in the electrochemical process . Different morphologies of bilayer films with reverse positions observed by SEM images account for the correlation between the infrared regulation performance and deposition sequence.
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DALTON TRANSACTIONS
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2023
·
IF 4
Yuanlei Huang,Mengdi Lv,Binglian Guo,Guojing Hu,Yong Qian,Zhi Su,Xuling Xue,Hong-Ke Liu
Breast cancer (BC) is one of the most common malignant tumors and often accompanied by inflammatory processes. Inflammation is an essential component of the tumor microenvironment, which might influence tumor proliferation and metastasis. Herein, three metal–arene complexes MA-bip-Ru, MA-bpy-Ir, and MA-bpy-Ru were prepared by tethering the non-steroidal anti-inflammatory drug meclofenamic acid (MA). Among them, MA-bip-Ru and MA-bpy-Ir showed lower cytotoxicity towards cancer cells, but MA-bpy-Ru showed significantly high selectivity and cytotoxicity towards MCF-7 cells through the autophagic pathway and exhibited no toxicity against normal HLF cells, showing potential for selective treatment of tumor cells. MA-bpy-Ru could also effectively destroy the 3D multicellular tumor spheroids, demonstrating its potential for clinical application. Besides, MA-bip-Ru, MA-bpy-Ir, and MA-bpy-Ru exhibited anti-inflammatory properties superior to MA, notably downregulating the expression of cyclooxygenase-2 (COX-2) and inhibiting the secretion of prostaglandin E2 in vitro. These findings demonstrated that MA-bpy-Ru was capable of intervening in inflammatory processes and showed the potential of MA-bpy-Ru to act as a selective anticancer agent, thus presenting a new mechanism of action for metal–arene complexes.
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ACS Applied Nano Materials
·
2021
·
IF 5.097
Hongbo Yu,Chunzheng Wu,Shiwei Wang,Tong Li,Hongfeng Yin
Modification of active metals with metal oxide modifiers has attracted considerable attention in heterogeneous catalysis due to their synergistic effect. However, a controllable synthesis of highly reactive and stable metal–metal oxide hybrid nanocatalysts is difficult. To solve this problem, presynthesized IrM (M = Fe, Co, and Ni) bimetallic nanoparticles were initially confined in the mesopores of SBA-15 and were then in situ transformed to Ir-MOx hybrids. The obtained Ir-MOx/SBA-15 nanocatalysts show superior activity and selectivity in the hydrogenation of substituted nitroaromatics to corresponding aromatic amines compared to Ir/SBA-15. Among these Ir-based catalysts, Ir-FeOx/SBA-15 exhibits the highest activity and selectivity and has a wider substrate scope due to the interaction between Ir and FeOx. Therefore, our research provides a way to design reactive and stable hydrogenation catalysts.
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Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 48
·25687-25695
·
IF 11.301
Lei Li,Guilin Li,Yaping Zhang,Wenjun Ouyang,Huiwen Zhang,Feifei Dong,Xuehui Gao,Zhan Lin
Water splitting by electrolysis is a promising technology that can address rising energy demands and environmental pollution. However, the oxygen evolution reaction (OER), as one half-cell reaction of water splitting, always suffers from slow kinetics and a large overpotential due to the four proton-coupled electron transfer process, and dominates the overall process efficiency. IrO2 is a promising and widely used catalyst for the OER in commercial applications. Herein, we obtained low-crystalline nano-IrO2 particles confined in an amorphous Ir-based MOF (IrO2@Ir-MOF) through a simple solvothermal reaction, in which ultrafine IrO2 particles are uniformly distributed in the Ir-MOF skeleton. The fabricated IrO2@Ir-MOF-ppy electrode exhibits excellent OER activity with an overpotential of 207 mV, to achieve a current density of 10 mA cm−2 in 1 M KOH solution, outperforming most previously reported OER catalysts. The IrO2@Ir-MOF‖IrO2@Ir-MOF couple exhibits promising activity and stability for the overall water splitting reaction in 1 M KOH (1.53 V).
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