PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 28
·16973-16978
·
IF 3.945
Fengyi Zhou,Ruifen Shi,Yingxiong Wang,Zhimin Xue,Baolong Zhang,Tiancheng Mu
Acidic deep eutectic solvents (ADESs) have been utilized in various applications. Clearly, it is crucial to obtain acidity information that could reveal the relationship with performance. However, appropriate methods for measuring acidity are limited. Herein, we developed two promising approaches (without additional solvents) to identify and characterize both Lewis and Brønsted acidities by applying acetonitrile as an infrared probe and trimethylphosphine oxide (TMPO) as a nuclear magnetic resonance (NMR) probe. The acetonitrile IR approach is suitable for measuring the acidity of Lewis ADESs by monitoring the peak of ν(CN) around 2300 cm−1, and the 31P-TMPO NMR approach could identify and scale both Lewis and Brønsted acidities precisely. Moreover, a perfect linear relationship between the IR shift of ν(CN) and the effective charge density of metal cations was established, which provides a better understanding of Lewis acidity. In short, this study not only offers two efficient acidity measurement methods but also provides a molecular basis for optimizing the performance of ADESs in applications.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS
·
2021
·
IF 2.348
Ruilin He,Yingnan Yang,Pan Yang,Xiaochong Zhao,Jing Zhu,Ruizhu Yang,Qingsong Huang,Lijun Yang
It is essential to develop high-performance hydrogen evolution reaction catalysts. Reducing the amount of precious metals is an effective approach to replace Pt-based catalyst. Here, an electrocatalyst of metallic iridium anchored on mesoporous carbon nanofibers (Ir- m CNFs) is reported. After optimized the nanostructure (pore-forming agent content) of Ir- m CNFs, at the current density of 10 mA cm −2 , the overpotential reaches 28 and 39 mV in alkaline and acid medium. Moreover, the content of Ir in this catalyst is just around 6 wt%. In conclusion, this paper reports an effective precious metal based HER catalysts with a lower amount of rare metals.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2022
·Vol. 39
·期 4
·2200013
·
IF 3.467
Xinyi Wei,Jinfeng Zhang,Chang Liu,Xiaopeng Han,Yida Deng,Wenbin Hu
The construction of binary metal Pd-based catalysts is an effective strategy to enhance the activity of methanol oxidation reaction. Herein, atomically dispersed Ir single atoms doped to cuboctahedral Pd nanoparticles (Ir-SAs/Pd) as efficient catalysts for alkaline methanol oxidation are prepared via a simple chemical reduction method. The synthetic Ir-SAs/Pd catalysts exhibit the outstanding mass activity of about 1717.3 mA mg Pd −1 compared with pure Pd and commercial Pd/C in electrooxidation for methanol. Meanwhile, the introduction of Ir single atoms enhances the CO tolerance of Pd nanoparticles to a large extent. On the basis of density functional theory results, the enhanced catalytic performance and CO tolerance rely on the effective improvement of the electron dominance near Fermi level and the negative shift of the d-band center for Pd as a result of the electron redistribution between Pd and Ir atoms. This article will provide new insight into the design of high-performance binary metal catalysts for methanol oxidation in alkaline media.
研究领域:
化学
·
材料科学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 12
·期 3
·1017-1024
·
IF 6.119
Guangxia Jin,Guowei Sun,Cheng Fu,Chan Wang,Guoxia Ran,Qijun Song
Iridium nanoparticles (IrNPs) have shown intriguing enzyme-like activities; however, the mechanism behind their versatile enzymatic behaviors is still elusive. A new kind of IrNPs stabilized with β-cyclodextrin (CD) was prepared in this work, and these IrNPs show oxidase-like, catalase-like and peroxidase-like activities. Their catalytic performances were comprehensively studied both by experimental characterization and theoretical calculations. The obtained results were systematically compared with other previously reported IrNPs. It was found that the catalytic properties of the IrNPs are derived from the lattice planes. All the IrNPs could catalyze the degradation of H2O2 due to the presence of the Ir(111) plane, while only the IrNPs with the Ir(220) plane exhibit oxidase-like activity. First of all, a new mechanism for the catalase-like activity of IrNPs was proposed here. The adsorption of H2O2 on IrNPs induces the breakdown of its O–O bond to form ˙OH radicals. The produced ˙OH will then couple with another ˙OH or H2O2, forming the key intermediate species (˙O or ˙OOH) in the production of O2. According to the energy diagrams of H2O2 decomposition on different Ir planes, we suggest that the catalase-like activity is intrinsic to the Ir(111) plane and is independent of other crystal faces or coating agents. In addition, the radicals (˙OH and ˙OOH) generated on different Ir crystal planes show different stabilities and reactivities, which is responsible for the diverse peroxidase-like activities of IrNPs. Finally, the oxidase-like properties are derived from the Ir(220) plane, where the chemisorbed O2 could accept one electron to generate superoxide species. The mechanism revealed in the present work should be helpful for understanding the catalytic role of the lattice planes of IrNPs, which may also be applicable to other metal nanozymes.
研究领域:
生物化学
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纳米生物学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2022
·Vol. 5
·期 4
·3023-3034
·
IF 11.806
Xu Yaoyuan,Zhang Runze,Zhong Zhengxiang,Yang Ling
Sunlight is one of the most significant energy sources that we utilized in our daily life. Although it brings great benefits to us, due to the high energy of the ultraviolet part in sunlight, long time exposure to sunlight may cause severe problems to both humans and materials, such as skin cancer, material fatigue, and degradation. Also, the infrared part of the light can also lead to energy accumulation, heating the surface in an undesirable way. In order to ameliorate the ultraviolet shielding ability of thermochromic materials. In this paper, we synthesized a kind of novel film materials through coordinated self-assembly at room temperature in a very simple and green method. The material is mainly composed of two kinds of metal salts (Cr(NO 3 ) 3 ·9H 2 O and CuSO 4 ·5H 2 O) and octa-aminopropyl POSS, exhibiting great reversible thermochromic property from 20 to 80 ℃, superb UV shielding (100%) performance, and excellent infrared shielding (99%) ability. By increasing the ratio of CuSO 4 ·5H 2 O, the UV shielding effectiveness was enhanced and it achieved nearly 100% along with 99% IR shielding effectiveness at 780–1400 nm when the addition is 50%. The relevant mechanisms were illustrated by decomposition analysis through UV–Vis spectroscopy, in situ XPS, in situ XRD, FT-IR, TG-MS tests, and molecular simulations. These unique properties make this material very promising in various areas, such as new generation smart windows, functional coatings, and temperature sensors. Graphical abstract
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2017
·Vol. 63
·期 9
·3955-3965
·
IF 2.836
Runrun Hong,Yufei He,Junting Feng,Dianqing Li
A series of χ wt % Pd-(1-χ) wt % Ir (χ = 0.75, 0.50, and 0.25) catalysts supported on γ-Al 2 O 3 have been prepared by co-impregnation and calcination-reduction, and subsequently employed in the hydrogenation of 2-ethylanthraquinone—a key step in the manufacture of hydrogen peroxide. Detailed studies showed that the size and structure of the bimetallic Pd–Ir particles vary as a function of Pd/Ir ratio. By virtue of its small metal particle size and the strong interaction between Pd and Ir, the 0.75 wt % Pd–0.25 wt % Ir/Al 2 O 3 catalyst afforded the highest yield of H 2 O 2 , some 25.4% higher than that obtained with the monometallic 1 wt % Pd catalyst. Moreover, the concentration of the undesired byproduct 2-ethyl-5,6,7,8-tetrahydroanthraquinone (H 4 eAQ) formed using the Pd–Ir bimetallic catalysts was much lower than that observed with the pure Pd catalyst, which can be assigned to the geometric and electronic effects caused by the introduction of Ir. © 2017 American Institute of Chemical Engineers AIChE J , 63: 3955–3965, 2017
研究领域:
催化化学
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化学工程
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材料科学
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加氢反应
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工业化学
✓ 已验证
DOI
高影响因子
Discover Nano
·
2025
·Vol. 20
·期 1
·1-17
·
IF 4.5
Li Jigang,Zhao Panchao,Yi Wei
This work shows a detailed investigation on the purification and densification of Ir target from Ir sponge by hydrometallurgy (exchange resin + extraction + chemical precipitation) combined with powder metallurgy (spray drying + pyrolysis + hot press sintering). The detailed influences of refining techniques on each impurity element and content in the Ir purified system are investigated. The controlling mechanisms of Ir particles in spray drying-pyrolysis processing are studied. The densified evolution of Ir particles during hot press sintering is revealed. After the purified treatment, high-purity Ir precursor [(NH 4 ) 2 IrCl 6 ] was achieved. The synthesized Ir particles are spherical, and the average size is about 5 μm. The purity and density of as-sintered Ir target was 99.999 wt% and 99.16%, respectively. This technological integration broke through the limitations of traditional single methods, creating a new path for the preparation of iridium powder. Moreover, atomization drying technology was applied to this research for the first time. The synergy of these technologies significantly improved the preparation efficiency and the stability of product quality. The prepared products could be used as high–reliability contact and electrode materials in the electronic information field, enhancing the performance and service life of equipment. It should be noted that the purified and densified technologies could be used to synthesize other targets of high-purity and high-density requirements.
研究领域:
冶金学
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材料科学
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无机化学
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化学工程
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电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2025
·
IF 5.1
Haoran Bai,Shengyi Yang,Zhenhua Ge,Mingzhu Liu,Mingdong Hong,Ruomin Pang,Xinbing Song,Yurong Jiang,Bingsuo Zou,Libin Tang
Narrow bandgap colloidal quantum dots (CQDs) are ideal materials for realizing high-sensitivity infrared photodetectors. Their use is an effective way to improve the external quantum efficiency (EQE) by utilizing the photomultiplication (PM) effect to achieve highly sensitive photodetection. How to improve the device performance by photomultiplication is still the hot topic in this field. In this work, a simple method of inserting a gold nanoparticles (Au-NPs) film into the PbS QDs active layer to enhance light absorption for the PM-type photodetector ITO/ZnO/PbS/Au-NPs/PbS/P3HT/Ag is presented. In this case, Au-NPs act as the hole traps to induce the tunneling injection of external electrons. As a result, a high responsivity of 1088.86 A W−1 with a high EQE of 138 066% and a specific detectivity (D*) of 1.2 × 1014 Jones is observed from the PM-type photodetector ITO/ZnO(80 nm)/PbS(110 nm)/Au-NPs(4 nm)/PbS(110 nm)/P3HT(140 nm)/Ag under 0.2 μW cm−2 980 nm illumination at −1 V. Furthermore, the device configuration of the photodetector is optimized with the help of COMSOL simulation, and its maximum absorption reaches 91%. In addition, the feasibility of enhancing light absorption through the plasmonic effect has been confirmed by simulating the electric field distribution and carrier distribution within the photodetector.
研究领域:
光电子学
·
纳米技术
·
光子学
·
材料科学
·
半导体器件
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2025
·
IF 2.4
Tong Li,Baokang Jin,Changpeng Lv,Xuemei Shen,Mei Yang
Quinone is a bioactive compound present in some traditional Chinese medicines and participates in numerous biological processes. The carbonyl group in quinone serves as the active center in electrochemical reactions, functioning as an excellent carrier of electron transfer. In this study, in situ Fourier transform infrared (FT-IR) spectroelectrochemistry enables the real-time tracking of three-dimensional (3D) information at molecular level of different substances throughout the electrochemical process. The detection of absorption peaks corresponding to dimerization and hydrogen bonding in the Fourier transform infrared 3D spectra proves that the electrochemical reduction of duroquinone (DQ) in anhydrous acetonitrile involves dimer formation and development of intramolecular hydrogen bonds within monovalent anion radicals. Con sistent with these findings, cyclic voltammetry reveals two pairs of redox peaks and one irreversible anodic peak. Surprisingly, ionic liquids with complex structures of ions, such as 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF 4 ) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF 6 ), make the reduction simpler. Conversely, the transformation of DQ to DQ •- and subsequently to DQ 2- without dimer or hydrogen bond occurring, as clearly observed in the infrared cyclic voltabsorptometry (CVA) and derivative cyclic voltabsorptometry (DCVA). DQ undergoes a straightforward, sequential two-step, one-electron transfer process facilitated by the unique composition of ionic liquids, potentially prompting further evaluation of the roles of cations and anions in ionic liquids.
研究领域:
电化学
·
光谱学
·
分析化学
·
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2024
·
IF 9.5
Israr Muhammad,Humayun Muhammad,Zhang Jiaqi,Shah Khadim,Tan Xin,Chen Chen,Li Yadong
To address the sluggish kinetics of the oxygen evolution reaction (OER), a potential approach is to rationally design and fabricate extremely effective single atom catalysts (SACs). Using an appropriate matrix to stabilize single-atom active centers with optimal geometric and electronic structures is crucial for enhancing catalytic activity. Herein, we report the design and fabrication of Ir single atoms on NiFeZn layered double hydroxide (Ir-SAC/NiFeZn-LDH) electrocatalyst for highly efficient and stable OER. It is investigated that the NiFeZn support exhibits abundant defect sites and unsaturated coordination sites. These sites function to anchor and stabilize single Ir single atoms on the support. The strong synergetic electronic interaction between the Ir single atoms and the NiFeZn matrix resulted in remarkable OER performance of the as-fabricated Ir-SAC/NiFeZn catalyst. With a loading Ir content of 1.09 wt.%, this catalyst demonstrates a highly stable OER activity, with an overpotential of 196 mV at 10 mA·cm −2 and a small Tafel slope of 35 mV·dec −1 for the OER in a 1 M KOH solution. These results significantly surpass the performance of the commercially available IrO 2 catalyst.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2021
·Vol. 15
·期 4
·3065-3072
·
IF 8.897
Du Peng,Huang Kai,Fan Xiaoyuan,Ma Jingteng,Hussain Naveed,Wang Ruyue,Deng Bohan,Ge Binghui,Tang Haolin,Zhang Ru,Lei Ming,Wu Hui
Being a typical state of the art heterogeneous catalyst, supported noble metal catalyst often demonstrates enhanced catalytic properties. However, a facile synthetic method for realizing large-scale and low-cost supported noble metal catalyst is strictly indispensable. To this end, by making use of the strong metal-support interaction (SMSI) and mechanochemical reaction, we introduce an efficient synthetic route to obtain ultrafine Pt and Ir nanoclusters immobilized on diverse substrates by wet chemical milling. We further demonstrate the scaling-up effect of our approach by large-scale ball-milling production of Pt nanoclusters immobilized on TiO 2 substrate. The synthesized Pt/Ir@Co 3 O 4 catalysts exhibit superior oxygen evolution reaction (OER) performance with only 230 and 290 mV overpotential to achieve current density of 10 and 100 mA·cm −2 , beating the catalytic performance of Co 3 O 4 supported Pt or Ir clusters and commercial Ir/C. It is envisioned that the present work strategically directs facile ways for fabricating supported noble metal heterogeneous catalysts.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Yuan Zhang,Liping Kang,Hongmei Li,Xianzhang Huang,Xiaoyu Liu,Lanping Guo,Luqi Huang
The combustion of moxa floss was investigated by thermogravimetric/differential scanning calorimeter (TG/DSC), thermogravimetric/Fourier transform infrared spectroscopy (TG-FTIR) and an infrared radiation spectrum-detecting system. The average mass loss rate at the major stage of combustion was 1.08%/min with a peak at 7.86%/min. Moxa floss burning released the integral heat of 9188 mJ/mg from the temperature of 200 °C to 500 °C. The peak heat flow during char combustion stage was higher than those of other stages. The results indicated the combustion of moxa floss was a mild and slow process, releasing heat continuously and steadily. The infrared radiation spectra of burning moxa stick were in a range of 2.5–13.0 µm and showed double peaks at 3.75 µm and 8.75 µm. Thus, this study provided insight into why moxa floss biomass is the optimal material for thermal therapy and is beneficial for the development of electric thermal stimulation alternative.
研究领域:
热疗研究
·
生物医学工程
·
材料科学
✓ 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）