SURFACE AND INTERFACE ANALYSIS
·
2014
·Vol. 47
·期 2
·270-277
·
IF 1.393
Yongli Shi,Suying Ma,Ruiqiong Tian,Yingge Zhao,Qian Jiao,Xu Ma,Qing Shang
A novel amphiphilic copolymer was synthesized from poly (ethylene glycol) methyl ether methacrylate (PEGMA950), methyl methacrylate (MMA) and acryloyl- β -cyclodextrin (acryloyl- β -CD) using the composites of (NH 4 ) 2 S 2 O 8 /NaHSO 3 as the oxidation–reduction initiators. The successful fabrication of poly(PEGMA-co-MMA-co-acryloyl- β -CD) copolymers was confirmed by Fourier transform infrared spectrometer (FTIR), 1 H-nuclear magnetic resonance ( 1 H NMR) spectra. The amphiphilic copolymer could self-assemble into nanoparticles (NPs), and their morphology and particle size distribution were characterized with transmission electron microscopy (TEM), atomic force microscope (AFM) and dynamic light scattering (DLS) methods. Ibuprofen (IBU) was encapsulated in the novel NPs, and the release profiles of IBU were investigated. FTIR and 1 H NMR spectra illustrated that the poly(PEGMA-co-MMA-co-acryloyl- β -CD) copolymers were synthesized without any residual monomers and initiators. TEM and AFM photographs suggested that the obtained NPs were spherical, and the DLS results indicated that the diameter of blank NPs was 157.3 ± 32.7 nm. The IBU release profile showed that the IBU-loaded NPs had certain pH responsibility. Copyright © 2014 John Wiley & Sons, Ltd.
研究领域:
材料科学
·
药剂学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2022
·Vol. 46
·期 13
·19221-19232
·
IF 4.672
Vi Thuy Thi Phan,Toan Minh Pham,Hau Quoc Pham,Tai Thien Huynh,Thi Hong Tham Nguyen,Van Thi Thanh Ho
Summary Highly stable and cost-effective electrocatalysts are of importance in regulating energy conversion efficiency and commercial feasibility of direct methanol fuel cells (DMFCs). So far, integrating transition metals into Pt-based catalysts to enhance their catalytic performances for methanol electro-oxidation reaction (MOR) at the anode of DMFCs has received significant interest. This study witnessed the first time of depositing Pt 3 Co 1 alloy nanoparticles (NPs) on robust Ti 0.9 Ir 0.1 O 2 supports utilizing a modified reduction method that used NaBH 4 as a reducing agent in the absence of surfactants or stabilizers. This novel combination not only reduces the usage of costly and easily-deactivated Pt but also significantly improves catalytic activity and poisoning tolerance for MOR. Regarding electrocatalytic performance, the onset potential and the mass activity of the Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst are ~0.1 V vs NHE and 316.16 mA/mg Pt , respectively, which are 4.5-fold lower and 1.5-fold higher than the corresponding figures for the commercial Pt/C (E-TEK) catalyst, ~0.45 vs NHE and 206.83 mA/mg Pt , indicating superior catalytic activity and CO-tolerance of the former over the latter. Furthermore, the superior anti-poisoning ability and stability of the Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst are demonstrated by its 2.2-fold higher I f /I b ratio in MOR and lower degradation rate in the 60-min chronoamperometry (CA) and 3000-cycle scanning tests than the Pt/C counterpart. These enhancements could be abscribed to synergistic influence between the Pt-Co alloy NPs and the robust Ti 0.9 Ir 0.1 O 2 support. The addition of Co into the catalyst to promote removal of Pt-poisoning species as well as the use of highly corrosion-resistant Ir-doped TiO 2 as a catalyst support play a decisive role in boosting electrochemical behaviors of the Pt 3 Co 1 / Ti 0.9 Ir 0.1 O 2 catalyst. Generally, the success of this work in synthesizing high-performance Pt 3 Co 1 /Ti 0.9 Ir 0.1 O 2 catalyst could serve as groundwork for further development of TiO 2 -based material supported bimetallic catalysts for applications in the electrochemical catalysis field.
研究领域:
材料科学
·
电化学催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Le Zhang,Xin Zhou,Shaohua Chai,Jian Guan,Guijun Fan,Wuxinchen Yang,Guojun Ma,Ning Han,Yunfa Chen
There is a high demand to synthesize ozone decomposition catalysts especially in high-space-velocity and high-relative-humidity (RH) environments. Herein, two polymorphs of cobalt hydroxide, α- and β-Co(OH)2, are synthesized and applied for ozone elimination. β-Co(OH)2 shows ∼90% ozone decomposition efficiency under high space velocity (weight hourly space velocity (WHSV) = 1,200,000 mL g–1 h–1, 25 °C, 40 ppm), which is far higher than that of α-Co(OH)2 (∼5%). β-Co(OH)2 has high spin Co(II) in distorted octahedral coordination caused by the Jahn-Teller effect, leading to a higher crystal field splitting energy level and thus contributing to the easier electron transfer between the ozone and catalyst. Moreover, β-Co(OH)2 still shows high performance (∼87%) even in humid conditions (RH ∼50%, 25 °C, 40 ppm, WHSV = 600,000 mL g–1 h–1), which is attributable to its abundant surface non-hydrogen-bonded hydroxyls weakening water molecule adsorption, providing an idea to develop highly efficient catalysts for ozone decomposition in humid environments.
研究领域:
材料科学
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催化
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环境科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jiaming Wang,Huixian Zhong,Kang An,Qiang Liu,Wu Jin,Yuan Liu
In this work, Ni–Co alloy nanoparticles (NPs) on La-doped SiO2 showed excellent selectivity toward ethanol for direct ethanol synthesis via CO hydrogenation. Over the catalyst with an optimal ratio of Ni/Co, the total alcohol selectivity reached 33.5%, of which ethanol occupied 47.0 wt %. The results demonstrated that the interaction between Co and Ni improved the ability to activate H2 and CO and adjusted the amount of the dissociatively and associatively adsorbed CO. Besides, the mutual dilution of nickel and cobalt in Ni–Co alloy NPs effectively reduced the isolated Co or Ni-clusters; thus, the formation of heavy hydrocarbons was suppressed. In the reaction process, Ni@Co–Co2C, a core–shell composite with a nickel core and Co–Co2C shell, was formed, which suppressed the loss of nickel species. Moreover, with the reaction going on, a small amount of poorly alloyed Co-clusters would be covered gradually by the formed coke, resulting in an increase in alcohol selectivity.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy Materials
·
2025
·
IF 26
Zongge Li,Wenjun Kang,Jingkai Lin,Rui Li,Konggang Qu,Suyuan Zeng,Lei Wang,Fanpeng Meng,Huayang Zhang,Haibo Li
The oxygen electrocatalytic activity of transition metal catalysts can be tuned by tailoring their microstructure to optimize electronic configuration. Here, a one-step Coordination-Selective Synthesis strategy is developed to integrate Co single-atom sites and Fe-based nanoparticles within the same matrix, enabling long-range electronic interactions that enhance Co-N 4 reactivity and improve oxygen reduction reaction performance. X-ray absorption spectroscopy confirmed that remote Fe-based nanoparticles modulate the electron distribution at Co-N 4 sites. Structural characterizations reveal that the optimal catalyst, Co 50% Fe 50% -NC, contains metallic Fe, Fe 3 O 4 , and Fe 4 N species. Electrochemical measurements show that it achieves onset and half-wave potentials of 0.984 and 0.927 V versus RHE, surpassing Co 100% -NC with only Co-N 4 sites. Additionally, it demonstrates efficient oxygen evolution reaction performance, achieving an overpotential of 298 mV at 20 mA cm −2 , comparable to RuO 2 . Density functional theory calculations reveal that Fe 4 N optimizes O-containing intermediate adsorption/desorption, lowering the theoretical overpotential. Zn-air batteries assembled with Co 50% Fe 50% -NC exhibited superior performance to Pt/C, highlighting its potential for bifunctional oxygen electrocatalysis. This study provides an approach for designing high-performance catalysts by utilizing synergistic interactions between atomic and nanoscale metal species.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2020
·
IF 12.35
Shangbo Ning,Hua Xu,Yuhang Qi,Lizhu Song,Qiqi Zhang,Shuxin Ouyang,Jinhua Ye
The transformation of CO2 into a single product is a critical scientific challenge because of the difficulty associated with targeted activation and conversion of CO2 by heterogeneous catalysts. Herein, we present an atomic-scale dispersed Co–N species anchored Co@C hybrid structure (entitled as Co@CoN&C) that regulates catalytic properties in thermodynamic and kinetic processes to achieve active and highly selective CO yield in the photothermal CO2 reduction. An optimal sample delivers the maximum yield rate of 132 mmol gcat.–1 h–1 and remarkable CO selectivity (91.1%), while the undesirable methanation activity, compared with typical Co nanoparticles (NPs), was suppressed. The mechanism study suggests that the strong photon–matter interaction over graphitic-carbon and Co NPs can enhance the light-to-heat conversion efficiency and thus induce the high work temperature, which is thermodynamically beneficial for CO2 activation and subsequently promoted the catalytic activity. Furthermore, the carbon layers improve the adsorption of CO2, and the surface atomically dispersed Co–N species weakens hydrogenation capability, which kinetically controls the reaction pathway and therefore attains the high selectivity for CO production. This study exemplifies that the microstructure design can modulate the thermodynamic and kinetic factors of photochemical reaction and thereby achieve potential solar-to-chemical energy conversion.
研究领域:
材料科学
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催化化学
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Ziwen Yao,Jing Li,Shuai Nie,Yuan Wang,Xitao Yin,Yunxia He
Utilizing p-n composite materials for the fabrication of metal-oxide semiconductor (MOS) gas sensors represents a promising strategy to achieve exceptional selectivity in detecting reducing gases such as hydrogen (H₂) and carbon monoxide (CO). However, previous studies have typically achieved this selectivity under fixed operating temperatures and single molar ratios. This study presents the successful synthesis of n-In₂O₃/p-Co₃O₄ nanoparticles, featuring a p-n heterojunction structure, using a simple composite preparation method. The gas-sensing properties, crystal structure, morphology, and chemical states were comprehensively characterized using an electrochemical workstation, XRD, TEM, HRTEM, and XPS. Experimental results show that the gas sensor responses of the n-In₂O₃/p-xCo₃O₄ composites (with x = 10.5, 15, 18, 21), annealed at 500°C within an operational temperature range of 350°C to 400°C, exhibit distinct behaviors for CO and H₂ gases. This addresses the challenge of achieving selective detection across varying conditions. Notably, the n-In₂O₃/p-18Co₃O₄ composites display opposing response characteristics for both gases across a broad temperature range of 200°C to 400°C. At 350°C, the n-In₂O₃/p-18Co₃O₄ sensor demonstrates optimal selectivity, significantly minimizing cross-sensitivity and improving detection accuracy and reliability. The sensor also shows excellent stability, with consistent responses under repetitive exposure conditions. By improving both sensor selectivity and stability, this research advances gas detection technologies, with potential applications in sustainable energy and public health monitoring.
研究领域:
材料科学
·
传感器技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2024
·
IF 3.3
Tao Wang,Benlong Yu,Long Mu,Zhilin Chen,Chao Xiao,Shuming Peng
The palladium oxide phase (PdOx) plays a critical role in catalytic methane oxidation and CO oxidation reactions. Precise characterization of supported PdOx by CO-FTIR spectroscopy is often accompanied by the reduction of PdOx by CO. Lowering the CO partial pressure to 0.05% CO/N2 (0.5 mbar) and the adsorption temperature to −130 °C is a proper condition to inhibit the reduction completely. Then CO-FTIR spectroscopy was conducted on a series of supported PdOx catalysts. We find that CO adsorbed on coordinatively unsaturated Pd atoms (Pdcus) on the PdOx surface gives three adsorption bands at ∼2145 cm–1. Three types of surface Pdcus atoms with different degrees of coordination unsaturation (types I, II, and III) exist in supported PdOx catalysts; their νCO are located at 2133, 2145, and 2160 cm–1, respectively. The order of coordination unsaturation of surface Pdcus should be type III < type II < type I. Since νCO of surface Pdcus is between νCO of Pd2+(CO) and Pd+(CO), the effective charge of surface Pdcus is 1 < n < 2. For small PdOx clusters in zeolite-supported PdOx catalysts, surface Pdcus atoms with more coordination unsaturation (i.e., step, edge, and corner sites) are more abundant, leading to greater IR intensity of adsorbed CO.
研究领域:
催化化学
·
表面化学
·
光谱学
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材料科学
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环境化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Pengcheng Wang,Qingqing Jiang,XingYu Li,Xuedong Wang,Juncheng Hu
Generally, researchers focus on the regulation of metal sites rather than surrounding nonmetals in photothermal CO 2 hydrogenation reaction. Herein, concerning the role of non-metallic N species, a series of Co/NC-T catalysts have been fabricated via high-temperature pyrolysis of Zeolitic Imidazolate Frameworks-67. The CO 2 conversion rate shows a consistent tendency with the ratio of graphitized-N species while the product selectivity is closely related to the coordination state of Co-N x species. Co/NC-800 catalyst achieves high CO 2 conversion rate of 758 mmol g cat -1 h -1 with CH 4 selectivity of 99.6 %. After adding extra graphitized-N species, the CO 2 conversion rate could further enhance to 80.2 % for N-Co/NC-2. The role of N species in photothermal CO 2 hydrogenation reaction has been investigated in details, providing new insights for the design of metal organic frameworks derived metal/N-doped carbon catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Cheng Lv,Jiayan Huang,Yuang QI,Qingjie He,Yazhou Wang,Cuili Xiang,Yongjin Zou,Fen Xu,Lixian Sun
MgH₂ is one of the most promising materials for solid hydrogen storage and is environmentally friendly primarily owing to its high mass hydrogen storage density (7.6 %). However, the application and development of MgH₂ are limited by its sluggish kinetics, requiring high processing temperatures. In this study, we prepared Ni/Co-co-doped Ti 2 VC 2 bimetallic MXene nanosheets via etching and the hydrothermal method. These nanosheets were then doped into MgH₂, resulting in drastically improved hydrogen storage properties. The MgH₂-based composite hydrogen storage materials doped with 10 wt% Ni/Co–Ti 2 VC₂ (TVCNC) commenced hydrogen emission from 183 °C and could emit 6.65 wt% hydrogen at 300 °C. During the rehydrogenation test, the composites could still absorb hydrogen at 5.0 wt% within a 10 min window at a hydrogen pressure of 20 bar at 125 °C. Moreover, the hydrogen absorption and emission kinetics of the doped MgH₂ were considerably improved. This improvement could be ascribed to the significantly increased specific surface area of the MXene nanosheets after etching, which increased the number of active sites on the surface to accelerate the reaction, thereby accelerating hydrogen adsorption and emission. In addition, the migration of electrons between the multivalent Ti ions as well as between Ni and Co helped accelerate bond cleavage between magnesium and hydrogen, thereby enhancing the kinetic properties. Ni/Co co-doping produced Mg 2 Ni alloys with magnesium via hydrogen adsorption and emission, thus improving the reaction kinetics of the composites.
研究领域:
材料科学
·
能源储存
✓ 已验证
产品关联
DOI
高影响因子
Energy Advances
·
2024
·
IF 3.2
Kunpeng Liu,Xu Wang,Nan Wang,Ruiyong Zhang,Meinan Yang,Baorong Hou,Wolfgang Sand
Rationally designing high-efficiency catalysts for electrochemical two-electron water oxidation reaction (2e− WOR) to produce hydrogen peroxide (H2O2) is extremely important, while designing bimetallic metal–organic frameworks (MOFs) is of great significance for effective 2e− WOR. Herein, MIL-53(Fe) and different proportions of Co-doped MIL-53(Fe) were prepared by a hydrothermal method. The structural characterization and elemental analysis showed that the Co ions were successfully doped into MIL-53(Fe) to form a MIL-53(Fe/Co) bimetallic MOF, and the morphology of MIL-53(Fe/Co) became more regular after Co doping. We found that the optimized MIL-53(Fe/Co) exhibits remarkable 2e− WOR performance, which gave an overpotential of 150 mV at 1 mA cm−2. The overpotential of MIL-53(Fe/Co) was approximately 220 mV (at 1 mA cm−2) lower than that of MIL-53(Fe), which may be attributed to the change of microstructure of MIL-53(Fe) after Co doping and the synergistic effect between Fe/Co. Our work introduces a strategy for designing bimetallic MOF-based electrocatalysts, opening up new possibilities for efficient 2e− WOR systems.
研究领域:
材料科学
·
电催化
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Hanlin Wang,Haibo Liu,Xuehua Zou,Fuwei Sun,Luyao Wang,Jingchao Hu,Dong Chen,Meng Liu,Jianfei Shen,Tianhu Chen
In this work, the effect of Co substitution in the Fe 1-x S (CSP) on the activation of H 2 O 2 to degrade tetracycline (TC) is investigated. A series of CSP samples with different Co content are synthesized via a high-temperature sulfidation method and characterized by XRD , XPS , SEM, and electrochemical analysis . The result showed that low Co content (≤1%) promotes the catalytic activity of Fe 1-x S, while excessive Co (1%﹤x ≤ 3%) inhibits its catalytic activity. The investigation of Behnajady-Modirshahla-Ghanbery kinetic model (BMG) showed that the maximum initial degradation rate of TC over 1.0% CSP/H 2 O 2 was 1.6 times than that of in CSP/H 2 O 2 system. The Box-Behnken with Response Surface Methodology was employed to verify optimum condition for TC degradation. The quenching experiments and ESR determined that ·OH, ·O 2 − and 1 O 2 were involved in TC degradation with the treatment of 1.0% CSP/H 2 O 2 system. Electrochemical analysis, ·OH quantification, and metal ion concentrations measure reveal that Co substitution accelerates electron transfer efficiency and Fe 2+ regeneration. Furthermore, nine intermediates are identified and the possible degradation pathway of TC is proposed. The unique effect of Co provides novel insight and efficient strategies for improving the reactivity of iron sulfide.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）