AIP Advances
·
2017
·Vol. 7
·期 10
·
IF 1.568
Luo Jiangqi,Fu Qiong,Wang Haiyun,Zhao Dongmei,Luo Laihui,Li Weiping
In order to seek for the single-phase multiferroic metal-organic frameworks (MOFs) materials, we prepared a multiferroic material [NH 2 -CH + -NH 2 ]Co(HCOO) 3 (FMDCo) by solvothermal method. We found that it had weak ferromagnetism below 12.5 K with the coercive fields ( H c ) of 560 Oe, remnant magnetization ( M r ) of 7.67 emu/g and saturation magnetization ( M s ) of 10.3 emu/g and exhibited obvious dielectric relaxation. The octahedral metal ions (Co 2+ ) were linked by formate (HCOO - ) ligands. The AmineH + cation (NH 2 -CH + -NH 2 ) were located within the cube-like cavities of the framework and formed extensive hydrogen bonds with the framework. This improved the phase transition temperature and thermal stability. This finding helps to understand the nature of magnetic and electric ordering in the MOFs.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
Science China-Chemistry
·
2026
·
IF 9.7
Zheng Xia,Fu Yaoqiang,Ning Jing,Wang Haorui,Liu Hongfei,Cui Chunhua
Direct formate fuel cells (DFFCs) are becoming one of the most promising next-generation energy devices owing to their high energy density, low toxicity, and carbon neutrality. However, their practical application is hindered by the sluggish kinetics of the formate oxidation reaction (FOR) on conventional palladium (Pd)-based catalysts due to the strong adsorption of hydrogen intermediates (H ads ) that block the active sites. Herein, we tackled the above problem by tailoring the Pd electrocatalytic properties through the interfacial interaction with the hydroxyl group-abundant and oxophilic Co(OH) 2 substrate. This resulted in an impressive mass activity of 5.02 A mg
−1 Pd
for the synthesized Pd/Co(OH) 2 , approximately three times that of commercial Pd/C. Moreover, under high formate concentration, Pd/Co(OH) 2 exhibits significantly improved stability, i.e. , up to 24000 s sustainable current density with 100% selectivity toward CO 2 (CO 2 is actually converted to carbonate in alkaline media). Kinetic isotope effect (KIE) analysis and in situ Raman spectroscopy based mechanistic study reveal the excellent FOR performance of Pd/Co(OH) 2 originates from the partially oxidized Pd facilitated H ads oxidative removal and the more hydrophilic surface induced competitive HCOO − adsorption over H ads . This study demonstrates a rational strategy to optimize the Pd-based FOR electrocatalysts through the electronic and interfacial interactions with appropriate substrate to modulate the key intermediate adsorption-reaction kinetics.
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产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2025
·
IF 6.6
Zhenyu He,Chi Zhang,Xiaomeng She,Zhuanfei Liu,Zhaoyong Zou,Song Zhang,Hongwei Liu,Jian Peng,Rong Tu
The low corrosion resistance of magnesium alloys directly limits their applications in natural environments. In this work, a superhydrophobic and corrosion-resistant coating was prepared on AZ31 magnesium alloys using a combination of a sodium formate hydrothermal reaction and fluoroalkyl silane cross-linking. The hydrothermal treatment successfully generates a corrosion-resistant Mg(HCOO) 0·4 (OH) 1.6 coating on the magnesium alloy surface, which exhibits a multi-scale microstructure, such as nanoscale stacking and microscale nanoflowers. The low surface energy modification of this micro-nano rough surface with fluoroalkyl silane imparted superhydrophobic properties. The coating has a corrosion inhibition efficiency of 99.999 % based on the lowest corrosion current density, i.e.,1.23 × 10 −9 Acm −2 . Furthermore, the superhydrophobic coating maintains good corrosion resistance even after 30-day immersion in simulated seawater. The low frequency impedance remains 10 5 Ωcm 2 during the growth cycle of A. niger . The static contact angle of the coating is 151.4°, attributed to the high-density –CF 2 - and –CF 3 groups on the surface. This work provides new insights into the preparation of superhydrophobic coatings on AZ31 magnesium alloys to significantly enhance their corrosion resistance.
研究领域:
材料科学
·
腐蚀工程
·
表面化学
·
疏水材料
·
金属防护
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产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2020
·
IF 4.419
Woo Sung Yum,Jung-Il Suh,Do Hoon Kim,Jae Eun Oh
Recently, the combined use of calcium oxide (CaO) and calcium formate (Ca(HCOO) 2 ) has been proposed as an alternative activator for ground granulated blast furnace slag (GGBFS) (referred to as CaO-Ca(HCOO) 2 -activated GGBFS system). However, this clinker-free binder system produces calcium aluminate hydrate (C 2 AH 8 ), generally leading to the degradation of cementitious binder systems by its conversion to other phases. Thus, in this study, attempts to remove C 2 AH 8 from this system without losing the strength are suggested by the use of two additives (i.e., calcium sulfate (CaSO 4 ) and calcium nitrate (Ca(NO 3 ) 2 ), respectively). Results revealed that the above-mentioned additives completely remove C 2 AH 8 in the initial curing stage via its conversion to ettringite or NO 3 - and NO 2 -AFm, respectively. In addition, the additives reduced the extent of the total shrinkage and the standard deviation of strength results of triplicate samples. However, CaSO 4 exerted a beneficial effect on the strength, while Ca(NO 3 ) 2 exerted a marginal or detrimental effect on the strength. Therefore, this study suggested a new mixture form of an activator, comprising CaO , Ca(HCOO) 2 , and CaSO 4 , to activate GGBFS for maintaining strength without the conversion issue of C 2 AH 8 .
研究领域:
建筑材料学
·
材料科学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2019
·
IF 2.961
Mingzhou Zhao,Qiong Fu,Peng Du,Yafei Hou,Laihui Luo,Weiping Li
The thermal stable Eu(HCOO) 3 red-emitting crystals were synthesized by a facile hydrothermal route. Both excitation and emission spectra revealed that the prepared crystals can be efficiently pumped by the near-ultraviolet (NUV) light and it can emit brightness red light with admirable color purity of 90.4%. With the help of Judd-Ofelt theory, the optical transition intensity parameters of Eu 3+ ions were evaluated so as to explore its local symmetry performance in the Eu(HCOO) 3 host lattices . The thermal quenching behaviors of the studied samples were investigated through the temperature-dependent emission spectra . Ultimately, a white light-emitting diode (WLED) lamp with good color rendering index (78.2) and correlated color temperature (6386 K) was packaged through coating the tricolor phosphors (BaMgAl 10 O 7 :Eu 2+ blue-emitting phosphor, (Ba,Sr) 2 SiO 4 :Eu 2+ green-emitting phosphor and resultant red-emitting crystals) onto the surface of a NUV chip. These results disclosed the high brightness Eu(HCOO) 3 red-emitting crystals were suitable for NUV chip triggered WLED applications.
研究领域:
材料科学
·
光学材料
·
固态照明
·
发光学
·
无机化学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Fang Li,Geun Ho Gu,Changhyeok Choi,Praveen Kolla,Song Hong,Tai-Sing Wu,Yun-Liang Soo,Justus Masa,Sanjeev Mukerjee,Yousung Jung,Jieshan Qiu,Zhenyu Sun
We report a unique 2D bismuth metal-organic framework (Bi-MOF) that possesses permanent accessible porosity for efficient electrochemical CO 2 reduction (ECR) to HCOOH. The 2D open-framework structure with helical Bi-O rods bridged by tritopic carboxylate ligands exhibits a remarkable Faradaic efficiency for HCOOH formation over a broad potential window, reaching 92.2 % at ∼ –0.9 V ( vs . reversible hydrogen electrode, RHE) with excellent durability over 30 h. The mass-specific HCOOH partial current density is up to 41.0 mA mg Bi −1 , exceeding 4 times higher than that of commercial Bi 2 O 3 and Bi sheets at ∼ –1.1 V ( vs . RHE). Operando and ex-situ X-ray absorption fine structure spectroscopy revealed a structural feature associated with Bi-MOF to preserve Bi(3+) during and after long-term ECR. Theoretical calculations further showed that the crystallographically channels with abundant Bi active sites in the MOF structure favor the formation of *HCOO while suppressing the side-reaction of hydrogen evolution, thereby leading to the high selectivity for HCOOH.
研究领域:
材料科学
·
电化学
·
环境科学
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产品关联
DOI
高影响因子
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