JOURNAL OF ALLOYS AND COMPOUNDS
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2021
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IF 5.316
Jiangshan Gao,Huanhuan Wang,Yang Zhou,Zhiming Liu,Yan He
The combination of magnetic nanoparticles and transition metal oxides has attracted much attention in microwave absorption applications. Herein, the MnO 2 /Mn 3 O 4 @Ni-Co/graphite carbon (GC) nanocubes with porous structure and ultrathin nanosheets was constructed by self-template strategy and in-situ synthesis. The composites not only synergize the magnetic loss of magnetic Ni-Co nanoparticles with the dielectric losses of GC and MnO 2 /Mn 3 O 4 , but also enhance the multiple interface polarization and improve impedance matching. As a result, the MnO 2 /Mn 3 O 4 @Ni-Co/GC nanocubes present outstanding electromagnetic wave (EMW) absorption performances, in which a RL min of −26 dB at 6.4 GHz with a thickness of 4 mm and an effective absorption bandwidth covering from 5.3 GHz to 6.4 GHz are achieved. Meanwhile, the widest effective absorption bandwidth with the value of 3.7 GHz can be achieved at a matching thickness of 2.0 mm. More importantly, this work provides a new strategy for the synthesis of EMW absorbing materials.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
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IF 7.65
Dandan Song,Xinyu Jiang,Yanshan Li,Xiong Lu,Sunrui Luan,Yuanzhe Wang,Yan Li,Faming Gao
Transition metal oxides (TMOs) derived from metal − organic frameworks (MOF) combined with two-dimensional (2D) transition metal carbides possibly pave an innovative pathway for designing promising biosensors. Herein, a novel electrochemical sensing platform has been fabricated for ultra-sensitive determination of organophosphorus pesticides (OPs), based on MOF-derived MnO 2 /Mn 3 O 4 and Ti 3 C 2 MXene/Au NPs composites. Remarkably, the three-dimensional (3D) MnO 2 /Mn 3 O 4 hierarchical microcuboids derived from Mn-MOF are composed of vertically aligned, highly ordered nanosheets, and further combined with MXene/Au NPs yields synergistic signal amplification effect, with outstanding electrochemical performance, large specific surface area, and good environmental biocompatibility. Under the optimum conditions, the reported sensing platform AChE-Chit/MXene/Au NPs/MnO 2 /Mn 3 O 4 /GCE can be utilized to detect methamidophos in a broad concentration range (10 −12 –10 −6 M), together with a good linearity (R = 0.995). Besides that, the biosensor possesses a low limit of detection (1.34 × 10 −13 M), which far exceeds the maximum residue limits (MRLs) for methamidophos (0.01 mg/kg) established by European Union. Additionally, the feasibility of the proposed biosensor for detecting methamidophos in real samples has been demonstrated with excellent recoveries (95.2%–101.3%). Interestingly, the unique structures and remarkable properties of these composites make them attractive materials for various electrochemical sensors for monitoring either pesticide residuals or other environmentally deleterious chemicals.
研究领域:
材料科学
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环境科学
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生物传感
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2016
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IF 7.145
Zhibin Geng,Yanxiang Wang,Jinghai Liu,Guangshe Li,Liping Li,Keke Huang,Long Yuan,Shouhua Feng
Pure phase manganese oxides have been widely studied as water oxidation catalysts, but further improvement of their activities is much challenging. Herein, we report an effective method to improve the water oxidation activity by fabricating a nanocomposite of Mn3O4 and δ-MnO2 with an active interface. The nanocomposite was achieved by a partial reduction approach which induced an in situ growth of Mn3O4 nanoparticles from the surface of δ-MnO2 nanosheets. The optimum composition was determined to be 38% Mn3O4 and 62% δ-MnO2 as confirmed by X-ray photoelectron spectra (XPS) and X-ray absorption spectra (XAS). The δ-MnO2–Mn3O4 nanocomposite is a highly active water oxidation catalyst with a turnover frequency (TOF) of 0.93 s–1, which is much higher than the individual components of δ-MnO2 and Mn3O4. We consider that the enhanced water oxidation activity could be explained by the active interface between two components. At the phase interface, weak Mn–O bonds are introduced by lattice disorder in the transition of hausmannite phase to birnessite phase, which provides active sites for water oxidation catalysis. Our study illustrates a new view to improve water oxidation activity of manganese oxides.
研究领域:
材料科学
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化学
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
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2019
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IF 6.864
Ling Kang,Chun Huang,Jian Zhang,Mengyao Zhang,Nan Zhang,Yaqin He,Chen Luo,Chaolun Wang,Xiaofeng Zhou,Xing Wu
The intrinsically low electrical conductivity and the poor cycling stability are two major obstacles of manganese oxides to hamper their further application in high-performance supercapacitors . One effective way to enhance their electrochemical properties is construction of appropriate nanocomposite with different structures. Herein, we demonstrated the fabrication of a hierarchical MnO 2 nanowires-Mn 3 O 4 nanoparticles nanocomposite by an effective and innovative two-step synthesis strategy. Further, the Mn 3 O 4 nanoparticles were exfoliated from the surface of α -MnO 2 nanowires . And the optimum composition was calculated to be ~ 35% Mn 3 O 4 and ~ 65% α -MnO 2 . The capacitance of the optimized MnO 2 –Mn 3 O 4 nanocomposite electrode reaches 278.2 F g −1 at a current density of 20 A g −1 , and the capacitance retained at 99.3% even after 5000 cycles. The asymmetric supercapacitor was also fabricated with optimized MnO 2 –Mn 3 O 4 as the positive electrode and activated carbon as the negative electrode . It could deliver an excellent energy density of ~ 41.3 Wh kg −1 at a power density of ~ 1153W kg −1 . And the superior cycling stability achieves as well. The excellent capacitance properties of the MnO 2 –Mn 3 O 4 nanocomposite can be attributed to the hybrid structure, in which one-dimension α -MnO 2 nanowires provide a super highway for electron and ion transfer and Mn 3 O 4 nanoparticles attached offer the abundant pseudocapacitive sites for charge storage.
研究领域:
材料科学
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能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）