CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
P. Ning,C.C. Liu,Y.J. Wang,X.Z. Li,R. Ranjithkumar,Z.H. Gan,Y.Y. Wu,T. Fu
Magnetic MnFe 2 O 4 nanoparticles containing 0, 1 and 3 at.% silver, respectively were synthesized by one-pot sol-gel method for antibacterial applications in biomedical fields. Material characterizations indicate that MnFe 2 O 4 begins crystallization at 134 °C and oxidation at 450 °C, the grain size and agglomeration degree increase with the silver content and silver exists as metallic state for the particles. The saturation magnetization decreases with the sintering temperature and slightly increases with the silver content, with the maximum of 50.0 emu/g obtained. Antibacterial tests by plate counting and PI-Hoechst 33342 staining suggest that the antibacterial activity of Ag–MnFe 2 O 4 nanoparticles is silver content-dependent. Silver ions concentration measurement, β-galactosidase activity assay and transmission electron microscopic observation show that the antibacterial activity is dominated by the actions of the released silver ions, rather than the membrane cell impairment or reactive oxygen species-induced oxidative stress mechanism. MC3T3-E1 cell test demonstrates the best cytocompatibility of the nanoparticles with 3 at.% silver, which is likely related to the reduced cell endocytosis of the aggregated particles. The combination of magnetism , antibacterial activity and biocompatibility would make Ag–MnFe 2 O 4 nanoparticles a potential multi-functional material in various biomedical applications.
研究领域:
材料科学
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纳米技术
·
生物医学工程
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 12
·1550
·
IF 4.146
Hongzhou Dong,Yingjie Chen,Chong Gong,Lina Sui,Qiong Sun,Kangle Lv,Lifeng Dong
Due to slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) during discharging and charging processes, it is essential to rationally design and synthesize non-precious metal bifunctional electrocatalysts with good performance for metal-air batteries. Herein, Ag-MnFe2O4heterojunction nanoparticles supported on N, S, P-codoped graphene (NSPG) are developed with enhanced ORR and OER bifunctional electrocatalytic activities and stability. In contrast, S, P-doped graphene (SPG) and N, P-doped graphene (NPG) show less stabilization for the heterojunction particles. For example, under alkaline conditions, the ORR half-wave potential of Ag-MnFe2O4/NSPG can reach 0.831 V, and the over potential for OER is 0.56 V at the current density 10 mA·cm−2. Furthermore, Ag-MnFe2O4/NSPG shows better methanol resistance and durability than Pt/C catalysts.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Yingjie Chen,Shiben Liu,Liyan Yu,Qiuhong Liu,Yongtao Wang,Lifeng Dong
Nanoparticles with core–shell or hollow interiors have immense potential for catalysis. Herein, Ag@M x Fe 3− x O 4 (M = Co, Mn) core–shell nanoparticles were firstly synthesized through a seed-mediated method. These particles were then loaded onto carbon catalyst supports to form Ag@M x Fe 3− x O 4 /C. Then, hollow-M x Fe 3− x O 4 /C was prepared with the diffusion of Ag from Ag@M x Fe 3− x O 4 /C in saturated NaCl solution at room temperature . As a result, Ag@MnFe 2 O 4 /C demonstrates better oxygen reduction reaction (ORR) activity than Ag@CoFe 2 O 4 /C and other Ag@Mn x Fe 3− x O 4 /C with various Mn/Fe ratios. Moreover, Ag@MFe 2 O 4 /C shows superior ORR catalytic activities over hollow-MFe 2 O 4 /C, which can be due to electronic coupling between Ag core and MFe 2 O 4 shell. Furthermore, Ag@MnFe 2 O 4 /C catalysts demonstrate high durability for the ORR in alkaline media and insensitivity to methanol. These findings will provide helpful guidance for design and fabrication of carbon-supported core–shell catalysts for ORR in the future.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Yingjie Chen,Zhihao Shi,Shanshan Li,Jianguang Feng,Beili Pang,Liyan Yu,Wenwu Zhang,Lifeng Dong
Heterogeneous nanoparticles with synergistic effects between different composites are potential catalysts with bifunctional catalytic activity for oxygen reduction (ORR) and oxygen evolution reaction (OER). Herein, heteroatoms such as N and S are doped into graphene substrates to improve catalytic activity and structural stability of Ag-MnFe 2 O 4 nanoparticles. Interestingly, these particles keep a primarily heterogeneous structure for their assembly on N, S-codoped graphene (NSG), while Ag domains shrink on S-doped graphene (SG) or N-doped graphene (NG). Subsequently, Ag-MnFe 2 O 4 /NSG shows the best bifunctional catalytic activity due to the improved stability of Ag-MnFe 2 O 4 NPs on NSG and enhanced bonding energy between supports and particles. The Koutecky-Levich plots confirm a major four-electron reaction pathway for the ORRs on Ag-MnFe 2 O 4 /NSG. Meanwhile, Ag-MnFe 2 O 4 /NSG exhibits higher stability and better methanol tolerance than commercial Pt/C. Therefore, Ag-MnFe 2 O 4 /NSG with bi-functional catalytic activity for ORR and OER is a promising non-Pt catalyst candidate.
研究领域:
材料科学
·
电化学
✓ 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）