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Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

《化学科学与工程前沿(英文)》 2022年 第16卷 第3期   页码 364-375 doi: 10.1007/s11705-021-2052-z

摘要: The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells. In this paper, accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading. The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires, as well as their electrochemical performances in a single cell, are investigated. The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires. With increasing reduction temperature, the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40 °C. A mechanism of the Pt nanowires growth is proposed. The optimized Pt nanowires electrode exhibits a power density (based on electrochemical active surface area) 79% higher than conventional Pt/C one. The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.

关键词: Pt nanowires     morphology     structure control     in situ growth mechanism     proton exchange membrane fuel cells    

Enhanced electrocatalytic performance of ultrathin PtNi alloy nanowires for oxygen reduction reaction

Hongjie ZHANG, Yachao ZENG, Longsheng CAO, Limeng YANG, Dahui FANG, Baolian YI, Zhigang SHAO

《能源前沿(英文)》 2017年 第11卷 第3期   页码 260-267 doi: 10.1007/s11708-017-0499-x

摘要: In this paper, ultrathin Pt nanowires (Pt NWs) and PtNi alloy nanowires (PtNi NWs) supported on carbon were synthesized as electrocatalysts for oxygen reduction reaction (ORR). Pt and PtNi NWs catalysts composed of interconnected nanoparticles were prepared by using a soft template method with CTAB as the surface active agent. The physical characterization and electrocatalytic performance of Pt NWs and PtNi NWs catalysts for ORR were investigated and the results were compared with the commercial Pt/C catalyst. The atomic ratio of Pt and Ni in PtNi alloy was approximately 3 to 1. The results show that after alloying with Ni, the binding energy of Pt shifts to higher values, indicating the change of its electronic structure, and that Pt Ni NWs catalyst has a significantly higher electrocatalytic activity and good stability for ORR as compared to Pt NWs and even Pt/C catalyst. The enhanced electrocatalytic activity of Pt Ni NWs catalyst is mainly resulted from the downshifted-band center of Pt caused by the interaction between Pt and Ni in the alloy, which facilitates the desorption of oxygen containing species (O or OH ) and the release of active sites.

关键词: PtNi alloy     nanowires     oxygen reduction reaction     enhanced activity     good stability    

NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 373-386 doi: 10.1007/s11705-022-2223-6

摘要: The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo2O4 nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo2O4 nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF∙cm–2 at the current density of 1 mA∙cm–2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW∙h∙cm–3 at a power density of 180 mW∙cm–3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA∙cm–2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.

关键词: carbon cloth     NiCo2O4 nanowires     core−shell structure     quinone-rich     electric double layer capacitor    

Controlled synthesis of uniform silver nanowires with high aspect ratios in aqueous solutions of gemini

XU Jian, LIU Weijun, LIU Honglai, HU Ying

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 221-227 doi: 10.1007/s11705-007-0040-6

摘要: A simple solution-phase approach has been demonstrated for the large-scale synthesis of silver nanowires with diameters in the range of 15 25 nm, and lengths usually in the range of tens of micrometers. In the presence of gemini surfactant 1,3-bis(cetyldimethylammonium) propane dibromide (16-3-16), the growth of silver could be directed into a highly anisotropic mode to form uniform nanowires with aspect ratios up to about 2,000. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), X-ray powder diffraction (XRD), electron diffraction (ED), and UV-vis absorption spectroscopy, were used to characterize the as-prepared silver nanowires, indicating the formation of a highly pure phase, good crystallinity, as well as a uniform diameter.

关键词: solution-phase     photoelectron spectroscopy     16-3-16     surfactant     transmission    

电沉积Mo和Mo-Co合金纳米线用于互联电阻的电阻率改性 Article

Jun Hwan Moon, Taesoon Kim, Youngmin Lee, Seunghyun Kim, Yanghee Kim, Jae-Pyoung Ahn, Jungwoo Choi, Hyuck Mo Lee, Young Keun Kim

《工程(英文)》 2024年 第32卷 第1期   页码 128-138 doi: 10.1016/j.eng.2023.07.017

摘要:

Achieving historically anticipated improvement in the performance of integrated circuits is challenging, due to the increasing cost and complexity of the required technologies with each new generation. To overcome this limitation, the exploration and development of novel interconnect materials and processes are highly desirable in the microelectronics field. Molybdenum (Mo) is attracting attention as an advanced interconnect material due to its small resistivity size effect and high cohesive energy; however, effective processing methods for such materials have not been widely investigated. Here, we investigate the electrochemical behavior of ions in the confined nanopores that affect the electrical properties and microstructures of nanoscale Mo and Mo–Co alloys prepared via template-assisted electrodeposition. Additives in an electrolyte allow the deposition of extremely pure metal materials, due to their interaction with metal ions and nanopores. In this study, boric acid and tetrabutylammonium bisulfate (TBA) were added to an acetate bath to inhibit the hydrogen evolution reaction. TBA accelerated the reduction of Mo at the surface by inducing surface conduction on the nanopores. Metallic Mo nanowires with a 130 nm diameter synthesized through high-aspect-ratio nanopore engineering exhibited a resistivity of (63.0 ± 17.9) μΩ·cm. We also evaluated the resistivities of Mo–Co alloy nanowires at various compositions toward replacing irreducible conventional barrier/liner layers. An intermetallic compound formed at an Mo composition of 28.6 at%, the resistivity of the Mo–Co nanowire was (58.0 ± 10.6) μΩ·cm, indicating its superior electrical and adhesive properties in comparison with those of conventional barriers such as TaN and TiN. Furthermore, density functional theory and non-equilibrium Green’s function calculations confirmed that the vertical resistance of the via structure constructed from Mo-based materials was 21% lower than that of a conventional Cu/Ta/TaN structure.

关键词: Molybdenum     Molybdenum–cobalt     Interconnect     Microstructure     Electrodeposition     Density functional theory    

标题 作者 时间 类型 操作

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

期刊论文

Enhanced electrocatalytic performance of ultrathin PtNi alloy nanowires for oxygen reduction reaction

Hongjie ZHANG, Yachao ZENG, Longsheng CAO, Limeng YANG, Dahui FANG, Baolian YI, Zhigang SHAO

期刊论文

NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

期刊论文

Controlled synthesis of uniform silver nanowires with high aspect ratios in aqueous solutions of gemini

XU Jian, LIU Weijun, LIU Honglai, HU Ying

期刊论文

电沉积Mo和Mo-Co合金纳米线用于互联电阻的电阻率改性

Jun Hwan Moon, Taesoon Kim, Youngmin Lee, Seunghyun Kim, Yanghee Kim, Jae-Pyoung Ahn, Jungwoo Choi, Hyuck Mo Lee, Young Keun Kim

期刊论文