Search query: 2D PtNi alloy

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abstract: Two dimensional CdS based hybrid nanostructures are intriguing materials with an application prospect in different fields such as sensing (i. e. photoresistors) and solar energy harvesting (photocatalysis, photovoltaics, and so forth) We report herein a colloidal synthetic path for interfacing metal and semiconductor with 2D CdS nanoplates. Selective growth of Au, Pt, and a PtNi alloy as well as Cu2 xS semiconductor is achieved on CdS nanoplates using controlled reduction of metallic precursors and thermal decomposition of a metal sulfide single source precursor using standard organic phase colloidal chemistry.
author_names: Helena Fridman

Liang Tian

Karam Shreteh

Michael Volokh

Taleb Mokari
title: Selective Growth of Metal Sulfide, Metal, and Metal Alloy on 2D CdS Nanoplates
venue: Frontiers in Materials
year: 2019

abstract: A computer analysis of the deformation mode of a billet and tool in the axially symmetric statement at the stage of established drawing of the PtNi alloy of the equiatomic composition is performed by the finite element method in the DEFORM 2D program medium. The geometry of the diamond tool providing a decrease in rigidity and weight without varying the basic parameters of the production process is proposed.
author_names: Olga M Ogorodnikova

Evgeniy Borodin
title: Computer analysis of the deformation mode of the drawing tool for platinum alloys
venue: Russian Journal of Non Ferrous Metals
year: 2016

abstract: The computer analysis was made to evaluate the stress state of a workpiece and an axisymmetrically positioned tool at the stage of steady drawing process of PtNi equiatomic alloy using finite element method in the DEFORM 2D software environment. The diamond tool geometry is proposed to reduce hardness and weight without changing basic process parameters.
author_names: Array M Ogorodnikova

Array M Borodin
title: KOMP'IuTERNYI ANALIZ NAPRIaZhENNO DEFORMIROVANNOGO SOSTOIaNIIa INSTRUMENTA DLIa VOLOChENIIa PLATINOVYKh SPLAVOV
year: 2016

abstract: The catalytic performance of Pt based catalysts for oxygen reduction reactions (ORR) can generally be enhanced by constructing high index exposed facets (HIFs) However, the synthesis of Pt alloyed high index skins on 1D non Pt surfaces to further improve Pt utilization and stability remains a fundamental challenge for practical nanocrystals. In this work, Pd nanowires (NWs) are selected as a rational medium to facilitate the epitaxial growth of Pt and Ni. Based on the different nucleation and growth habits of Pt and Ni, a continuous PtNi alloy skin bounded with HIFs spiraled on a Pd core can be obtained. Here, the as prepared helical Pd@PtNi NWs possess high HIF densities, low Pt contents, and optimized oxygen adsorption energies, demonstrating an enhanced ORR mass activity of 1.75 A mgPt 1 and a specific activity of 3.18 mA cm 2 which are 10 times and 12 times higher than commercial Pt/C catalysts, respectively. In addition, the 1D nanostructure enables the catalyst to be highly stable after 30 000 potential sweeping cycles. This work successfully extends bulky high indexed Pt alloys to core shell nanostructures with the design of a new, highly efficient and stable Pt based catalyst for fuel cells.
author_names: Yueping Zhao

Lu Tao

Wei Dang

Linlin Wang

Meirong Xia

Bo Wang

Minmin Liu

Faming Gao

Jiujun Zhang

Yufeng Zhao
title: High Indexed PtNi Alloy Skin Spiraled on Pd Nanowires for Highly Efficient Oxygen Reduction Reaction Catalysis.
venue: Small
year: 2019

abstract: Abstract Novel enzyme mimic materials with excellent analytical properties and stable structure are essential for detecting H2O2 in many fields. In the present work, we prepare PtNi alloy/CeO2 plates/N doped carbon nanofibers (PtNi/CeO2/NCNFs) via heat treating the electrospun nanofiber hybrid of polyvinyl pyrrolidone and inorganic metal salts. Structural analysis indicate that PtNi alloy nanoparticles disperse on or around CeO2 nanoplates and PtNi alloy/CeO2 plates uniformly embed in porous NCNFs. A possible formation mechanism of PtNi alloy/CeO2 plates in NCNFs is put forward based on the electrostatic interaction of Ce3+ P t C l 6 2 and Ni2+ The special structure of PtNi/CeO2/NCNFs can initiate the synergistic effect and enhance its enzyme like electrocatalytic activity toward the reduction of H2O2. The PtNi/CeO2/NCNFs based sensor displays outstanding performances for H2O2 detection with wide linear range of 0.5 mM 15 mM, high sensitivity of 345.0 mA mM 1 cm 2, low detection limit of 0.025 mM, high selectivity and anti interference. Besides, the sensor possesses superior reproducibility and good stability. The RSD value of response current obtained from five parallel experiments is evaluated to be 2.36% and PtNi/CeO2/NCNFs GCE can still remain 98.5% of the initial response current value after being stored at 25 degC for 15 days. More importantly, the constructed sensor can be applied to detection of H2O2 content in cosmetics with satisfactory recovery (95.8% 103.8% and low relative standard deviation 4.5% These attractive properties make it possible for PtNi/CeO2/NCNFs to analyze H2O2 in real samples.
author_names: Huijuan Guan

Jun Zhang

Yong-zhi Liu

Yafei Zhao

Bing Zhang
title: Rapid quantitative determination of hydrogen peroxide using an electrochemical sensor based on PtNi alloy/CeO2 plates embedded in N doped carbon nanofibers
venue: Electrochimica Acta
year: 2019

abstract: Abstract During the past few decades, substantial efforts have been made to explore high performance electrocatalysts for proton exchange membrane fuel cells due to the sluggish oxygen reduction reaction kinetics at the cathode. Among multifarious approaches, it has been demonstrated that alloying Pt nanocrystals with transition metals and introducing Pt based nanocrystals with high index facets have been recognized as effective strategies to facilitate the enhancement of oxygen reduction reaction performance. However, the current synthetic approach for preparing catalysts with high index facets is complicated. Herein, we demonstrate a straightforward one step method to synthesize three dimensional flower like high index faceted PtNi alloy nanocrystals constituted by abundant nano cones similar to the quadrihedron. The as prepared catalyst exhibits remarkably improved catalytic performance in comparison with PtNi 1, PtNi 2 and Pt/C, which is ascribed to a great number of high index facets and highly open hierarchical structure. The resultant high index faceted PtNi alloy nanocrystals deliver excellent mass activity of 1.76 A mg 1. Meanwhile, the material also displays a great stability after 20000 potential cycles. Consequently, the methodology proposed in this work may provide some guidance to boost the improvement of oxygen reduction reaction, and the 3D flower like high index faceted PtNi alloy nanocrystals have a great potential to be turned into effective cathode catalysts for proton exchange membrane fuel cells.
author_names: Shili You

Pan Luo

Ling Fang

Jiaojiao Gao

Li Liu

Haitao Xu

Huijuan Zhang

Yu Wang
title: Unique hierarchical flower like PtNi alloy nanocrystals with enhanced oxygen reduction properties
year: 2019

abstract: Abstract The development of the fuel cell catalysts with high durability and high activity for oxygen reaction reduction remains a great challenge. Various material designs such as alloys, core@shell structure and shape control provide the promising ways to improve the electrocatalytic performance. Herein, on the basis of both the alloy effect and the nanotube structure effect, we demonstrate a high performance PtNi alloy catalyst with one dimensional nanotube structure via a galvanic replacement reaction combined with Kirkendall effect. Meanwhile, the PtNi alloy phase and the tube structure are selectively controlled by tuning the PtNi atomic ratio and the wall thickness of the nanotube, respectively. Subsequently, the understanding of the composition effect and the shape effect on the activity and the durability is systematically investigated. The optimized PtNi nanotube catalyst shows significant improvements on the activity (6.2 fold increase in specific activity compared to the commercial Pt/C) and the durability (only 8.6% loss in mass activity after 10000 cycles) attributing to the alloy effect by introducing Ni to the Pt lattice, the Pt rich surface and the shape effect of the unique one dimensional hollow tube structure.
author_names: Chuanting Fan

Guoliang Wang

Liangliang Zou

Jian-hui Fang

Zhiqing Zou

Honbo Yang
title: Composition and shape controlled synthesis of the PtNi alloy nanotubes with enhanced activity and durability toward oxygen reduction reaction
venue: Journal of Power Sources
year: 2019

abstract: Graphite carbon nitride (g C3N4) supported PtNi alloy nanoparticles (NPs) were fabricated via a facile and simple impregnation and chemical reduction method and explored their catalytic performance towards hydrogen evolution from ammonia borane (AB) Interestingly, the resultant Pt0.5Ni0.5/g C3N4 catalyst affords superior performance, including 100% conversion, 100% H2 selectivity, yielding the extraordinary initial total turnover frequency (TOF) of 250.8 molH2 min 1 (molPt) 1 for hydrogen evolution from AB at 10 degC, a relatively low activation energy of 38.09 kJ mol 1, and a remarkable reusability (at least 10 times) which surpass most of the noble metal heterogeneous catalysts. This notably improved activity is attributed to the charge interaction between PtNi NPs and g C3N4 support. Especially, the nitrogen containing functional groups on g C3N4, serving as the anchoring sites for PtNi NPs, may be beneficial for becoming a uniform distribution and decreasing the particle size for the NPs. Our work not only provides a cost effective route for constructing high performance catalysts towards the hydrogen evolution of AB but also prompts the utilization of g C3N4 in energy fields.
author_names: Mingya Zhang

Yun Wu

Yue An

Lixin Xu

Chao Wan
title: Hydrogenation Production from Ammonia Borane over PtNi Alloy Nanoparticles Immobilized on Graphite Carbon Nitride
year: 2019

abstract: AbstractMonodisperse stone like PtNi alloy nanoparticles (NPs) were synthesized at room temperature using an inverse microemulsion method. The results of XRD, HRTEM, and EDS demonstrate that these NPs consist of a disordered alloy that has (a) a face centered cubic structure, (b) Pt/Ni atomic ratios of ~5:1, and (c) a large number of atoms exposed on the NP surface and enclosed by low index facets. The material was placed on a glassy electrode which then displayed superior response to glucose. Best operated at a potential of 0.43 V (vs. SCE) the electrode has the following features: (a) a wide linear range (from 0.5 mM to 40 mM) (b) rapid response <1 s) (c) a low detection limit (0.35 mM) and (d) a sensitivity of 40.17 mA mM 1cm 2) The NP sensor also is fairly selective over ascorbic acid, uric acid and fructose. The sensor has repeatability and durability for up to 30 days after manufacture. Graphical abstractNon enzymatic glucose sensor based on a glassy carbon electrode modified with PtNi NPS enclosed by low index facets. The sensor exhibits excellent features towards detecting glucose.
author_names: Rulei Wang

Xinyi Liang

Haiyan Liu

Lan Cui

Xiaoyue Zhang

Changjiang Liu
title: Non enzymatic electrochemical glucose sensor based on monodispersed stone like PtNi alloy nanoparticles
venue: Microchimica Acta
year: 2018

abstract: AbstractAn economic and effective Pt based alloy cocatalyst has attracted considerable attention due to their excellent catalytic activity and reducing Pt usage. In this study, PtNi alloy cocatalyst was successfully decorated on the g C3N4/GO hybrid photocatalyst via a facile chemical reduction method. The Eosin Y sensitized g C3N4/PtNi/GO 0.5% composite photocatalyst yields about 1.54 and 1178 times higher hydrogen evolution rate than the Eosin Y sensitized g C3N4/Pt/GO 0.5% and g C3N4/Ni/GO 0.5% samples, respectively. Mechanism of enhanced performance for the g C3N4/PtNi/GO composite was also investigated by different characterization, such as photoluminescence, transient photocurrent response, and TEM. These results indicated that enhanced charge separation efficiency and more reactive sites are responsible for the improved hydrogen evolution performance due to the positive synergetic effect between Pt and Ni. This study suggests that PtNi alloy can be used as an economic and effective cocatalyst for hydrogen evolution reaction. Graphical abstractA significant enhancement of photocatalytic H2 evolution is realized over the Eosin Y sensitized g C3N4/PtNi/GO composite with PtNi alloy as an efficient cocatalyst.
author_names: Peng Wang

Lanlan Zong

Zhongjie Guan

Qiuye Li

Jianjun Yang
title: PtNi Alloy Cocatalyst Modification of Eosin Y Sensitized g C3N4/GO Hybrid for Efficient Visible Light Photocatalytic Hydrogen Evolution
venue: Nanoscale Research Letters
year: 2018