Nanoscale
·
2014
·Vol. 6
·期 11
·6173-6179
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IF 6.739
Yan Feng,Xiaohong Ma,Lin Han,Zhijian Peng,Jun Yang
Nanomaterials usually exhibit structure-dependent catalytic activity, selectivity, and stability. Herein, we report a universal approach for the synthesis of noble metal nanoparticles with a dendritic structure, which is based on the reduction of metal acetylacetonate precursors in oleylamine at a temperature of 160 °C. In this strategy, the metal acetylacetonate precursors are reduced into metal atoms by oleylamine and grow into metal nanoparticles, while oleylamine is simultaneously converted into oleylamide to protect the nanoparticles. The competition between particle aggregation and oleylamide passivation is essential to the formation of a large number of particle aggregates, which eventually grow into nanodendrites via Ostwald ripening process. In particular, in comparison with commercial PtRu/C catalysts, the alloy PtRuOs nanodendrites exhibited superior catalytic activity toward methanol oxidation.
研究领域:
材料科学
·
化学工程
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2021
·
IF 8.271
Yuxiang Liao,Jun Li,Shiming Zhang,Shengli Chen
Alloying and nanostructuring are two strategies used to facilitate the efficient electrocatalysis of the oxygen reduction reaction (ORR) by Pt, where the high index surfaces (HISs) of Pt exhibit superior activity for ORR. Here, we report the fabrication of PtCu 3 nanodendrites possessing rich spiny branches exposing n (111) × (110) HISs. The dendrites were formed through an etching-modulated seeding and growing strategy. Specifically, an oxidative atmosphere was initially applied to form the concaved nanocubes of the Pt-Cu seeds, which was then switched to an inert atmosphere to promote an explosive growth of dendrites. Separately, the oxidative or inert atmosphere failed to produce this hyperbranched structure. Electrochemical dealloying of the PtCu 3 nanodendrites produced Pt 3 Cu shells with Pt-rich surfaces where HIS-exposed dendrite structures were maintained. The resulting PtCu 3 @Pt 3 Cu@Pt nanodendrites in 0.1 M HClO 4 exhibited excellent mass and area specific activities for ORR, which were 14 and 24 times higher than that of commercial Pt/C, respectively. DFT calculations revealed that Cu alloying and HISs both contributed to the significantly enhanced activity of Pt, and that the oxygen binding energy on the step sites of HISs on the PtCu 3 @Pt 3 Cu@Pt nanodendrites approached the optimal value to achieve a near peak-top ORR activity.
研究领域:
材料科学
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电化学
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DOI
高影响因子
NANOTECHNOLOGY
·
2019
·Vol. 31
·期 1
·015502
·
IF 3.399
Jiawang Guo,Yuan Lin,Qian Wang
We developed a facile method to fabricate platinum (Pt) porous nanotubes coated with interconnected Pt dendrites using the tobacco mosaic virus (TMV) as a template. The surface-exposed arginine residues of the TMV induced the selective deposition of Pt seeds on the TMV outside surface, and poly(sodium-p-styrenesulfonate) (PSS) was chosen to stabilize the dispersity of TMV coated with Pt seeds (TMV/SPt). The limited space between the Pt seeds and their uniform distribution on the TMV exterior confined the growth of Pt dendrites, resulting in continuous dendritic platinum nanotubes (TMV/DPtNT). The synergistic effects of porous dendrites and anisotropic structures of the TMV/DPtNTs provided an increase in the active sites, the enhancement of transport efficiency and long-distance electron transfer, which greatly improved the catalytic activity. We also demonstrated that such nanotubes could be used in the detection of H2O2 with good sensitivity.
研究领域:
材料科学
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生物纳米技术
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化学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2020
·
IF 7.632
Kaisheng Yao,Tianjin Li,Chenchen Zhao,Weiwei Lu,Shuang Zhao,Jianji Wang
Conceiving a simple, green, and mild one-pot route to grow and construct anisotropic bimetallic 3D architectures with multilevel structures and promising functions is highly desirable and technically important in many applications. Herein, a facile ionic liquid-modulated strategy is presented for the preparation of hyperbranched Au3Pd1 bimetallic nanodendrites (NDs) in aqueous solution at room temperature. To implement this protocol, HAuCl4 and Na2PdCl4 are used as precursors and ascorbic acid as a reductant, and a common ionic liquid 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) is utilized to direct the anisotropic growth of 3D Au3Pd1 NDs, which exhibits an eco-friendly feature. It is shown that the alloy Au3Pd1 NDs possess multilevel architectures, that is, primary 3D large flowers (with diameters of about 2.5–4.0 μm), secondary 2D leaves, tertiary symmetric branches, and quaternary symmetric petals. A series of factors influencing morphologies and properties of the products are investigated, and the results indicate that both [C4mim]Cl and Au/Pd atomic ratios are crucial to the formation of 3D Au3Pd1 NDs. Owing to the well-defined morphology and probable electronic effects between Au and Pd, the 3D Au3Pd1 NDs display high catalytic selectivity and good durability toward stepwise hydrogenation of 4-nitrophenylacetylene with a 100% conversion and 99.5% selectivity to 4-nitrostyrene in the first step and then 100% conversion from 4-nitrostyrene and 96.7% selectivity to 4-nitroethylbenzene in the second step. It is believed that the well-defined 3D Au3Pd1 NDs would also exhibit promising applications in other catalysis and eletrocatalysis applications.
研究领域:
材料科学
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催化化学
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环境科学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
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2017
·
IF 2.594
Yanrong Ma,Tongfei Li,Hao Chen,Xiaojie Chen,Sihui Deng,Lin Xu,Dongmei Sun,Yawen Tang
Rational synthesis of a new class of electrocatalysts with high-performance and low-cost is of great significance for future fuel cell devices. Herein, we demonstrate a general one-step simultaneous reduction method to prepare carbon-supported PdM (M = Co, Fe, Ni) alloyed nanodendrites with the assistance of oleylamine and octadecylene. The morphology, structure and composition of the obtained PdM nanodendrites/C catalysts have been fully characterized. The combination of the dendritic structural feature and alloyed synergy offer higher atomic utilization efficiency, excellent catalytic activity and enhanced stability for the formic acid oxidation reaction (FAOR). Strikingly, the as-synthesized PdCo nanodendrites/C catalyst could afford a mass current density of 2467.7 A g −1 , which is almost 3.53 and 10.4 times higher than those of lab-made Pd/C sample (698.3 A g −1 ) and commercial Pd/C catalyst (237.6 A g −1 ), respectively. Furthermore, the PdCo nanodendrites/C catalyst also exhibit superior stability relative to the Pd/C catalysts, make it a promising anodic electrocatalyst in practical fuel cells in the future. Additionally, the present feasible synthetic approach is anticipated to provide a versatile strategy toward the preparation of other metal alloy nanodendrites/carbon nanohybrids .
研究领域:
材料科学
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电化学
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能源科学
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产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
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2020
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IF 0
Jian Huang,Zhe Lei,Qian Zhang,Mei Juan Su,Liang Liu
Highly active Al-based Ag dendrites SERS plasmonic substrates have been rapidly synthesized by the one-step galvanic displacement reaction without the use of any surfactants and templates. The as-prepared SERS substrates were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. XRD measurements confirmed the metallic nature of the formed Ag dendrites. None of the organic additives were used in the synthesis process, which ensures the substrates surfaces are completely clean and avoiding the introduction of organic contaminants. The innovative rough bionic substrates yield a final silver dendritic structure that offers large specific surface area and high-density hotspots. Using malachite green as a model target, the Al-based Ag dendrites SERS substrates exhibited acceptable reproducibility (relative standard deviation of 23.8%) and high enhancement capacities (pushed the detection limit down to 10 pM). Importantly, these Ag dendrites could potentially be employed as highly active and cost effective flexible SERS sensors for label-free ultrasensitive detection of biomolecules.
研究领域:
材料科学
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分析化学
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DOI
ACS Applied Materials & Interfaces
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2018
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IF 8.097
Juan Bai,Xue Xiao,Yuan-Yuan Xue,Jia-Xing Jiang,Jing-Hui Zeng,Xi-Fei Li,Yu Chen
Rationally designing and manipulating composition and morphology of precious metal-based bimetallic nanostructures can markedly enhance their electrocatalytic performance, including selectivity, activity, and durability. We herein report the synthesis of bimetallic PtRh alloy nanodendrites (ANDs) with tunable composition by a facile complex-reduction synthetic method under hydrothermal conditions. The structural/morphologic features, formation mechanism, and electrocatalytic performance of PtRh ANDs are investigated thoroughly by various physical characterization and electrochemical methods. The preformed Rh crystal nuclei effectively catalyze the reduction of Pt2+ precursor, resulting in PtRh alloy generation due to the catalytic growth and atoms interdiffusion process. The Pt atoms deposition distinctly interferes in Rh atoms deposition on Rh crystal nuclei, resulting in dendritic morphology of PtRh ANDs. For the ethanol oxidation reaction (EOR), PtRh ANDs display the chemical composition and solution pH co-dependent electrocatalytic activity. Because of the alloy effect and particular morphologic feature, Pt1Rh1 ANDs with optimized composition exhibit better reactivity and stability for the EOR than commercial Pt nanocrystals electrocatalyst.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 12
·4384-4390
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IF 0
Jing-Jing Lv,Jie-Ning Zheng,Shan-Shan Li,Li-Li Chen,Ai-Jun Wang,Jiu-Ju Feng
In this report, well-dispersed porous Pt–Pd nanodendrites (Pt–Pd NDs) were synthesized at high yield by a simple, one-pot, wet chemical method without using any seed, template, or toxic organic solvent. Poly(vinylpyrrolidone) (PVP) and urea were employed as the co-stabilizing and co-structure-directing agents. It was found that the reaction temperature, the amount of PVP and urea, the Pt/Pd molar ratio, and the pH value of the reaction media greatly affected the size and shape of the Pt–Pd product. The as-prepared Pt–Pd nanocrystals had a larger active surface area, superior catalytic activity, and better stability for the electrooxidation of methanol and ethylene glycol (EG), compared with the commercial Pt-black and Pd-black catalysts.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
ANALYST
·
2013
·Vol. 138
·期 9
·2598-2603
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IF 3.969
Yongchao Lai,Jingcheng Cui,Xiaohong Jiang,Sha Zhu,Jinhua Zhan
A surface-enhanced Raman spectroscopy (SERS)-active extraction column based on propanethiol modified silver dendrites was fabricated. The column, which combines the advantages of solid phase extraction and SERS, may facilitate the development of rapid analysis with high reliability and accuracy. High temporal stability (under a continuous and intensive laser radiation) and excellent repeatability (repeated extraction and elution) were also achieved using this column. As an example, the quantitative analysis of fluoranthene was accomplished in the concentration range of 0.01–100 μg mL−1 with this column. The extraction process could be accomplished in 10 s and the total time of one sample analysis including extraction, spectral acquisition, elution and intermediate process could be less than 30 s. This method can greatly simplify the sample preparation and reduce the total analysis time.
研究领域:
分析化学
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环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Chen Chen,Xianzhuo Lao,Yu Zhao,Mang Niu,Peizhi Guo
Designing economical and efficient nanocatalysts to enhance the efficiency and commercialization potential of direct ethanol fuel cells (DEFCs) is a challenging task. In the present study, we have crafted PdAg spatial nanodendrites (NDs) featuring distinct morphologies and precise compositional control, employing a streamlined one-step solvothermal approach. Modulating the molar quantity of the AgNO3 precursor can substantially modify the morphology and alloy composition of PdAg nanodendrites. The addition of Ag to the PdAg NDs resulted in lattice expansion, causing a shift in the d-band center of Pd. In addition, the porous nature of PdAg NDs provides numerous active sites for catalytic reactions, significantly enhancing the activity and stability of the ethanol oxidation reaction (EOR). It is important to note that the PdAg NDs exhibit “volcano” characteristics. Among these, the Pd9Ag1 NDs demonstrate excellent electrocatalytic activity and outstanding stability. It has been found to have an electrocatalytic activity of 2450 mA mgpd–1 for ethanol oxidation. This study offers a solution for the preparation of catalysts for fuel cells and motivates the creation of innovative structures to improve electrocatalytic activities.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Yuanxin Du,Kun Ni,Qingxi Zhai,Yapei Yun,Yajie Xu,Hongting Sheng,Yanwu Zhu,Manzhou Zhu
In this work, we utilized a facile air oxidative dealloying approach to synthesize PtCu hierarchical branched nanodendrites (HBNDs). The systematical investigation on the morphology, composition, and structure of PtCu HBNDs by various techniques demonstrates they are three-dimensional open porous nanostructures. The PtCu HBNDs show composition-dependent catalysis in hydrogen evolution reaction (HER). The Pt 1 Cu 1.03 -D with average size about 40 nm composed of integrated ultrathin branches, presents the highest HER activity with only 20 mV overpotential to achieve 10 mA/cm 2 , 19.34 A/mg Pt and 9.64 mA/cm 2 in mass and specific activity at −0.2 V, and excellent durability. The superior HER activity is attributed to the unique porous dendritic structure and electronic synergistic interactions between Pt and Cu as indicated by X-ray photoelectron spectroscopy and density functional theory calculation. This work opens up a new facile route to design large accessible surface and high-performance electrocatalysts with low utilization of Pt for electrochemical energy conversion.
研究领域:
材料科学
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电化学
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能源转换
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）