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Noble metal

Nicolas Kaeffer, Christopher D Windle, Romain Brisse, Corinne Gablin, Didier Leonard, Bruno Jousselme, Murielle Chavarot-Kerlidou, Vincent Artero
Dye-sensitized photo-electrochemical cells (DS-PECs) form an emerging technology for the large-scale storage of solar energy in the form of (solar) fuels because of the low cost and ease of processing of their constitutive photoelectrode materials. Preparing such molecular photocathodes requires a well-controlled co-immobilization of molecular dyes and catalysts onto transparent semiconducting materials. Here we used a series of surface analysis techniques to describe the molecular assembly of a push-pull organic dye and a cobalt diimine-dioxime catalyst co-grafted on a p-type NiO electrode substrate...
August 28, 2018: Chemical Science
Xiaolong Liu, Li Chen, Tingyu Zhu, Ruliang Ning
Catalytic oxidation of chlorobenzene over noble metal catalysts Pd/TiO2 , Pt/TiO2 , Ru/TiO2 , and Rh/TiO2 was evaluated, and Ru/TiO2 contributed the highest catalytic activity and CO2 selectivity. During the oxidation, polychlorinated benzenes PhClx (x ≥ 2) were observed, and Ru/TiO2 showed apparently lower PhClx concentrations than other three samples. With the improvement of temperature, the maximum concentration appeared in the sequence of dichlorobenzene (PhCl2 ), trichlorobenzene (PhCl3 ), tetrachlorobenzene (PhCl4 ), and pentchlorobenzene (PhCl5 ), whereas the concentration of hexachlorobenzene (PhCl6 ) was always low and showed no apparent regularity...
October 3, 2018: Journal of Hazardous Materials
Pengping Xu, Huihui Wu, Dongdong Wang, Gaozheng Zhao, Fenfen Li, Bensheng Qiu, Zhen Guo, Qianwang Chen
Multifunctional theranostic nanoagents which realize precise diagnosis and treatment of tumors are attracting increasing interests in recent years. However, efficient and controlled synthesis of ultra-small noble metal nanoagents remains a challenge. Here, monodisperse Gd/Ru@BSA nanodots (GRBNDs) are successfully fabricated via a totally "green", "one-pot" protocol for in situ reduction of Ru(III) and biomineralization of Gd(III) in the presence of albumin. The as-prepared nanoagent possesses the features of being ultra small in size (≈6...
October 2018: Advanced Healthcare Materials
Xu Liu, Lei Wang, Peng Yu, Chungui Tian, Fanfei Sun, Jingyuan Ma, Wei Li, Honggang Fu
Developing low-cost and high-efficient bifunctional ORR/OER electrocatalyst, featured by binary active sites, excellent transfer for oxygen-relevant species and electrons, is still challenging for Zn-air batteries. Herein, we have designed a 3D catalyst composed of CoFe alloy nanoparticles embedded in N-doped bamboo-like CNTs tangled with RGO, which has above features and exhibits well ORR/OER bifunctional activity. Specially, a fabricated liquid Zn-air battery could deliver a high open-circuit voltage of 1...
October 10, 2018: Angewandte Chemie
Yi Li, Yazhou Zhou, Hejing Wen, Juan Yang, Chanez Maouche, Qinqin Liu, Yunyan Wu, Chao Cheng, Jia Zhu, Xiaonong Cheng
The intrinsic instability and difficulty in controlling the uniform size distributions of cobalt sulfides greatly restrict their application for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) as a bifunctional electrocatalyst in regenerative fuel cells and rechargeable metal-air batteries. Herein, we synthesize a stable electrocatalyst of N,S-atom-coordinated Co9S8 trinary dopants within a porous graphene framework (Co9S8@NS-3DrGO), in which Co9S8 nanoparticles show uniform sizes and distributions...
October 10, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Geng-Geng Luo, Zhong-Hua Pan, Jin-Qing Lin, Di Sun
Inspired by natural photosynthesis in an organized assembly, compact H2-evolving molecular devices, which tether sensitizer and catalyst modules in one single molecule, present an opportunity to overcome the diffusion limit required for multi-component molecular systems, and increase intramolecular electron transfer rates from the photoactivated unit to the catalytic center to improve H2-evolving efficiency. Thereinto absolutely noble-metal free H2-evolving molecular devices are of particular interest because they don't contain precious and scarce noble-metal based components...
October 9, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Martin Kluenker, Bethany M Connolly, David M Marolf, Muhammad Nawaz Tahir, Karsten Korschelt, Paul Simon, Uta Köhler, Sergi Plana-Ruiz, Bastian Barton, Martin Panthöfer, Ute Kolb, Wolfgang Tremel
Controlling the morphology of noble-metal nanoparticles is mandatory to tune specific properties such as catalytic and optical behavior. Heterodimers consisting of two noble metals have been synthesized, so far mostly in aqueous media using selective surfactants or chemical etching strategies. We report a facile synthesis for Au@Pd and Pd@Au heterodimer nanoparticles (NPs) with morphologies ranging from segregated domains (heteroparticles) to core-shell structures by applying a seed-mediated growth process with Au and Pd seed nanoparticles in 1-octadecene (ODE), which is a high-boiling organic solvent...
October 5, 2018: Inorganic Chemistry
Yan-Xia Zhao, Zi-Yu Li, Yuan Yang, Sheng-Gui He
The increasing supply of natural gas has created a strong demand for developing efficient catalytic processes to upgrade methane, the most stable alkane molecule, into value-added chemicals. Currently, methane conversion in laboratory and industry is mostly performed under high-temperature conditions. A lot of effort has been devoted to exploring chemical entities that are able to activate the C-H bond of methane at lower temperatures, preferably room temperature. Gas phase atomic clusters with limited numbers of atoms are ideal models of active sites on heterogeneous catalysts...
October 5, 2018: Accounts of Chemical Research
Shijian Zhou, Weiming Jin, Yun Ding, Bo Shao, Bangbang Wang, Xu Hu, Yan Kong
Nowadays, agglomeration and leaching of metal active sites during reaction and recycle processes are considered to be a thorny problem for noble metal-based catalysts. Therefore, to make improvements, nano-gold was selected as a representative research object for many noble metals. In this study, Au nanoparticles (NPs) and magnetic γ-Fe2O3 were intercalated in situ in the walls of MCM-41 via a one-pot hydrothermal method, in which the intercalation process was preceded by co-condensation of tetraethyl orthosilicate (TEOS) with MPTS-Au complexes ((3-mercaptopropyl)-trimethoxysilane (MPTS), HAuCl4·3H2O), and a Fe3O4 sol...
October 5, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Jing Du, Lixin Wang, Lei Bai, Shijia Dang, Li Su, Xiujuan Qin, Guangjie Shao
Development of highly-active and noble-metal-free electrocatalysts for hydrogen evolution reactions is a challenge, and optimizing the structure and the composition of the relative materials is critical to obtain the high-quality catalysts. Ni-based compounds are being explored as noble-metal-free electrocatalysts in hydrogen evolution reactions but the Ni-based needs to be modified effectively. In this work, we co-electrodeposited Ni nanoparticles, hydrophilic graphene and graphene oxide layers on Ni foam to synthesize Ni-HG-rGO/NF catalysts...
September 25, 2018: Journal of Colloid and Interface Science
Zhongcheng Li, Mengmin Xiao, Ying Zhou, Deliang Zhang, Hongzhen Wang, Xien Liu, Debao Wang, Wenpin Wang
Exploration and fabrication of low-cost but highly active electrocatalysts, alternatives to noble metals, have remained a challenge for overall water splitting reaction. To date, few studies have reported that the Earth-abundant pyrite FeS2 is catalytically active for hydrogen evolution reaction, while there is no study on the oxygen evolution reaction and overall water splitting reaction using pyrite FeS2 as an electrocatalyst. Here, we offer a facile hydrothermal approach for the synthesis of FeS2 nanoparticles by the reduction of FeCl3·6H2O with C5H10NS2Na·3H2O...
October 3, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Tao Song, Yong Yang
Heteroatom-doped porous carbon derived from biomass have recently received increasing attention due to their unique properties such as high electrical conductivity, large specific surface area, high porosity, and easy availability, which are appealing materials for versatile applications in catalysis, energy, separation and adsorption, and life sciences as well. On the basis of our previous work in this field, we summarized in this account our recent progress on design, synthesis of metal (e. g., Pd, Co) nanoparticles supported heteroatom-doped hierarchical porous carbon material derived from bamboo shoots and their applications for important organic transformations, including chemoselective semihydrogenation of alkynes, hydrosilylation of alkynes, cascade synthesis of benzofurans from terminal alkynes and iodophenols, selective hydrogenation of functionalized nitroarenes to form anilines, imines, and formamides...
October 1, 2018: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Nicoleta Anca Sutan, Denisa Stefania Manolescu, Irina Fierascu, Angela Monica Neblea, Claudiu Sutan, Catalin Ducu, Liliana Cristina Soare, Denis Negrea, Sorin Marius Avramescu, Radu Claudiu Fierascu
Extracts obtained from different plant species proved to be a valuable tool in various biomedical applications. In the same time, the phytosynthesis of noble metal nanoparticles represents an already well-established route for obtaining nanoparticles with biological activity. The present paper studies the antioxidant activity and the cytogenetic effects of the alcoholic extracts from rhizomes of Aconitum toxicum Rchb., before and after the phytosynthesis of gold and silver nanoparticles, on the meristematic root cells of Allium cepa L...
December 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Bálint Fridrich, Marc C A Stuart, Katalin Barta
Fermentation of sugars to the so-called ABE mixture delivers a three component mixture of shorter chain oxygenates: acetone, n -butanol and ethanol. In order to convert these into liquid transportation fuels that are analogous to the currently used fossil energy carriers, novel catalytic chain elongation methods involving C-C bond formation are desired. Herein we report on a simple, non-noble-metal-based method for the highly selective coupling of 1-butanol and acetone into high molecular weight (C7-C11) ketones, as well as ABE mixtures into (C5-C11) ketones using the solid base Mg-Al-PMO in combination with small amount of Raney nickel...
July 2, 2018: ACS Sustainable Chemistry & Engineering
Dong Xiang, Xiangjie Bo, Xiaohui Gao, Cheng Du, Ping Li, Liande Zhu, Wei Chen
Nonprecious-metal electrocatalysts have been intensively investigated, but how to keep a balance between their sustainability and competitive performance for the oxygen reduction reaction (ORR) is still a big challenge for energy applications. In this work, a type of bimetal- and nitrogen-codoped mesoporous carbon electrocatalyst (FeCo-N/C-800) was successfully synthesized via a simple hydrothermal method, followed by a calcination process at 800 °C in nitrogen atmosphere and an acid-etching process. The obtained FeCo-N/C-800 can act as a high-performance ORR catalyst with high onset and half-wave potentials (0...
September 19, 2018: Journal of Colloid and Interface Science
Stefan-Adrian Strungaru, Gabriel Plavan, Alin Ciobica, Mircea Nicoara, Madalina Andreea Robea, Carmen Solcan, Elena Todirascu-Ciornea, Adriana Petrovici
Gold is a noble metal having a long history of human usage and a variety of applications. The present paper was designed in order to see the changes on social and swimming behavior of zebrafish caused by acute gold exposure to high concentrations dissolved in aquatic medium from a standard solution with the highest purity. Some main oxidative stress markers were determined such as: superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and glutathione peroxidase (GPx). We also focused our attention on the bioaccumulation capacity of gold in exposed zebrafish and its competition with essential elements for the body: sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn) and copper (Cu)...
December 2018: Journal of Trace Elements in Medicine and Biology
Jianxun Liu, Huilin He, Dong Xiao, Shengtao Yin, Wei Ji, Shouzhen Jiang, Dan Luo, Bing Wang, Yanjun Liu
In the past half-century, surface plasmon resonance in noble metallic nanoparticles has been an important research subject. Recent advances in the synthesis, assembly, characterization, and theories of traditional and non-traditional metal nanostructures open a new pathway to the kaleidoscopic applications of plasmonics. However, accurate and precise models of plasmon resonance are still challenging, as its characteristics can be affected by multiple factors. We herein summarize the recent advances of plasmonic nanoparticles and their applications, particularly regarding the fundamentals and applications of surface plasmon resonance (SPR) in Au nanoparticles, plasmon-enhanced upconversion luminescence, and plasmonic chiral metasurfaces...
September 26, 2018: Materials
Changhong Wang, Yun Wang, Hongchao Yang, Yejun Zhang, Huijun Zhao, Qiangbin Wang
Establishing a correlation between the crystal structure and electrocatalytic activity is crucial to the rational design of high performance electrocatalysts. In this work, taking the widely investigated nickel (Ni) based nonprecious oxygen evolution reaction (OER) catalyst as an example, for the first time, it is reported that the crystal structure plays a critical role in determining the OER performance. Similar-sized nickel nanoparticles but in different hexagonal close-packed phase and face-centered cubic phase coated with N-doped carbon shells, noted as hcp-Ni@NC and fcc-Ni@NC, are successfully prepared, respectively, in which the N-coated carbon shell structures were also similar...
October 2018: Small
Zicheng Zuo, Dan Wang, Jin Zhang, Fushen Lu, Yuliang Li
The development of carbon materials offers the hope for obtaining inexpensive and high-performance alternatives to substitute noble-metal catalysts for their sustainable application. Graphdiyne, the rising-star carbon allotrope, is a big family with many members, and first realized the coexistence of sp- and sp2 -hybridized carbon atoms in a 2D planar structure. Different from the prevailing carbon materials, its nonuniform distribution in the electronic structure and wide tunability in bandgap show many possibilities and special inspirations to construct new-concept metal-free catalysts, and provide many opportunities for achieving a catalytic activity comparable with that of noble-metal catalysts...
September 27, 2018: Advanced Materials
Guojun Han, Matthew H Spitzer, Sean C Bendall, Wendy J Fantl, Garry P Nolan
Advances in single-cell mass cytometry have increasingly improved highly multidimensional characterization of immune cell heterogeneity. The immunoassay multiplexing capacity relies on monoclonal antibodies labeled with stable heavy-metal isotopes. To date, a variety of rare-earth elements and noble and post-transition metal isotopes have been used in mass cytometry; nevertheless, the methods used for antibody conjugation differ because of the individual metal coordination chemistries and distinct stabilities of various metal cations...
October 2018: Nature Protocols
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