Read by QxMD icon Read

carbon doping

Ajit Khosla, Shreyas Shah, M D Nahin Islam Shiblee, Sajjad Husain Mir, Larry Akio Nagahara, Thomas Thundat, Praveen Kumar Shekar, Masaru Kawakami, Hidemitsu Furukawa
We have developed conductive microstructures using micropatternable and conductive hybrid nanocomposite polymer. In this method carbon fibers (CFs) were blended into polydimethylsiloxane (PDMS). Electrical conductivities of different compositions were investigated with various fiber lengths (50-250 μm), and weight percentages (wt%) (10-60 wt%). Sample composites of 2 cm × 1 cm × 500 μm were fabricated for 4-point probe conductivity measurements. The measured percolation thresholds varied with length of the fibers: 50 wt% (307...
August 17, 2018: Scientific Reports
Soliu O Ganiyu, Elisama Vieira Dos Santos, Emily Cintia Tossi de Araújo Costa, Carlos A Martínez-Huitle
Electrochemical advanced oxidation processes such as electrooxidation (EO), electrooxidation with hydrogen peroxide generation (EO-H2 O2 ) and electro-Fenton process (EF) have been investigated as alternative treatment techniques for complete removal of anionic surfactants and organic matters from real carwash wastewater. The electrochemical processes were performed with acidified real carwash wastewater using boron doped anode and carbon felt cathode. In all cases, the chemical oxygen demand (COD) removal efficiency was always increased with rise in applied current and complete organic matter decay was achieved at applied current of 500 mA or above after 6 h of electrolysis...
August 11, 2018: Chemosphere
Hengpan Yang, Hanwen Zhang, Yu Wu, Liangdong Fan, XiaoYan Chai, QianLing Zhang, Jianhong Liu, Chuanxin He
Numerous catalysts have been successfully introduced into CO2 fixation in aqueous or organic systems. However, one single catalyst owning both activities is still rarely seen, to the best of our knowledge. In this report, we develop a core-shell structured AgNWs/NC700 composite using Ag nanowires core encapsulated by nitrogen-doped carbon shell. Through contrast experiments and DFT calculations, it was confirmed that Ag nanowires worked as the active sites for CO2 fixation and the uniformly coating of nitrogen-doped carbon created a CO2-rich environment around Ag nanowires, which could significantly improve the catalytic activity of Ag nanowires for electrochemical CO2 fixation...
August 17, 2018: ChemSusChem
Ewelina Bolimowska, Franca Castiglione, Julien Devemy, Hélène Rouault, Andrea Mele, Agilio A H Padua, Catherine C Santini
To increase the safety and stability of Lithium ion batteries, the development of electrolytes based on ionic liquids gained a lot of attention in recent years. However, with graphite electrodes neat ILs afford weak cycling performance in the absence of organic additives (e.g. vinylene carbonate, VC). The potential formation of a [Li+]-OVC interaction/coordination could have a major influence on the observed electrochemical behavior of Li-ion batteries. On a specific electrolyte, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C1C6Im][NTf2] in association with Li[NTf2] (1mol...
August 17, 2018: Journal of Physical Chemistry. B
Chang Zhu, Qian Wang, Jiena Yun, Qiaoli Hu, Gang Yang
Non-covalent interactions play a critical role during the application of carbonaceous materials. DFT calculations are presently employed to study the non-covalent interactions of graphene flakes (GFs) with ion pairs, considering the impacts of doping (electron-deficient and electron-rich) and curving (direction, curvature and surface: inner and outer) as well as their combined effects. The results are relevant to carbon nanotubes, from which curved graphene sheets can be facilely produced. Doping changes the predominant binding configurations and fundamentally affects non-covalent interactions, and all dopants enhance the binding strength, especially the electron-deficient ones that alter frontier orbitals...
August 17, 2018: Physical Chemistry Chemical Physics: PCCP
Zheng Kun Yang, Cheng-Zong Yuan, An-Wu Xu
The development of low-cost and highly efficient single-atom oxygen reduction catalysts to replace platinum for fuel cells and metal-air cells is highly desirable but remains challenging. Herein, we report the fabrication of isolated single-atom Fe anchored on porous nitrogen-doped carbon from the pyrolysis of a well-designed solely Fe-tetrapyridophenazine coordination complex. The N-rich bridging ligand, tetrapyridophenazine (tpphz) is first employed as a spatial isolation agent of Fe that suppresses its aggregation during high temperature pyrolysis, resulting in highly reactive and stable single-atom Fe ORR catalysts...
August 17, 2018: Nanoscale
Hiroyuki Muramatsu, Masahiro Takahashi, Cheon-Soo Kang, Jin Hee Kim, Yoong Ahm Kim, Takuya Hayashi
We demonstrate selective nitrogen doping on the outer tubes of double walled carbon nanotubes by nitrogen plasma treatment. Such selectivity improves the chemical activity of the outer tubes, including their wettability and oxygen reduction reaction properties, while retaining the structural, optical, and electrical properties of the inner tubes.
August 17, 2018: Nanoscale
Mattia Scardamaglia, Carla Bittencourt
In this review, we discuss the use of doped carbon nanomaterials in catalysis, a subject that is currently intensively studied. The availability of carbon nanotubes since the 1990's and of graphene ten years later prompted the development of novel nanotechnologies. We review this topic linking fundamental surface science to the field of catalysis giving a timely picture of the state of the art. The main scientific questions that material scientists have addressed in the last decades are described, in particular the enduring debate on the role of the different nitrogen functionalities in the catalytic activity of nitrogen-doped carbon nanotubes and graphene...
2018: Beilstein Journal of Nanotechnology
Qianchun Zhang, Siqi Xie, Yanqun Yang, Yun Wu, Xingyi Wang, Jincheng Wu, Li Zhang, Junyu Chen, Yuan Wang
A facile, green, and high-output hydrothermal synthesis was proposed for the fabrication of highly fluorescent nitrogen-doped carbon quantum dots (N-doped CDs). The nitrogen content in N-doped CDs reached 19.2% and demonstrated strong blue fluorescence emission was obtained with fluorescence quantum yield (QY) of up to 32.9%, which exhibit high fluorescence quantum yield, high photostability, and excellent biocompatibility. The N-doped CDs possess high photostability, low toxicity, and excellent biocompatibility, based on which the N-doped CDs were successfully applied as a fluorescence probe for cell imaging...
2018: Journal of Analytical Methods in Chemistry
Hung Tan Pham, Minh Tho Nguyen
The geometries, bonding and abilities for CO2 capture of the doubly rhodium-doped boron cluster Rh2B18 are presented. DFT calculations using the TPSSh functional show that the doubly doped Rh2B18 is stable in a high symmetry shape (D9d) in which two Rh dopants are vertically and oppositely coordinated to nonagonal faces of a (2 × 9) double ring B18 tube, having the form of a teetotum toy. Bonding of the tube is analysed using different schemes for partition of total electron density (EDI_D, AIM). The high thermodynamic stability of Rh2B18 can be rationalized in terms of its electron distribution in which both Rh atoms share delocalized bonds with B atoms...
August 16, 2018: Physical Chemistry Chemical Physics: PCCP
Jingyang Tian, Haiyan Zhang, Zhenghui Li
In this work, a double-layer nitrogen-doped microporous hollow carbon@MoS2/MoO2 nanosphere (NCs@MoS2/MoO2) is prepared via a facile method utilizing Mo-mediated in situ growth on polyaniline-coated polystyrene spheres and carbonization process. Due to its unique structure, the as-obtained NCs@MoS2/MoO2 exhibits a high specific capacitance (569 F g-1 at 1 A g-1) and excellent rate performance (54.8 % capacitance retention) from 1 A g-1 (569 F g-1) to 20 A g-1 (312 F g-1) when directly used as supercapacitor electrode...
August 15, 2018: ACS Applied Materials & Interfaces
Sergey V Gnedenkov, Sergey L Sinebryukhov, Veniamin V Zheleznov, Denis P Opra, Elena I Voit, Evgeny B Modin, Alexander A Sokolov, Alexander Yu Ustinov, Valentin I Sergienko
Hafnium-doped titania (Hf/Ti = 0.01; 0.03; 0.05) had been facilely synthesized via a template sol-gel method on carbon fibre. Physico-chemical properties of the as-synthesized materials were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, scanning transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry analysis and Brunauer-Emmett-Teller measurements. It was confirmed that Hf4+ substitute in the Ti4+ sites, forming Ti1- x Hf x O2 ( x  = 0...
June 2018: Royal Society Open Science
Junkuo Gao, Yuhang Wu, Mengting Lu, Yuwen Li, Panpan He, Sireesh Babu Maddine, Juming Yao
Hydrogen production is one of the most effective methods to combat the global energy crisis. However, improving the electrochemical performance of oxygen evolution catalysts is a significant challenge. In this paper, exceptionally active electrocatalysts for the oxygen evolution reactions (OERs) were successfully developed and characterized using SEM, TEM, XRD, XPS and BET measurements. The nitrogen doped hollow carbon encapsulated bi-metallic nanoparticles (NHCNPs) were prepared using folic acid coordination polymerization...
August 14, 2018: Chemistry, An Asian Journal
Vera Schroeder, Timothy M Swager
Activating molecules or functional groups with high chemoselectivity in complex environments is the central goal of transition-metal-based catalysis. Promoting strong interactions between a selected substrate and a catalytic system can also be used to create highly selective and customizable sensors, and these concepts are widely recognized for enzymatic processes. We demonstrate the successful translation of organometallic reactions to sensing capability. Specifically, we have developed single-walled carbon nanotube (SWCNT) chemiresistive sensors for the highly selective detection of acrylates using conditions for the aerobic oxidative Heck reaction...
August 14, 2018: Journal of the American Chemical Society
Shuai Wang, Gyutae Nam, Ping Li, Haeseong Jang, Jia Wang, Min Gyu Kim, Zexing Wu, Xien Liu, Jaephil Cho
Developing highly efficient non-noble metal electrocatalysts for oxygen electrode reactions is highly desirable for industrial scale application in energy related devices. Herein, two new kinds of Ni (POxN3-x)2/NPC and Co (POxN3-x)2/NPC (NPC: N, P-co-doped carbon) are synthesized through a facile post-treatment of nickel- or cobalt-phytic acid xerogel, followed by an annealing procedure under an argon and ammonia atmosphere at 800 °C. The as-prepared catalysts exhibit outstanding catalytic activities for both the oxygen reduction and evolution reactions, which are comparable to those of Pt/C and IrO2...
August 14, 2018: Nanoscale
Simeng Dai, Yan Yuan, Jiangsheng Yu, Jian Tang, Jie Zhou, Weihua Tang
Metal-organic frameworks (MOFs) provide great opportunities for synthesizing advanced electrode materials with hierarchical hollow architectures for energy storage. Herein, we report the facile fabrication of core-sheath nanoarrays (NAs) on carbon cloth (CC@CoO@S-Co3O4) for binder-free electrode materials with MOFs as versatile scaffolds. The hollow S-doped Co3O4 sheath has been facilely prepared using a two-step synthetic protocol, which includes the surface etching of CoO nanowires for synchronous in situ growth of well-aligned ZIF-67 and its following hydrothermal process...
August 14, 2018: Nanoscale
Yanyan Sun, Shuang Li, Zarko Jovanov, Denis Bernsmeier, Huan Wang, Benjamin Paul, Xingli Wang, Stefanie Kuehl, Peter Strasser
Carbon materials doped with nitrogen are active catalysts for the electrochemical two-electron oxygen reduction reaction (ORR) to hydrogen peroxide. Insights into the individual role of the various chemical nitrogen functionalities in the H2O2 production, however, have remained scarce. Here, we explore a novel, catalytically very active family of nitrogen-doped porous carbon materials, prepared by direct pyrolysis of ordered mesoporous carbon (CMK-3) with polyethylenimine (PEI). Voltammetric rotating ring-disk analysis in combination with chronoamperometric bulk electrolysis measurements in electrolysis cells demonstrate a pronounced effect of the applied potentials, current densities, and electrolyte pH on the H2O2 selectivity and absolute production rates...
August 13, 2018: ChemSusChem
Zhen Zhang, Ping Li, Qi Feng, Bing Wei, Chenglong Deng, Jiantao Fan, Hui Li, Haijiang Wang
Designing highly active, stable and cost-efficient electrocatalysts as alternatives to replace Pt is extremely desirable for the hydrogen evolution reaction (HER). Despite much progress that has been made based on complete non-precious metals (NPM), very few NPM catalysts have showed comparable performance to Pt-based catalysts. Herein, a cost-efficient, environmentally-friendly and scalable method to synthesize novel ruthenium(Ru)-doped transition metal carbide (Mo2C) hybrid catalyst was proposed. The hybrid nanoparticles were uniformly distributed and strongly embedded in biomass-derived highly porous N-doped carbon framework...
August 13, 2018: ACS Applied Materials & Interfaces
Kexin Zhang, Chong Qu, Zibin Liang, Song Gao, Hao Zhang, Bingjun Zhu, Wei Meng, Engang Fu, Ruqiang Zou
Oxygen reduction and evolution reactions as two important electrochemical energy conversion processes in metal-air batteries devices have aroused widespread concern. However, synthesis of low-cost non-noble metal-based bifunctional high performance electrocatalysts is still a great challenge. In this work, we report on the design and synthesis of a novel Co-B/N co-doped carbon with core-shell-structured nanoparticles aligned on graphene nanosheets (denoted as CoTIB-C/G) derived from cobalt tetrakis(1-imidazolyl)borate (CoTIB) and graphene oxide hybrid template...
August 13, 2018: ACS Applied Materials & Interfaces
Mengistie L Debasu, Jesse C Riedl, J Rocha, Luís D Carlos
The mechanism of upconversion enhancement for Li+-doped materials is still contentious. Attempting to settle the debate, here the upconversion emission enhancement of (Y0.97-xYb0.02Er0.01Lix)2O3, x = 0.000-0.123, nanoparticles is studied. Li+ incorporation in the Y2O3 host lattice is achieved via co-precipitation and solid-state reaction routes. In contrast to numerous reports, elemental analysis reveals that the former method does not afford Li+-bearing nanoparticles. The solid-state reaction route accomplishes an effective Li+ doping, as witnessed by inductively coupled plasma atomic emission spectroscopy and X-ray photoelectron spectroscopy (XPS)...
August 13, 2018: Nanoscale
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"