Filtration

/Tag: Filtration

Efficient mixed-solvent exfoliation of few-quintuple layer Bi 2 S 3 and its photoelectric response

2017-07-20T10:28:39+00:00July 20th, 2017|Categories: Publications|Tags: |

A scalable liquid exfoliation of layered Bi 2 S 3 employing a mixed-solvent strategy was used for the fabrication of Bi 2 S 3 nanosheets. We found that 10% deionized water in 90% isopropyl alcohol is the best mixed solvent for the efficient and effective exfoliation of layered Bi 2 S 3 . These results are consistent with the absorbance spectra and enthalpy of mixing theory. The obtained Bi 2 S 3 nanosheets had few-quintuple layers and were investigated by transmission electron microscopy, atomic force microscopy, and Raman spectroscopy. These Bi 2 S 3 nanosheets can be used to fabricate large-scale thin films by filtration method; the films demonstrated sensitive photoelectric response with the rise and decay response of photocurrent on the sub-second scale under visible light excitation. The electronic structures of bulk and one-quintuple layer Bi 2 S 3 are calculate…

Published in: "Nanotechnology".

Graphitic carbon nitride membrane for water filtration

2017-07-31T08:27:10+00:00July 10th, 2017|Categories: Editorial, Research|Tags: |

Scientists from South China University of Technology and Leibniz Uni Hannover demonstrate graphitic carbon nitride membranes with ultralow friction water transport.

The membranes show promising characteristics for water purification with high water permanence and good salt rejections.

Read more:  “Water Transport with Ultralow Friction through Partially Exfoliatedg-C3N4Nanosheet Membranes with Self-Supporting Spacers” Wang et al. Angewandte Chemie 2017

Graphene membranes allows selective sieving of ions

2017-06-27T20:50:40+00:00January 24th, 2017|Categories: Editorial, Research|Tags: , , |

Scientists from the The University of Manchester demonstrate the ability to control the interlayer spacing in graphene membranes by physical confinement, paving the way for their use in filtration technologies.

The level of tunability comes from combining pristine graphene and graphene oxide in pre-determined rations, which allows the tuning of the membranes hydrated radius. The different hydrated radii allow permeation of different ions, determined by the ion’s size.

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Thermal conductivity of hBN laminates reaches 20W/mK

2015-12-17T11:05:34+00:00December 18th, 2015|Categories: Editorial, Research|Tags: , |

Writing in a paper published on pre-print repository arXiv, scientists from Xiamen University, BGT Materials and the University of Manchester report the preparation and thermal transport characterization of hexagonal boron nitride paper.

The samples were prepared by vacuum filtration of hBN dispersion prepared using liquid exfoliation techniques in isopropanol. The resulting paper can be freestanding with thickness ranging from 10 to 100um. The thermal conductivity is calculated from the thermal diffusivity, measured using the laser flash method.

It was found that hBN paper thermal conductivity varies with respect to the packing density of the samples: compressed laminates show improved thermal conductivity up to 20w/mK. It is expected that such laminates can find applications as heat spreading materials where electrically insulating but thermally conductive laminates are required.

Further reading: “High thermal conductivity of hexagonal boron nitride laminates

Water desalination with a single-layer MoS2 nanopore

2015-10-15T06:13:53+00:00October 15th, 2015|Categories: Publications|Tags: , |

Article Nanopores in two-dimensional materials are arousing considerable interest as filtration membranes to solve the problem of providing fresh water to a growing population. Here, the authors evaluate the potential of single-layer MoS 2 to effectively reject salt ions whilst maintaining high flow rates.Nature Communications doi: 10.1038/ncomms9616Authors: Mohammad Heiranian, Amir Barati Farimani, Narayana R. Aluru

Published in: "Nature Communications".

Intercorrelated Superhybrid of AgBr Supported on Graphitic-C3N4-Decorated Nitrogen-Doped Graphene: High Engineering Photocatalytic Activities for Water Purification and CO2 Reduction

2015-09-30T22:16:39+00:00September 30th, 2015|Categories: Publications|Tags: , |

AgBr nanoparticles supported on graphitic-C3N4-decorated nitrogen-doped graphene intercorrelated ternary superhybrid composites (ACNNG-x) acting as a novel visible-light driven photocatalyst are reported. Because of the fast interfacial charge separation and photoelectrochemical performance, the representative of ACNNG-50 superhybrid structure achieves high efficiency and stable photocatalytic capability for organic contaminant degradation and CO2 reduction.

Published in: "Advanced Materials".

Atomistic understandings of reduced graphene oxide as an ultrathin-film nanoporous membrane for separations

2015-09-24T06:16:07+00:00September 24th, 2015|Categories: Publications|Tags: , , |

Article Ultrathin-film nanoporous membranes promise low-cost and high-performance separation for applications such as water desalination and the purification of natural gas. Here, the authors adopt a molecular dynamics approach to assess the potential of reduced grapheme oxide as such a material.Nature Communications doi: 10.1038/ncomms9335Authors: Li-Chiang Lin, Jeffrey C. Grossman

Published in: "Nature Communications".

Graphene-decorated porous ceramics[space]for[space]efficient removal of Cr(VI)

2016-10-15T11:33:52+00:00July 24th, 2015|Categories: Publications|Tags: , |

By Shi Wang RSC Adv., 2015, Accepted ManuscriptDOI: 10.1039/C5RA09684G, PaperShi Wang, Wen Yang, Guohua ChenPorous ceramics (such as activated alumina(AA)) is a common adsorbent material in water purification. Its purifying capacity can be greatly improved through modification of porous ceramics. In this paper, a…The content of this RSS Feed (c) The Royal Society …read more

Published in: RSC Advances

Catalysis: Sulfur and Nitrogen Co-Doped Graphene for Metal-Free Catalytic Oxidation Reactions (Small 25/2015)

2016-10-15T11:39:47+00:00July 1st, 2015|Categories: Publications|Tags: , |

By Xiaoguang Duan, Kane O’Donnell, Hongqi Sun, Yuxian Wang, Shaobin Wang Metal-based catalysts have been widely used for the aqueous-phase oxidation of organic pollutants for water purification. Metal-free catalysis in the oxidative degradation of pollutants is now reported by H. Sun, S. Wang, and co-workers on page 3036. Using density functional theory and rational design, sulfur and nitrogen co-doping into 2D …read more

Published in: Small

Rapid Method for the Purification of Graphene Oxide

2016-10-15T11:48:57+00:00May 27th, 2015|Categories: Publications|Tags: , , |

By Gabriel Ceriotti RSC Adv., 2015, Accepted ManuscriptDOI: 10.1039/C5RA07604H, PaperGabriel Ceriotti, Anna Yu. Romanchuk, Alexander Slesarev, Stepan N. KalmykovA rapid and facile purification method for graphene oxide (GO) is important for its production above the gram scale. Such a method would allow for the development of GO’s large-scale…The content of this RSS Feed …read more

Published in: RSC Advances

Size Fractionation of Graphene Oxide Sheets via Filtration through Track-Etched Membranes

2016-10-15T11:53:35+00:00May 8th, 2015|Categories: Publications|Tags: , , |

By Ji Chen, Yingru Li, Liang Huang, Naer Jia, Chun Li, Gaoquan Shi
Graphene oxide (GO) fractionation is achieved by size exclusive passing of GO sheets through size-defined pores of track-etched membranes which separate the GO sample into three portions with narrow size distributions. The method reported here can be used for the performance improvement of graphene-based materials.
…read more

Published in: Advanced Materials

Plugging up leaky graphene

2016-10-15T11:53:57+00:00May 8th, 2015|Categories: News|Tags: , |

By Jennifer Chu | MIT News Office For faster, longer-lasting water filters, some scientists are looking to graphene —thin, strong sheets of carbon — to serve as ultrathin membranes, filtering out contaminants to quickly purify high volumes of water.

Graphene’s unique properties make it a potentially ideal membrane for water filtration or desalination. But there’s been one main …read more

Published in: MIT press office

Polymer nanocomposites from free-standing, macroscopic boron nitride nanotube assemblies

2016-10-15T11:56:18+00:00April 30th, 2015|Categories: Publications|Tags: , |

By Keun Su Kim RSC Adv., 2015, Accepted ManuscriptDOI: 10.1039/C5RA02988K, CommunicationKeun Su Kim, Michael Jakubinek, Yadienka Martinez-Rubi, Behnam Ashrafi, Jingwen Guan, Kayla O’Neill, Mark Plunkett, Amy Hrdina, Shuqiong Lin, Stephane Denommee, Christopher Kingston, Benoit SimardHere we report fabrication of free-standing boron nitride nanotube (BNNT) sheets by direct deposition and by vacuum filtration methods, including …read more

Published in: RSC Advances

Environmentally benign and facile reduction of graphene oxide by flash light irradiation

2016-10-15T11:57:24+00:00April 27th, 2015|Categories: Publications|Tags: , , |

By Sung-Hyeon Park and Hak-Sung Kim In this work, we demonstrate an environmentally benign and facile flash light irradiation process to
reduce graphene oxide (GO). GO thin films were prepared by a vacuum filtration process, and these
films were reduced by exposure to flash light irradiation for a few milliseconds at room temperature
under ambient conditions. Flash light conditions …read more

Published in: Nanotechnology

Graphene-based integrated electrodes for flexible lithium ion batteries

2016-10-15T11:58:23+00:00April 23rd, 2015|Categories: Publications|Tags: , |

By Ying Shi, Lei Wen, Guangmin Zhou, Jing Chen, Songfeng Pei, Kun Huang, Hui-Ming Cheng and Feng Li We have prepared flexible free-standing electrodes with anode and cathode active materials deposited
on a highly conductive graphene membrane by a two-step filtration method. Compared with conventional
electrodes using metal as current collectors, these electrodes have displayed stronger adhesion,
superior electrochemical performance, higher energy density, and better flexibility. A full lithium
ion battery assembled …read more

Published in: 2DMaterials

Plasma-induced graphene nanopores show promise for desalination

2016-10-15T12:06:32+00:00March 25th, 2015|Categories: Editorial, Research|Tags: , |

Editorial

In a paper published as an advanced online publication in Nature Nanotechnology scientists have found a new way to controllably decorate graphene with nanometre sized pores. While previous efforts in perforating graphene concentrated on using bombardment by ions (most notably Gallium), the currently technique uses a low-cost and high throughput oxygen plasma.

The technique relies on transferring single crystal CVD graphene over through holes, etched on silicon nitride substrate. Through standard transfer techniques (PMMA/acetone) and post-treatment (Ar/H annealing) graphene can be suspended over these micron-sized trenches. Finally, a brief (1-5s) exposure to a 20W O plasma perforated graphene and enabled water permeation. Importantly, the scientists report nanopores with controlled periodicity, varying as a function of exposure to the plasma and monitored through Raman and SEM.

The technique yields extraordinary salt rejection rates of nearly 100% as well as promising flux rates, both of which are highly desirable. However, the preparation of the membranes remains a tedious task, with a device yield of 20% (supplementary information section #6) . Although the use of CVD graphene on an industrial scale remains a considerable challenge, the findings may accelerate development in the area of  graphene filtration and desalination.

Scientific publication: “Water desalination using nanoporous single-layer graphene” Nature Nanotechnology

 

 

Self-Powered Electronics by Integration of Flexible Solid-State Graphene-Based Supercapacitors with High Performance Perovskite Hybrid Solar Cells

2016-10-15T12:07:35+00:00March 21st, 2015|Categories: Publications|Tags: , |

By Pengcheng Du, Xiaowen Hu, Chao Yi, Huckleberry C. Liu, Peng Liu, Hao-Li Zhang, Xiong Gong To develop high-capacitance flexible solid-state supercapacitors and explore its application in self-powered electronics is one of ongoing research topics. In this study, self-stacked solvated graphene (SSG) films are reported that have been prepared by a facile vacuum filtration method as the free-standing electrode for flexible solid-state supercapacitors. The highly hydrated …read more

Published in: Advanced Functional Materials

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