Atomic layer deposition of TiO_(2) on carbon-nanotubes membrane for capacitive deionization removal of chromium from water

Chromium(Cr)is a common heavy metal that has severe impacts on the ecosystem and human health.Capacitive deionization(CDI)is an environment-friendly and energy-efficient electrochemical purification technology to remove Cr from polluted water.The performance of CDI systems relies primarily on the properties of electrodes.Carbon-nanotubes(CNTs)membranes are promising candidates in creating advanced CDI electrodes and processes.However,the low electrosorption capacity and high hydrophobicity of CNTs greatly impede their applications in water systems.In this study,we employ atomic layer deposition(ALD)to deposit TiO_(2) nanoparticulates on CNTs membranes for preparing electrodes with hydrophilicity.The TiO_(2)-deposited CNTs membranes display preferable electrosorption performance and reusability in CDI processes after only 20 ALD cycles deposition.The total Cr and Cr(VI)removal efficiencies are significantly improved to 92.1%and 93.3%,respectively.This work demonstrates that ALD is a highly controllable and simple method to produce advanced CDI electrodes,and broadens the application of metal oxide/carbon composites in the electrochemical processes.

Preparation of Durable Emitter of Electrospray Mass Spectrometry by Covalently Coating the Fused-Silica Capillary Tip with Carbon-Nanotube Sol-Gel Composite Material

A simple approach for the preparation of emitter of electrospray ionization mass spectrometry by covalently coating the fused-silica capillary tip with the conductive carbon-nanotube sol-gel composite material(CNTSCM)is described.The CNTSCM was prepared by dispersing single-walled carbon nanotubes in the sol composed of a mixture of 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane,and ethanol.The long-term sta-bility of the prepared ESI emitters was demonstrated by at least 180 h of continuous use.Signal intensity obtained by the prepared emitter was mass-flux sensitive when the flow rate was lower than 500 nL/min,while the signal in-tensity performed a concentration dependence when the flow rate was in the range of 500-800 nL/min.The use-fulness of such a prepared emitter was demonstrated by the analysis of various types of samples such as organic small molecular drugs,oligosaccharide,peptide,and protein.

All carbon non-covalent exohedral hybrids:C60 aggregates on nanotube networks

Exohedral van der Waals （vdW） hybrids comprising pristine carbon nanotubes （CNTs） and C60 fullerenes are expected to enable the engineering of carbonaceous materials with tunable physical and chemical properties due to the unperturbed sp2 hybridization of the comprising allotropes. In spite of theoretical predictions, experimental realization of exohedral non-covalent hybridization of unmodified C60 fullerenes and CNTs was not reported before, probably due to the relatively strong inter-fullerene and inter-tube interactions that drive the system toward phase separation and the formation of fullerene crystals and CNTs bundles. Here we describe a two-step process for preparation of C60-CNTs hybrids. The first step is based on solution-assembly of random, 3D-networks of individual, pristine CNTs followed by fast solvent-quenching. In the second step sublimated fullerenes are deposited onto the pre-assembled networks where structural defects serve as nucleation points for fullerite nanocrystals. Annealing at low temperature （80 ℃） results in re-organization of the C6o nanocrystals into nanometric layers, forming a CNT-C6o core-shell like cylindrical hybrids. Raman characterization and the observed high mobility of the fullerenes at the CNT surface support the assumption that the exohedral hybrids are of vdW type. The approach presented here offers a pathway for preparation of exohedral hybrids with controlled nano- morphology： CNTs-networks decorated by nanometric C60 crystals and CNTs-3D-networks coated by a shell of non-covalently bonded mono- or multi-layers of C60 molecules that may serve to shape the nanomorphology of the active layer in polymer-fullerene bulk-heterojunction solar cells.