Recent advances in multistep solution nanosynthesis of nanostructured three-dimensional complexes of semiconductive materials

AbstractConstructing simply nanostructured zero-, one-, and two-dimensional crystallites into three-dimensional multifunctional assemblies and systems at low-cost is essential and highly challenging in materials science and engineering. Compared to the simply nanostructured components, a three-dimensional (3D) complex made with a precisely controlled spatial organization of all structural nanocomponents can enable us to concert functionalities from all the nanocomponents. Methodologically, so doing in nm-scales via a solution chemistry route may be much easier and less expensive than via other mechanisms. Hence, we discuss herein some recent advances in multistep solution syntheses of nanostructured 3D complexes of semiconductors with a focus mainly on their synthetic strategies and detailed mechanisms

Composite membranes and applications thereof

In one aspect, a composite membrane comprises a polymeric host comprising polybenzimidazole or polybenzimidazole derivative and graphene oxide dispersed in the polymeric host, the graphene oxide at least partially functionalized with phosphonic acid moieties, phosphonate moieties or combinations thereof. In some embodiments, the functionalized graphene oxide is homogeneously dispersed in the polymeric host and/or is not agglomerated in the polymeric host

TiO2 nanostructures, membranes and films, and methods of making same

One aspect of the present invention relates to a method for synthesizing macro-sized nanostructures. The method in one embodiment comprises the steps of mixing an amount of TiO2 powders with a volume of an alkali or alkaline solution to form a mixture, and heating the mixture at a temperature higher than 160 degree C. for a period of time effective to allow TiO2-containing, macro-sized nanostructures to form, wherein the TiO2-containing, macro-sized nanostructures form in an environment that has no presence of a substrate that comprises Ti. These TiO2-containing, macro-sized nanostructures can be utilized to form a free standing membrane, and/or a three-dimensional (3D) structure

Biocompatible scaffold for sensing proteins

This invention related to a biocompatible scaffold that can detect redox-active chemicals and biomolecules electrochemically. In one embodiment, the biocompatible scaffold includes a substrate, and a conductive layer of TiO2-containing nanowires or nano fibers formed on the substrate, wherein the conductive layer of TiO2-containing nanowires or nanofibers is formed with a pore structure, and wherein when the biocompatible scaffold is in contact with a biological analyte, one or more proteins of the biological analyte are immobilized on a surface of the conductive layer Of TiO2- containing nanowires or nanofibers so as to generate a measurable faradic current signal

TiO2 nanostructures, membranes and films, and applications of same

This invention describes the applications of TiO2-containing, macro-sized nanostructures in the fields including photocatalysis, information writing-erasing-rewriting, microfiltration, controlled drug release, and tire making. In one aspect, the present invention relates to a method of photocatalytically decomposing organic pollutants. The method includes the steps of mixing a solution containing organic pollutants and a plurality of TiO2-containing, macro-sized nanostructures to form a mixture and exposing the mixture to UV irradiation to decompose the organic pollutants

Multivalent cation crosslinking suppresses highly energetic graphene oxide’s flammability

The authors acknowledges National Science Foundation- Experimental Program to Stimulate Competitive Research (NSF-EPSCoR) for partial support, Prof. S. Yu’s lab for the micro-Raman experiments, and Dr. Jingyi Chen’s lab for the TGA study.Graphene oxide (GO), a common intermediate for making graphene-like materials from graphite, was recently found to possess an explosive fire-hazard that can jeopardize the GO’s large-scale production and wide applications. This work reports a simple and facile method to cross-link the GO with Al3+ cations, in one step, into a freestanding flexible membrane. This inorganic membrane resists in-air burning on an open-flame, at which non-cross-linked GO was burnt out within ~5 seconds. All characterization data suggested that the in-situ “epoxy ring opening” reactions on GO surface facilitated the cross-linking, which elucidated a new mechanism for the generalized inorganic polymerization. With the much improved thermal- and water-stabilities, the cross-linked GO-film can help to advance high-temperature fuel-cells, electronic packaging, etc. as one of the long-sought inorganic polymers known to date.PostprintPeer reviewe

Titanate nanowire, titanate nanowire scaffold, and processes of making same

This invention relates to a synthetic nanostructure. In one embodiment, the synthetic nanostructure has a top region substantially comprising titanate nanowires, a middle region substantially comprising titanate nanoparticles and titanate nanowires, and a bottom region substantially comprising titanium. Some of the titanate nanowires of the top region are extending into the middle region, the middle region is between the top region and the bottom region, and some of the titanate nanowires of the top region are substantially perpendicular to the bottom surface of the titanium substrate. At least some of the titanate nanowires in the top region form 3D macroporous scaffolds with interconnected macropores

Initial Growth of Single-Crystalline Nanowires: From 3D Nucleation to 2D Growth

The initial growth stage of the single-crystalline Sb and Co nanowires with preferential orientation was studied, which were synthesized in porous anodic alumina membranes by the pulsed electrodeposition technique. It was revealed that the initial growth of the nanowires is a three-dimensional nucleation process, and then gradually transforms to two-dimensional growth via progressive nucleation mechanism, which resulting in a structure transition from polycrystalline to single crystalline. The competition among the nuclei inside the nanoscaled-confined channel and the growth kinetics is responsible for the structure transition of the initial grown nanowires