Abstract: The invention provides a method and materials for removing a metal contaminant from a water sample, as well as composites and methods for making composites.

Abstract: A method is disclosed of synthesizing ?-alumina/hematite (?-Al2O3/Fe2O3) composite nanofibers for removing heavy metals from a water source. The method includes preparing a polymer solution, the polymer solution comprising an iron precursor, acetic acid and a polymer; adding a select amount of an aluminum precursor to the polymer solution; and electrospinning the polymer solution and the select amount of the aluminum precursor to form the ?-Al2O3/Fe2O3 composite nanofibers.

Abstract: A gas sensor operable at ambient conditions, the sensor includes functionalized feather-like tellurium (Te) nanostructures on single-walled carbon nanotube (SWNTs) networks.

Abstract: A selective nanoscale asymmetric gas sensor is disclosed, the sensor including a first electrode having a Schottky-type contact to a nanoengineered transducer with a barrier height between energy levels of the first electrode and the nanoengineered transducer; and a second electrode having an Ohmic contact to the nanoengineered transducer with a smaller or no barrier height than the first electrode. The first electrode can be palladium and the second electrode can be gold.

Abstract: A selective nanoscale asymmetric gas sensor is disclosed, the sensor including a first electrode having a Schottky-type contact to a nanoengineered transducer with a barrier height between energy levels of the first electrode and the nanoengineered transducer; and a second electrode having an Ohmic contact to the nanoengineered transducer with a smaller or no barrier height than the first electrode. The first electrode can be palladium and the second electrode can be gold.

Abstract: A gas sensor operable at ambient conditions, the sensor includes functionalized feather-like tellurium (Te) nanostructures on single-walled carbon nanotube (SWNTs) networks.

Abstract: A gas sensing device (nanosensor) includes a substrate with at least a pair of conductive electrodes spaced apart by a gap, and an electrochemically functionalized semiconductive nanomaterial bridging the gap between the electrodes to form a nanostructure network. The nanomaterial may be single-walled carbon nanotubes (SWNTs) functionalized by the deposition of nanoparticles selected from the group consisting of an elemental metal (e.g., gold or palladium), a doped polymer (e.g., camphor-sulfonic acid doped polyaniline), and a metal oxide (e.g. tin oxide). Depending on the nanoparticles employed in the functionalization, the nanosensor may be used to detect a selected gas, such as hydrogen, mercury vapor, hydrogen sulfide, nitrogen dioxide, methane, water vapor, and/or ammonia, in a gaseous environment.

Abstract: Conducting polymer nanowires can be doped with analyte-binding species to create a nanowire that has a different conductivity depending on the presence or absence of the analyte.

Abstract: Provided is a method for preparing a chalcogenic hybrid nanostructure including: (a) adding a chalcogenic nanostructure, an electron donor and an electron acceptor to a medium containing metal-reducing bacteria to prepare a reaction mixture, the electron acceptor including a chalcogen element; and (b) performing a metal reduction reaction using the prepared reaction mixture to prepare a chalcogenic hybrid nanostructure with the chalcogen element of the electron acceptor incorporated. The present disclosure provides a new method allowing preparation of a chalcogenic hybrid nanostructure comprising three or more components using metal-reducing bacteria. The disclosure allows preparation of a nanostructure in a more economical and eco-friendly manner. The disclosure also allows control of morphological, physical/chemical and electrical properties of the prepared nanostructure. In addition, the present disclosure provides a nanomaterial that can be useful in nanoelectronic and optoelectronic devices.

Abstract: A gas sensing device (nanosensor) includes a substrate with at least a pair of conductive electrodes spaced apart by a gap, and an electrochemically functionalized semiconductive nanomaterial bridging the gap between the electrodes to form a nanostructure network. The nanomaterial may be single-walled carbon nanotubes (SWNTs) functionalized by the deposition of nanoparticles selected from the group consisting of an elemental metal (e.g., gold or palladium), a doped polymer (e.g., camphor-sulfonic acid doped polyaniline), and a metal oxide (e.g. tin oxide). Depending on the nanoparticles employed in the functionalization, the nanosensor may be used to detect a selected gas, such as hydrogen, mercury vapor, hydrogen sulfide, nitrogen dioxide, methane, water vapor, and/or ammonia, in a gaseous environment.