Abstract: The present invention discloses a gas sensor made of field effect transistor based on ZnO nanowires (ZnO-FET) which operates according to the principle of metal-oxide-semiconductor field effect transistor (MOSFET) and has a charge carrier channel made of ZnO nanowires between source and drain. The gas sensor device disclosed in the present invention has three electrodes-gate, source and drain, so that it is different from the known gas sensor device which has only two electrodes-cathode and anode. The ZnO nanowires as charge channel in the gas sensor device of the present invention is an n-type semiconductor with high specific surface area, and its electric resistance can be controlled by the gate bias, so that the capability of the present device for sensing gas can be largely promoted.

Abstract: The present invention discloses a gas sensor made of field effect transistor based on ZnO nanowires (ZnO-FET) which operates according to the principle of metal-oxide-semiconductor field effect transistor (MOSFET) and has a charge carrier channel made of ZnO nanowires between source and drain. The gas sensor device disclosed in the present invention has three electrodes-gate, source and drain, so that it is different from the known gas sensor device which has only two electrodes-cathode and anode. The ZnO nanowires as charge channel in the gas sensor device of the present invention is an n-type semiconductor with high specific surface area, and its electric resistance can be controlled by the gate bias, so that the capability of the present device for sensing gas can be largely promoted.

Abstract: A powder containing Fe—Ni nano-particles and a method for manufacturing the powder, wherein the powder containing Fe—Ni nano-particles includes a carrier and Fe—Ni nano-particles. The carrier is a ceramic particle with size of about micro-meter (?m). Fe and Ni atoms of the Fe—Ni nano-particles exist simultaneously on the surface of the carrier by electroless plating technology. The atomic ratio of the Fe and Ni atoms can be controlled by changing the relative concentration of the plating solution and the plating condition. The method for manufacturing the powder containing Fe—Ni nano-particles includes the following steps: preparation process, sensitization process, activation process, electroless plating process, and after-deposition process. The manufactured powder has small volume and large surface area. The contact chance between Fe/Ni bimetal and chlorinated organic substance is largely increased. It can be used to treat various environmental pollutants or for some catalytic reactions.

Abstract: The invention provides a powder containing carbon nanotube or nanofiber and a process for producing the same. Said powder containing a carbon nanotube or nanofiber is composed of a carrier and a carbon nanotube or nanofiber. Said carrier is a micrometer-sized particle such as Al2O3, SiO2, TiO2, CaO, SiC, WC and an acrylic high molecular sphere. Said carbon nanotube or nanofiber is grown on the surface of the carrier by a chemical vapor deposition (CVD) method and their diameter is in a range of several nanometer to several hundreds nanometer. Said carbon nanotube or nanofiber is a multi-wall carbon nanotube (MWCNT) and is in a curved shape. Said process for producing said powder containing a carbon nanotube or nanofiber comprises a pretreatment, a sensitization treatment, an activation treatment, an electroless plating treatment and a growth treatment.