Networks of DNA-templated palladium nanowires: structural and electrical characterisation and their use as hydrogen gas sensors.
نویسندگان
چکیده
Electroless templating on DNA is established as a means to prepare high aspect ratio nanowires via aqueous reactions at room temperature. In this report we show how Pd nanowires with extremely small grain sizes (< 2 nm) can be prepared by reduction of PdCl4(2-) in the presence of lambda-DNA. In AFM images the wires are smooth and uniform in appearance, but the grain size estimated by the Scherrer treatment of line broadening in X-ray diffraction is less than the diameter of the wires from AFM (of order 10 nm). Electrical characterisation of single nanowires by conductive AFM shows ohmic behaviour, but with high contact resistances and a resistivity (-10(-2) omega cm) much higher than the bulk value for Pd metal (-10(-5) cm @ 20 degrees C). These observations can be accounted for by a model of the nanowire growth mechanism which naturally leads to the formation of a granular metal. Using a simple combing technique with control of the surface hydrophilicity, DNA-templated Pd nanowires have also been prepared as networks on an Si/SiO2 substrate. These networks are highly convenient for the preparation of two-terminal electronic sensors for the detection of hydrogen gas. The response of these hydrogen sensors is presented and a model of the sensor response in terms of the diffusion of hydrogen into the nanowires is described. The granular structure of the nanowires makes them relatively poor conductors, but they retain a useful sensitivity to hydrogen gas.
منابع مشابه
Improving Gas Sensing Properties of Tin Oxide Nanowires Palladium-Coated Using a Low Cost Technique
Thin films of SnO2 nanowires were successfully prepared by using chemical vapor deposition (CVD) process on quartz substrates. Afterwards, a thin layer of palladium (Pd) as a catalyst was coated on top of nanowires. For the deposition of Pd, a simple and low cost technique of spray pyrolysis was employed, which caused an intensive enhancement on the sensing response of fabricated sensors...
متن کاملElectrodeposition of nanowires for the detection of hydrogen gas
Nanowires composed of noble metals are attractive candidates for chemical sensors because they are both ductile and chemically stable in air. The single application where electrodeposited metal nanowires have had the largest impact is that of hydrogen gas (H2) sensing. The development of sensitive, selective, power-effi cient, rapid-responding, and inexpensive H2 sensors, for the purpose of det...
متن کاملReliability of Sensors Based on Nanowire Networks When the Electrical Current is Allowed to Move in All Directions
Nanowire networks have great potential in many industrial applications, including batteries, electrical circuits, solar cells, and sensors. In this paper we focus on a specific hydrogen gas nanosensor whose sensing element is a network of palladium nanowires. The nanosensor is modeled using a square, equilateral triangle, and hexagonal lattice. We provide the reliability behavior of this nanose...
متن کاملSynthesis of Serrated GaN Nanowires for Hydrogen Gas Sensors Applications by Plasma-Assisted Vapor Phase Deposition Method
Nowadays, the semiconductor nanowires (NWs) typically used in hydrogen gas sensors. Gallium nitride (GaN) with a wide band gap of 3.4 eV, is one of the best semiconductors for this function. NWs surface roughness have important role in gas sensors performance. In this research, GaN NWs have been synthesized on Si substrate by plasma-assisted vapor phase deposition at different deposition time, ...
متن کاملLow-Dimensional Palladium Nanostructures for Fast and Reliable Hydrogen Gas Detection
Palladium (Pd) has received attention as an ideal hydrogen sensor material due to its properties such as high sensitivity and selectivity to hydrogen gas, fast response, and operability at room temperature. Interestingly, various Pd nanostructures that have been realized by recent developments in nanotechnologies are known to show better performance than bulk Pd. This review highlights the char...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Faraday discussions
دوره 164 شماره
صفحات -
تاریخ انتشار 2013