Based on their electronic conductivity behavior, metallic nanowires may have electronic applications ranging from interconnects to sensors. We have recently developed an electrochemical method for synthesizing metal nanowires (Pd, Cd, Mo, Au, Ag, Cu,…) ranging in diameter from a few tens of nanometer to 1 μm with millimeter lengths. These nanowires are prepared by the electrodeposition of metal at step edges present on a graphite surface. These nanowires can be used to connect metal nanoparticles (Ni, Au…) or, once transferred in a polymer cast, can operate as sensors. In this paper, we shall describe the general method of preparation of such naked and beaded nanowires as well as how may these nanowires be manipulated to make electronic devices. As an example of such nanodevice, a brief overview of the characteristics of the first nanowire-based sensor for hydrogen gas (H2) will be given.

Metal nano- and microparticles that are narrowly dispersed in diameter can be electrodeposited on graphite basal plane surfaces using the two-step method: First, a voltage pulse with a duration of 5 ms and an overpotential, η=−500 mV was used to nucleate metal particles on the graphite surface. Then, a growth pulse with an overpotential, η, of −20 to −250 mV was applied to grow the metal particles obtained in step 1 to the desired final diameter. For a variety of metals, including silver, gold, platinum, molybdenum, and nickel, this ‘slow-growth’ method yielded dispersions of particles ranging in diameter from 50 nm to 2 μm having a relative standard deviation (RSDdia=σdia/〈dia〉) as low as 7%.