A Single Palladium Nanowire Via Electrophoresis Deposition Used as a Ultrasensitive Hydrogen Sensor

We have successfully fabricated and demonstrated the use of a single metallic nanowire as a hydrogen sensor with extremely high sensitivity via a very simple fabrication process. In this paper, single palladium (Pd) nanowires were electrodeposited within 100-nm-wide polymethylmethacrylate nanochannels using a Pd electrolyte solution. Via this method, nanowires were grown with widths ranging from 50 to 100 nm, and lengths from 3 to 7 mum. The nanowires were successfully used to sense hydrogen concentrations as low as 5 ppm at room temperature. The growth control of single Pd nanowires, as well as the primary sensing mechanism, is addressed in detail in this paper.