Simultaneously-Engineered Composition and Spatial Position of Metal/Metal-Oxide Nanowires for Hydrogen Sensing Applications

Abstract

The application of metal and metal-oxide nanowires in functional electronic nanodevices requires the precise control of the composition and surface alignment of the nanowires. Herein, a facile route for fabricating highly ordered Pt, In2O3, and Pt/In2O3 hybrid nanowire arrays from their acid/salt precursors by nanoscale solution printing is reported. The resulting nanowire arrays are continuous and periodic with sub-100 nm dimensions and aligned in parallel on a silicon substrate. With the prepared metal/metal-oxide nanowire arrays, two types of hydrogen sensors were fabricated. The sensors fabricated with the hybrid Pt/In2O3 nanowire array show better H2 detection performance than the sensors fabricated with the pure Pt nanowire array with regard to the response amplitude (50 times higher) and the detection limit of the sensor. The improvement of the Pt/In2O3-based sensor compared to the Pt-based sensor indicates the occurrence of an additional enhancing mechanism through the chemical sensitization of the Pt/In2O3-based sensors. Moreover, the sensors were integrated into a compact hydrogen detection system with remote hydrogen (H2) monitoring and gas leakage warning functions. As the developed approach can be adapted for different materials by simply adjusting the ratio of precursor solutions, it offers a promising straightforward method to fabricate composition-tunable hybrid nanowire arrays for low-cost, scalable, and high-quality nanoscale sensors.