Porous Au-embedded WO(3) Nanowire Structure for Efficient Detection of CH(4) and H(2)S

We developed a facile method to fabricate highly porous Au-embedded WO(3) nanowire structures for efficient sensing of CH(4) and H(2)S gases. Highly porous single-wall carbon nanotubes were used as template to fabricate WO(3) nanowire structures with high porosity. Gold nanoparticles were decorated on the tungsten nanowires by dipping in HAuCl(4) solution, followed by oxidation. The surface morphology, structure, and electrical properties of the fabricated WO(3) and Au-embedded WO(3) nanowire structures were examined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and current–voltage measurements. Formation of a nanowire structure resulted in significant enhancement in sensing response to H(2)S and CH(4) gases. Furthermore, Au embedment into the WO(3) nanowire structures remarkably improved the performance of the sensors. The increase in response performance of sensors and adsorption–desorption kinetic processes on the sensing layers were discussed in relation with the role of Au embedment.