WS2 nanotubes dressed in gold and silver: Synthesis, optoelectronic properties, and NO2 sensing

Abstract

This conference contribution is focused on decoration of WS2 nanotubes (NT-WS2) with gold and silver nanoparticles via facile routes implying direct reaction of tungsten disulfide with water-soluble AuIII and AgI species at 100°C. The underlying mechanism of these interactions will be discussed in details based on extensive studies of reaction mixtures and resulting metal–NT-WS2 nanocomposites, including thorough X-ray photoelectron spectroscopy (XPS) analysis. Surprising features in optical spectra of the designed nanocomposites would be reported, including suppression of plasmon resonance in tiny noble metal nanoparticles (< 10\u2005nm in diameter) grown onto NT-WS2. The plasmonic features of individual gold nanoparticles on the surface of disulfide nanotube were also characterized by electron energy loss spectroscopy in scanning transmission electron microscopy mode (STEM-EELS). Photoresistive NO2−sensing response of NT-WS2 under green light illumination (λmax = 530\u2005nm) and its enhancement by plasmonic gold “nanoantennas” will be reported as well.