Аннотация:Nowadays, 2D monolayers, nanotubes (NTs), and closed-cage structures
composed MoS2 and WS2, attract growing attention due to their unique
behaviour including mechanical, tribological, semiconducting, and optical
properties. Surface modification of WS2 NTs by metal and metal oxide
nanoparticles was shown to result in functional catalytic and magnetic
materials. However, little was known about MoS2 and WS2 nanostructures
modified with plasmonic nanoparticles.
Here we report a pioneering method for decoration of WS2 NTs and MoS2
nano-onions with gold (AuNP) and silver nanoparticles [1]. AuNPs were grown
on the disulphide surface using direct reaction of MoS2/WS2 suspensions with
aqueous HAuCl4 solutions at 100oC. Variation of HAuCl4 concentration allowed
tuning of AuNPs mean size in 5-35 nm range. The same method employing
AgNO3 and [Ag(NH3)2]OH solutions was used for production of silver-decorated
disulphide nanostructures. Surface defects of MoS2/WS2 were shown to play a
key role in the reactions of disulphides with noble metal ions. Femtosecond
transient absorption spectroscopy of the obtained nanocomposites suggested
the charge transfer between plasmonic nanoparticles and semiconducting
disulphides upon optical excitation. The applicability of the designed
nanocomposites for sensing of oxidizing gases (like nitrogen oxides) will also be
discussed.
