Abstract:
In this research project, well-organized MoS2/TiO2 (nanosheets/nanoparticles)
composites have been prepared via facile sol-gel reflux synthesis without the use of any
surfactant and template. The goal was to utilize MoS2 with Titania as a photosensitizer
due to its small band gap and to employ this synthesized product for photocatalytic
activities. Bulk MoS2 has been exfoliated via liquid phase exfoliation (LPE) process and
separated at 1000 and 500rpm centrifugation speeds respectively to obtain sheets of
different sizes and densities. These sheets were then added in TiO2 sol in 0.1, 0.5, 1, 2
and 5wt. % ratios respectively. MoS2 nano-sheets acted as a photosensitizer for TiO2
nanoparticles due to their enhanced band gaps. The prepared composites were
characterized by SEM, AFM, XRD, Raman analysis, UV-Vis and BET techniques. The
SEM results confirmed the adsorption of TiO2 nanoparticles on MoS2 sheets. The AFM
results also confirmed the formation of nano-sheet like structure of MoS2. These
composite systems were then employed for photodegradation of organic dye (methylene
blue) which is effluent produced by industries. Enhanced photodegradation of methylene
blue was observed by MoS2 sheets and TiO2 nanoparticles hybrid structures as compared
to commercial P25 TiO2 powder and as-prepared anatase TiO2 powder under UV
irradiation. Photo-mechanism to elucidate this degradation was also suggested. Also, the
prepared composites were also exploited for energy storage application (supercapacitor).
The capacitance of exfoliated sheets centrifuged at 1000 and 500 rpm was measured. .
These sheets showed better results due to enhanced surface area. The sheets centrifuged
at 500rpm showed superior properties as compared to 1000rpm sheets as enhanced
surface area allows higher discharging. It was seen that MoS2/TiO2 composites showed
better results for capacitance as compared to pure anatase TiO2.
