Fabrication of TiO2 @MoS2 heterostructures with improved visible light photocatalytic activity

The spread application of Titanium dioxide (TiO2) is severely limited by the rapid recombination of photogenerated electron-hole pairs (e--h+). For many applications, two-dimensional (2D) molybdenum disulfide (MoS2), with large specific surface area and sufficient active sites, has been widely researched as a beneficial support for TiO2 photocatalytic activity enhancement. The synthesized heterostructures, the 2D MoS2 nanosheets loaded with brown TiO2 particles (b-TiO2@MoS2) were manufactured through an ultrasound aided electrochemical exfoliation of natural bulk molybdenite coupled with sol-gel technique at low temperature (180 ºC). SEM, TEM, HRTEM, XRD, XPS, UV–vis absorption, Raman, PL spectra, and photocurrent analysis were used to investigate the morphology, microstructure, composition, and charge separation property of the samples. It was determined that b-TiO2 @MoS2 heterostructures had photocatalytic activity by observing their degradation of butyl xanthate during 120 min of visible light irradiation. Furthermore, the photocatalytic effectiveness of the 1 wt% b-TiO2 @MoS2 heterostructures is 94.80%, with a maximum rate constant (k value) of 0.01764 min−1. In contrast to brown TiO2, the findings indicated that the b-TiO2 @MoS2 heterostructures enhanced visible light absorption, the expansion of active sites, the separation and transfer of photogenerated charges. A probable degradation mechanism of photodegradation butyl xanthate and charge transfer process of b-TiO2 @MoS2 heterostructures under visible light irradiation were also postulated.