Two-dimensional MoS2 nanosheet-modified oxygen defect-rich TiO2 nanoparticles for light emission and photocatalytic applications

Improvements in the charge transfer interface and efficient light utilization have proven to be essential parameters for the superior performance of heterostructure-based photocatalysis. In the present study, 2D MoS2 nanosheet-modified oxygen defect-rich anatase TiO2 nanostructures were developed by the hydrothermal method. Elemental mapping and transmission electron microscopy studies affirmed the functionalization of 2D MoS2 nanosheets with TiO2 nanoparticles. Raman spectroscopy and XRD studies confirmed the formation of the MoS2–TiO2 heterojunction. UV-DRS studies exhibited improved visible light absorption and significant bandgap narrowing in TiO2 nanostructures with the modification of 2D MoS2 nanosheets. PL results also displayed an improvement in the charge separation and reduction in the recombination rate in MoS2-modified TiO2. White light emission PL was achieved through modulation in the defect concentration of TiO2 with the attachment of MoS2 nanosheets. MoS2-modified TiO2 nanostructures showed remarkable photodegradation nature for methylene blue (MB) dye degradation under sunlight. The most efficient MoS2-modified TiO2 decomposed 98.3% of MB, 84.7% of oxytetracycline hydrochloride (OTC-HCl) and 80% of methyl orange (MO) molecule solution in just 12 minutes, 50 minutes and 30 minutes, respectively, under sunlight. The enhanced photolysis performance of MoS2–TiO2 nanohybrids can be ascribed to the efficient light utilization and synergistic effects among the MoS2 and defect-rich TiO2 nanoparticles.