Cost-effective scalable synthesis of few layers MoS2 based thin film for sunlight enforced photocatalytic activity

Abstract Two-dimensional (2D) semiconductor nanostructures have gained tremendous interest in the field of environmental remediation and water purification. Nanostructures coated surfaces provide new insight for the development of cost-effective advanced photocatalyst. In this study, 2D-MoS2 nanosheets based coating has been developed through the combined effort of the exfoliation and a spin coating method. Microscopy analysis inferred the formation of nanosheets from the bulk structured MoS2 with the reduction in their average dimensions. Exfoliated MoS2 nanosheets formed in 18 h reaction time has average length ~1019 nm and width~544 nm. Cross-sectional SEM studies confirm the formation of MoS2-PVA thin films with different orientation of MoS2 nanosheets. UV–Vis absorption spectroscopy studies exhibit two peaks at 619 nm and 680 nm with improved optical absorption. The XRD and Raman spectroscopy analysis reveals the 2H-phase of MoS2 nanosheets. 2D-MoS2-PVA composite thin film was tested as an advanced photocatalyst coating for the breakdown of methylene blue (MB) and malachite green (MG) pollutant molecules under sunlight. 2D-MoS2-PVA composite thin film decomposed the 5 μM solution of MB and MG molecule solutions in 80 min and 40 min, respectively, under sunlight (800 W/cm2). The efficient photodegradation performance of the 2D-MoS2-PVA composite indicates their potential usage in other environmental applications.