Facile fabrication of SnO2 / MoS2 / rGO ternary composite for solar light-mediated photocatalysis for water remediation

Abstract

Tin oxide (SnO2) nanostructure has potential application for the removal of organic contaminants from industrial effluents. However, higher bandgap value (3.8 eV and fast recombination of charge carriers (e- - h+ pair)) have limited its applications. To overcome these limitations, we have proposed a double Z-scheme strategy, which not only reduced the rate of recombination but lso provides a new pathway for charge carriers to degrade the organic toxins. SnO2 surface sensitization with MoS2 nanofibers by hydrothermal method followed by composite formation with reduced graphene oxide (rGO) via ultrasonication was employed as photocatalyst for methylene blue (MB) degradation. The surface sensitized SnO2 with MoS2 and its composite with rGO were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-rays (EDX), and ultraviolet-visible (UV-Vis.) spectroscopy. XRD analysis revealed that SnO /MoS2 heterostructure has very small crystallite. From UV-visible studies, a redshift was observed for the SnO2 /MoS2 heterostructure as compared to SnO2, which further extends to the visible spectrum with the introduction of reduced graphene oxide (rGO). The photocatalytic studies revealed that SnO2 /MoS2 /rGO composite significantly improved the photocatalytic efficiency up to 90% under 75 min in the presence of solar light. EIS measurements exhibited that SnO2/MoS2/rGO has better charge transfer and mass transfer potential as compared to SnO2.