Fabrication of a Novel Z-Scheme Bi2moo6/Gqds/Mos2 Hierarchical Nanocomposite for the Photocatalytic Decomposition of Ofloxacin and Cr(Vi) as Aqueous Micropollutants

The development of a novel MoS2/Bi2MoO6 composite photocatalyst has been carried out, which was further sensitized using graphene quantum dots (GQDs) for multiple photocatalytic applications in the field of antibiotic remediation and Cr(VI) reduction. A simple chemical mixing procedure was used to prepare the GQD-MoS2/BMO composite photocatalyst. The degradation efficiency observed for an aqueous phase of ofloxacin and hexavalent chromium was 99.5 and 97.2% after 100 and 30 min of photochemical reaction under visible-light irradiation, respectively. The excellent photocatalytic performance is attributed to the improved light absorption owing to the GQDs and promotion of charge transfer between Bi2MoO6 and MoS2 via the GQDs through a Z-scheme mechanism and the electron attracting properties of the GQDs. Consequently, the photocatalytic mechanism has been deduced based on the energy-band positions with support from scavenger investigations and probing techniques confirming the reactive species responsible for the degradation of ofloxacin and reduction of Cr(VI)