Graphene quantum dots modified hexagonal prisms h-MoO3 for enhanced photocatalytic degradation of methylene blue under UV light irradiation

Currently, photocatalytic degradation is a fascinating technology due to its capability to treat escalating environmental problems by degrading chemicals like dyes and pharmaceuticals from wastewater. Herein, the hexagonal prism GQDs/h-MoO3 composite photocatalyst was fabricated through a facile hydrothermal approach. The synthesized samples were identified by XRD, SEM, FT-IR, XPS, UV-Vis DRS, and PL technologies to study the crystal structure, morphology, surface chemical composition, and optical properties. The preparation circumstances of binary compounds, such as different GQDs (Graphene quantum dots) loading amounts, precursor solution pH, hydrothermal temperature, and hydrothermal time were optimized, also, and the photocatalytic activity of materials is determined by photodegradation of Methylene Blue in this approach, which systematically investigated the impact of operational conditions on the efficiency of the photocatalytic reaction. The results revealed that 10GQDs/h-MoO3 has the best photocatalytic performance among competitors, which exhibited a high photodegradation efficiency (85.58%) of MB, and the rate was approximately 2.13 times greater than pristine h-MoO3. Moreover, the PL and EIS measurements proved the outstanding separation and migration ability of the photo-excited carriers of composite, which was attributable to the fact that GQDs can serve as electron transporters and acceptors to induce electron-hole separation efficiently. Finally, the free radical scavenging experiments confirmed that the primary active species was h+ in the photocatalytic process, as well as a potential explanation for the improved photocatalytic activity of GQDs/h-MoO3 photocatalysts was proposed.