Microwave-assisted rapid synthesis of honeycomb core-ZnO tetrapods nanocomposites for excellent photocatalytic activity against different organic dyes

[Display omitted] •Graphene nanosheets- ZnO nanocomposites (GZnTPs) have been prepared quickly.•Microwave-assisted rapid approach (300 W, 180 s) has been employed.•A unique ZnO tetrapods nanostructure has been grown over the carbon core.•GZnTPs act as excellent photocatalysts for Rodamine B (RhB).•Maximum degradation efficiency (91.6%) achieved against RhB by GZnTPs under UV. Microwave-assisted rapid approach (300 W, 180 s) has been demonstrated for the synthesis of graphene nanosheets (GNs)-zinc oxide (ZnO) nanocomposites. It is noted that the microwave process not only fastens the nucleation and growth but also gives better control to engineer anisotropic nanostructure over a carbon core. In the studied system, surface morphological analysis reveals the well-defined growth of a ZnO tetrapods (TPs) nanostructure over the carbon core (graphene). Raman signature confirms the formation of GNs-ZnO tetrapods (GZnTPs) nanocomposites with a tri-layered GNs system. GZnTPs exhibits a lower bandgap (3.09 eV) than that of pure EG and ZNTPs. Best photocatalytic activities are noticed for the GZnTPs owing to the recombination of photogenerated electrons. GZnTPs are tested for their ability to photodegrade Rhodamine B (RhB), Methyl orange (MO), and Methylene blue (MB) dyes under UV and visible (both 125 W) light irradiation. GZnTPs act as excellent photocatalysts for RhB with a maximum degradation efficiency of 91.6% under UV light irradiation and stable for three cycles.