One-pot sol-gel synthesis of reduced graphene oxide uniformly decorated zinc oxide nanoparticles in starch environment for highly efficient photodegradation of Methylene Blue

ZnO NPs + reduced graphene oxide (rGO) nanocomposites were synthesized using a sol-gel method with starch as the polymerisation agent. Long-chain starch compounds were used to terminate the growth of the ZnO NPs on rGO and stabilise them. The resulting products were annealed at 350 degrees C to remove the starch and produce a reduced graphene oxide (rGO) sheet in one-pot without any post-annealing processes. Microscopic studies showed that the NPs were dispersed on the rGO sheet. They had a spherical shape and a size of approximately 25 +/- 10 nm. In addition, these studies revealed that the NPs were single crystals. The X-ray diffraction pattern of the NPs indicated a hexagonal (wurtzite) structure. The results of Fourier transform infrared spectrum analysis (FTIR) revealed that the GO sheet was transformed into rGO via the sol-gel method in the starch environment. The results of photoluminescence spectroscopy demonstrated that the incorporation of reduced graphene oxide (rGO) sheets with ZnO NPs suppressed the electron-hole recombination of the composite. Therefore, a significant enhancement in the photocatalytic degradation of methylene blue (MB) was observed with the ZnO NPs + rGO nanocomposite compared to the bare ZnO nanoparticles.