Synthesis of g-C3N4/ZnO nanostructures via mechano-thermal method for photocatalytic degradation of methylene blue dye

The g-C3N4/ZnO hybrid nanostructures were prepared by a facile mechano-thermal method and the structural characteristics of the prepared nanomaterials were investigated by employing XRD, FTIR, UV-Vis, FESEM, BET, and EDS analytical techniques. The N-2 sorption isotherm revealed that g-C3N4/ZnO nanoheterostructures have a specific surface area of 10.856 m(2)/g and a pure volume of 0.0409 cc/g, and mesoporosity. The photocatalytic ability of the obtained photocatalysts was analyzed for the degradation of MB dye under visible light illumination. The degradation of MB dye was found to be significantly influenced by the dopant amount of ZnO in g-C3N4, initial MB concentration, solution pH, and catalyst quantity. The photocatalytic performance of the all-prepared hybrid g-C3N4/ZnO nanostructures is determined decidedly superior in comparison to bare g-C3N4 and ZnO, and the optimized values of operational parameters are estimated to be 25% of ZnO in g-C3N4 [g-C3N4/ZnO(25%)], 30 mg/L of dye solution (50 mL), pH = 10, and 20 mg of catalyst dose amount. 99.54%, 52.52%, and 35.58% of MB dye is degraded in 60 min of visible light irradiation at pH = 10 over g-C3N4/ZnO (25%), g-C3N4, and ZnO, respectively, while the pseudo-first rate constant values for the MB degradation were estimated to be 87.73 x 10(-3), 11.30 x 10(-3), and 6.56 x 10(-3), respectively. The enhanced photocatalytic efficiency of the g-C3N4/ZnO nanoheterostructures could be due to the creation of heterojunction by the coupling of two semiconductors of well-matched band structures in which effective charge transfer has occurred. The prepared g-C3N4/ZnO demonstrated significant photostability after utilization in four runs of cycles with a retention of 92% efficiency. The O-<middle dot>(2)- is the main reactive species participating in the degradation of MB dye.