Adsorption and sonocatalytic performance of magnetite ZnO/CuO with NGP variation

A series of Fe₃O₄/ZnO/CuO/nanographene platelets (Fe₃O₄/ZnO/CuO/NGP) nanocomposites with various NGP weight percents were studied as catalysts for methylene blue removal under adsorption followed by sonocatalytic process. Weight percents (wt.%) of NGP in the nanocomposites were varied (5, 10, and 15 wt.%). The physicochemical properties of the samples were characterized using X-Ray diffraction (XRD), ultraviolet-visible (UV-VIS) spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis, and a vibrating sample magnetometer (VSM). The heterogeneous structure of all samples consisted of the cubic spinel structure of Fe₃O₄, hexagonal wurtzite structure of ZnO, monoclinic structure of CuO, and graphite-like structure of NGP. With increasing NGP weight percent, sample surface area increased from 14 m²/g to 23 m²/g. Adsorption and sonocatalytic activity were examined on degradation of methylene blue in alkaline conditions. The results show that the adsorption ability of samples increased with increasing NGP weight percent. However, in the sonocatalytic process, Fe₃O₄/ZnO/CuO/NGP with 10 wt.% NGP exhibited the maximum degradation. The effect of addition different radical scavenger was also examined to understand the sonocatalytic mechanism.