Abstract
Synthesis of magnetically separable Cu0.5Zn0.5AlxFe2-xO4 nanoparticles was carried out via a chemical co-precipitation route. The synthesis of Cu0.5Zn0.5AlxFe2-xO4-rGO nano-heterostructures was done by the ultrasonication method. Cu0.5Zn0.5AlxFe2-xO4 nanoparticles were characterized by X-ray diffraction (XRD). XRD analysis confirmed the cubic spinel structure of Cu0.5Zn0.5Fe2O4 nanoparticles and its derivatives (Cu0.5Zn0.5AlxFe2-xO4, where x = 0.00, 0.03, 0.06, 0.09, 0.12, and 0.15). The substitution of Fe3+ ions with Al3+ ions was confirmed by peak shifting in recorded XRD patterns. Further, an energy-dispersive X-ray analysis of all samples showed the variation in Fe3+ and Al3+ contents quantitatively. The characterization of graphite oxide (GO) and reduced graphene oxide (rGO) was carried out via XRD, UV-visible (UV-Vis.), and Raman spectroscopy. The data of all these three techniques confirmed the formation of rGO and GO. The fully characterized rGO was then utilized for making nano-heterostructures with Cu0.5Zn0.5AlxFe2-xO4 nanoparticles. Scanning electron microscopy analysis confirmed the formation of ferrite nanoparticles-rGO nano-heterostructures. The Cu0.5Zn0.5AlxFe2-xO4 nanoparticles and Cu0.5Zn0.5AlxFe2-xO4-rGO nano-heterostructures were subjected to various types of characterizations for their potential applications. Electrochemical impedance spectroscopy revealed that the charge transfer resistance significantly reduced for nano-heterostructures as compared to bare Cu0.5Zn0.5Al0.03Fe1.97O4 nanoparticles. The photocatalytic degradation efficiency of the prepared nanoparticles and their nano-heterostructures with rGO was carried out by monitoring the degradation of typical organic compound methylene blue (MB) using UV-Vis. spectroscopy. It is interesting to note that the photocatalytic activity of Cu0.5Zn0.5AlxFe2-xO4 photocatalyst was significantly increased when Cu0.5Zn0.5Al0.03Fe1.97O4/rGO nanocomposites were used as a catalyst. This is because of rGO as it takes the light generated electron from the conduction band of catalyst immediately and thus inhibits the immediate recombination of e(-)-h(+) pairs. Secondly, due to the large surface area of rGO sheets, several MB molecules could be adsorbed on its surface. The adsorbed molecules later on degraded by the photocatalytic reaction.