High photocatalytic efficiency of α-Fe2O3 - ZnO composite using solar energy for methylene blue degradation

Abstract

The present report illustrates the photocatalytic degradation of methylene blue dye under solar energy through α-Fe2O3 - ZnO composite synthesized by adopting a facile and simple chemical method. Various characterization techniques particularly X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR), etc., have been employed to characterize the as-synthesized composite. The XRD reveals the successful formation of the as-synthesized sample. The TEM studies illustrate the agglomeration of particles with sizes in the range of ∼10–60 nm. HRTEM micrograph indemnifies the formation of lattice fringes pertaining to inter-planner spacing∼ 0.149 nm and ∼0.138 nm corresponding to (214) reflection plane of hematite and (112) reflection plane of ZnO, respectively. The as-synthesized α-Fe2O3 – ZnO composite shows double absorption edges which correspond to the bandgap of α-Fe2O3 (2.2 eV) and ZnO (3.2 eV). Furthermore, α-Fe2O3 - ZnO composite shows a remarkable enhanced degradation capacity than bare hematite nanoparticles and zinc oxide nanoparticles, and α-Fe2O3 – ZnO (1:2) composite demonstrates the best degradation performance among all the variants. Moreover, it clearly suggests that the UV part of solar light plays a vital role in the catalytic degradation of methylene blue whereas the visible part of light remains unresponsive.