Fabrication of (Y2O3)n-ZnO nanocomposites by high-energy milling as potential photocatalysts

The photodegradation of Congo red dye by (Y2O3)(n) ZnO photocomposites was investigated through a sequence of experiments. X-ray diffraction analysis indicates nanocomposites' evolution having the ZnO wurtzite structure with increase in crystallite size and Y2O3 phase segregation, as confirmed by the appearance and gradual growth of the Y2O3 peak. Field emission scanning electron microscopy observations reveal irregular spherical morphology with increased agglomeration due to Y2O3 loading. Diffuse reflectance spectra exhibit bandgap widening and red shift of the absorption edge with the doping process. Brunauer-Emmett-Teller analysis denotes improved porosity as manifested by the surface area, pore diameter, and pore volume increments after yttrium loading. Fortuitously, photocatalysts demonstrate excellent photodegradation rates for CR dye, reaching 93% at a higher rate of 43 x 10(-3) min(-1). The photocomposite 1% Y2O3-ZnO exhibits a threefold enhancement in the visible photocatalytic process in an aqueous solution. The photocatalytic performance is discussed in detail concerning pH and oxygen species, which contribute to the photodegradation of CR dye. The results obtained in this study clearly highlight the superior performance (Y2O3)(n) ZnO as a highly efficient photocatalyst in the degradation of dyes in water.