Photocatalytic activity of Nd-doped ZnO for the degradation of CI. reactive blue 4 in aqueous suspension

Nd-doped ZnO nanoparticles with different Nd contents were synthesized and characterized by X-ray power diffraction, UV-vis, X-ray photoelectron spectroscopy, infrared spectra, and high-resolution transmission electron microscope. The results revealed that the particle size of Nd-doped ZnO is much smaller than that of pure ZnO, which is critical for enhancing the photocatalytic activity. The photocatalytic activity of Nd-doped ZnO with different Nd loading was compared with pure ZnO, and the effects of the solution pH in the degradation of C.I. Reactive Blue 4 were studied. It was observed that the rate of degradation of C.I. Reactive Blue 4 over Nd-doped ZnO increases with increasing Nd loading up to 2.5 mol % and then decreases. The rate of degradation reaches a maximum value approximately at pH = 11 and then decreases. Among the catalyst studied, the 2.5 mol % Nd-doped ZnO was the most active, and the degradation rate of C.I. Reactive Blue 4 could reach 91.25% in 90 min when the concentration of the catalyst was 0.1 g/L.