MWCNTs attached neodymium doped-ZnO photocatalysts for efficient removal of dyes from wastewater

The present study involves the synthesis of neodymium-doped zinc oxide nanoparticles decked multiwalled carbon nanotubes (Nd-ZnO-MWCNTs) with different weight percentage compositions of Nd through the co-precipitation method. The synthesized photocatalysts were utilized in photocatalytic removal of acid blue 40 and eosin Y dye solutions via visible light irradiation. The influence of catalyst dose and dye concentrations on the degradation efficiency was also studied. The catalysts were characterized using XRD, FTIR, BET surface area analysis, UV-Vis and TEM spectroscopies. TEM revealed that the Nd-ZnO nanoparticles were well distributed on the MWCNTs surface. XRD analysis showed that the ZnO occurred in the wurtzite phase. The introduction of Nd and MWCNTs reduced the band gap of ZnO from 3.2 to 2.7 eV resulting in its enhanced visible light absorption. All the modified ZnO photocatalysts degraded the dye at higher efficiencies compared to the bare ZnO with 0.6% Nd-ZnO-MWCNTs being the most effective. The bare ZnO degraded 13% of acid blue 40 dye while 0.6% Nd-ZnO-MWCNTs exhibited 99% degradation efficiency. The synergistic effect of Nd and MWCNTs was identified to be responsible for the enhanced efficiency of the Nd-ZnO-MWCNTs photocatalysts.