Photocatalytic performance of Nd-TiO2 coatings: effect of voltage and frequency

Neodymium (Nd)-titanium dioxide (TiO2) micro-arc oxidation (MAO) coatings were formed in a phosphate-based electrolyte with the addition of neodymium (III) oxide (Nd2O3) using suitable voltages and frequencies. Scanning electron microscopy results revealed that the coatings varied with different voltages and frequencies. Furthermore, composition analysis showed the neodymium-titanium dioxide coatings were mainly composed of anatase and rutile phases. Meanwhile, the anatase content increased and then decreased. In addition, X-ray photoelectron spectroscopy results indicated that the titanium (Ti) 2p spin-orbit components of the neodymium-titanium dioxide coatings shifted toward a higher binding energy, suggesting that some of the neodymium (Nd3+) ions combined with the titanium dioxide lattice, leading to dislocation. Furthermore, photocatalytic experiment results showed that the photocatalytic activity of neodymium-titanium dioxide coatings can be greatly enhanced with a moderate amount of neodymium ions. However, an excessive amount of neodymium ions does not improve the photocatalytic activity further.

Automated summary

Neodymium-titanium dioxide micro-arc oxidation coatings were formed by adding neodymium (III) oxide in a phosphate-based electrolyte with appropriate voltages and frequencies. The coatings varied with different voltages and frequencies, consisting mainly of anatase and rutile phases. The presence of neodymium ions affected the lattice of titanium dioxide, leading to dislocation. The photocatalytic activity of the coatings was enhanced with a moderate amount of neodymium ions, but excessive amounts did not further improve activity.