Photocatalytic degradation of brilliant green and 4-nitrophenol using Ni-doped Gd(OH) 3 nanorods.

Gadolinium hydroxide (Gd(OH) 3 ) was synthesized via a microwave-assisted synthesis method. Nickel ion (Ni 2+ ) was doped into Gd(OH) 3 , in which 4-12% Ni-Gd(OH) 3 was synthesized, to study the effect of doping. The structural, optical, and morphological properties of the synthesized materials were analyzed. The crystallite sizes of the hexagonal structure of Gd(OH) 3 and Ni-Gd(OH) 3 , which were 17-30 nm, were obtained from x-ray diffraction analysis. The vibrational modes of Gd(OH) 3 and Ni-Gd(OH) 3 were confirmed using Raman and Fourier-transform infrared spectroscopies. The band gap energy was greatly influenced by Ni-doping, in which a reduction of the band gap energy from 5.00 to 3.03 eV was observed. Transmission electron microscopy images showed nanorods of Gd(OH) 3 and Ni-Gd(OH) 3 and the particle size increased upon doping with Ni 2+ . Photocatalytic degradations of brilliant green (BG) and 4-nitrophenol (4-NP) under UV light irradiation were carried out. In both experiments, 12% Ni-Gd(OH) 3 showed the highest photocatalytic response in degrading BG and 4-NP, which is about 92% and 69%, respectively. Therefore, this study shows that Ni-Gd(OH) 3 has the potential to degrade organic pollutants.