A comparative study on impact of the synthesis techniques on the catalytic properties of Ni-doped titania

In the present study, nickel-doped titania (NiTiO2) has been prepared using sol–gel (S-NiTiO2) and the hydrothermal (H-NiTiO2) methods. XRD of both samples depicted NiTiO2 with an anatase phase, but the S-NiTiO2 had a highly crystalline structure. In the optical spectra, S-NiTiO2 showed a slight decrement in bandgap (3.20 eV) compared to undoped titania (3.26 eV), while the bandgap of H-NiTiO2 has decreased drastically to 3.08 eV. FESEM depicted the morphologies of the prepared doped nanoparticles (NPs). The catalytic dye degradation/reduction efficiency of prepared samples was studied by using Rhodamine B (RhB) and 4-Nitrophenol (4-NP). It was observed that the prepared nanoparticles can be efficiently used as catalysts to degrade the dyes and for the reduction of 4-Nitrophenol. S-NiTiO2 and H-NiTiO2 degraded Rhodamine B completely in 13 min and 7 min, respectively. 4-Nitrophenol is degraded by 90.16%, and 77.52% in the presence of S-NiTiO2 and H-NiTiO2 respectively. In the case of catalytic studies, the H-NiTiO2 exhibited enhanced efficiency compared to pure and S-NiTiO2 nanoparticles.