Synthesis and analysing the structural, optical, morphological, photocatalytic and magnetic properties of TiO2 and doped (Ni and Cu) TiO2 nanoparticles by sol–gel technique

In the present work, Ni2+ and Cu2+ ions are doped with TiO2 using sol–gel technique. The effects of Ni and Cu doping in TiO2 matrix are characterized by XRD, Micro-Raman, FTIR, UV–DRS, PL, and FESEM with EDS. Furthermore, it is analyzed for photocatalytic activity and magnetic applications. From XRD analysis, it is observed that the peaks corresponding to the planes match with the JCPDS data [anatase: 89-4203] of TiO2. The crystallite size of the doped samples is found to be greater than that of TiO2. Micro-Raman analysis shows the confirmation of anatase phase of TiO2. FTIR analysis confirms the presence of functional groups which are presented in the prepared samples. From UV–DRS, the band-gap values of TiO2 and doped TiO2 (Ni2+, Cu2+) are found to be 3.25, 2.48, and 1.25 eV. Photoluminescence (PL) results show an emission edge of Ni- and Cu-doped TiO2 is red shifted which is due to the vacancies of titanium and oxygen imported subsequently during doping. The surface morphology and the elemental composition of Ni- and Cu-doped TiO2 nanoparticles are also analyzed. The photocatalytic activity of all the prepared samples are assessed by methylene blue dye as testing pollutant and visible radiation. The test reveals that Cu–TiO2, Ni–TiO2, and TiO2 show the degradation efficiency of 68.14, 61.04, and 33.32%, thereby showing that the doped TiO2 are more efficient in degrading the pollutant and can be applied for future photocatalytic applications. From VSM analysis, the saturation magnetization of Ni–TiO2 and Cu–TiO2 is found to be weak and can be improved by the synthesis process and the proportion of dopant.