Impact of structural, morphological and electrical properties of Gd_xTi_1−xO₂ nanocomposites on the photocatalytic degradation of Rhodamine B dye

Gd_xTi_1−xO₂ nanocomposites with different weight% were synthesized by sol–gel process. The structural, morphological, electrical and optical properties of the nanocomposites were characterized through X-ray diffraction, high resolution scanning electron microscope, transmission electron microscope, impedance analysis and UV-VIS-NIR spectra. The structural study showed that the nanocomposites crystallized in tetragonal structure with anatase titania phase. Microstructure analysis reveals that the nanocomposites are in spherical shape with size between 10 and 16 nm. The increase in the bulk resistance observed in impedance analysis with Gd inclusion in TiO₂ is corroborated with the decrease in the crystallite size from XRD. Photocatalytic activities of all the samples were investigated for the degradation of RhB dye. Best degradation efficiency of 96% resulted in x = 0.10 composition of Gd_xTi_1−xO₂ nanocomposites. The half filled electronic configuration of gadolinium in the composites facilitates the improvement of degradation efficiency through effective separation of electron–hole pair and mobility of oxygen vacancies.