Investigation of Gd-doped mesoporous TiO2 spheres for environmental remediation and energy applications

The TiO₂ is considered by many as the most versatile material with a very large number of applications in many fields that includes photocatalysis and dye-sensitized solar cell (DSSC). But it is active mainly in the UV region of the spectrum due to its large band gap, around 3.2 eV, which causes low photon absorption. This limitation can be overcome by doping TiO₂ with a lanthanide which enhances the absorption of visible photons. In this report, we investigated pure mesoporous TiO₂ and Gd-doped mesoporous TiO₂ spheres to analysis its photocatalytic and energy conversion efficiency. Gadolinium was chosen due to its stable 4f orbitals state of Gd³⁺ ions. The XRD spectra and Raman spectra analysis confirms the presence of TiO₂. It was noted that only anatase was in all the synthesised samples. The morphological analysis confirms FESEM, HRTEM and Element mapping analysis confirms the formation of mesoporous structures with gadolinium incorporated on the mesosphere's surface. The synthesis samples' photocatalytic activity was studied and sample with 1 mmol of Gd was found to perform best among all the samples. A DSSC study was also conduct and Gd-doped TiO₂ was found to out-perform the TiO₂.