Synthesis and characterisation of Cu - Doped TiO2 nanoparticles for DSSC and photocatalytic applications

In the present work, copper-doped TiO2 nanoparticles were synthesized via sol-gel technique with different molar concentration of copper precursor (0.025 M-CT-1, 0.05 M-CT-2, 0.1 M-CT-3 and 0.2 M-CT-4). The effect of copper doping on the structural, morphological, compositional, optical and electrical properties of TiO2 was systematically analyzed for its better suitability as photoanode in Dye-Sensitized Solar Cells (DSSC) and photocatalyst in dye degradation. From structural analysis, all the synthesized samples show anatase phase with a tetragonal crystal system. The broadening and shift in the peaks of the synthesized samples show the successful incorporation of Cu ions into TiO2 lattices. All the synthesized samples exhibit spherical shape morphology with slight agglomeration. EDS analysis exhibit the purity of the synthesized nanoparticles with the presence of only Ti, O, and Cu. UV-DRS analysis reveals the decrease in reflectance of the TiO2 with increasing the Cu concentration. The bandgap values of the Cu-TiO2 decreased from 2.66 to 2.40 eV with the increase of copper concentration. From PL analysis, the peak observed at 380.20, 469.56 and 535.24 nm corresponds to the band-band PL emission, free excitons, and oxygen vacancies, respectively. Further, we have fabricated DSSC using Cu-doped TiO2 as a photoanode without treatment of any scattering layer and we have obtained the maximum efficiency of 3.90% for 0.1 M Cu-TiO2 (CT-3). Similarly, the maximum degradation efficiency of 97.12% was obtained against rhodamine-B dye with the highest regression coefficient (R-2 = 0.9957) and lesser half-life degradation time (t(1/2) = 47.1428 min) for CT-3. This higher efficiency was not reported elsewhere using Cu-dopant concentrations. From these observations, it was concluded that 0.1 M concentration of Cu was the optimum dopant concentration with TiO2 which was suitable for DSSC and photocatalytic applications. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, copper-doped TiO2 nanoparticles with different molar concentrations of copper precursor were synthesized via sol-gel technique. The effects of copper doping on the properties of TiO2 were analyzed systematically, and it was found that 0.1 M concentration of Cu was the optimum dopant concentration for DSSC and photocatalytic applications.