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

In the present work, copper-doped TiO 2 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 TiO 2 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 TiO 2 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 TiO 2 with increasing the Cu concentration. The bandgap values of the Cu–TiO 2 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 TiO 2 as a photoanode without treatment of any scattering layer and we have obtained the maximum efficiency of 3.90% for 0.1 M Cu–TiO 2 (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 TiO 2 which was suitable for DSSC and photocatalytic applications. • Synthesis of Cu–TiO 2 nanoparticles via sol-gel technique. • Effect of Cu conc. on structural, optical, morphological and electrical properties of TiO 2 nanoparticles was analyzed. • The degradation of Rhodamine-B dye by Cu–TiO 2 nanoparticles was analyzed. • The photoanodes of DSSC was fabricated using Cu-doped TiO 2 nanoparticles. • A maximum efficiency of 97.12% and 3.90% obtained by 0.1 M Cu–TiO 2 nanoparticles for Photocatalytic and DSSC applications.