Performance of simple green synthesized Ag incorporated TiO2 nanoparticles based photoanodes by doctor-blade coating as working electrodes for dye sensitized solar cells

In this work, TiO2 and Ag doped TiO2 nanoparticles with different concentrations of Ag (0.01 M, 0.03 M, and 0.05 M) were synthesized by facile green synthesis method using grapefruit extract as solvent/reducing agent. X-ray diffraction patterns and the Raman spectra of the prepared material exhibited anatase phase with tetragonal crystal structure. No specific peaks corresponding to Ag nanoparticles were observed, which further confirms the Ag doping in TiO2. FESEM images reveal the nanorods and spherical shaped morphology of the TiO2 and Ag-TiO2 nanoparticles respectively. UV–Visible spectrum illustrates that absorption edge was shifted towards the visible region and from the photoluminescence spectroscopy quench in the fluorescence intensity was observed for the Ag doped TiO2 samples compared to bare TiO2 sample. Using the prepared TiO2 nanoparticles and Ag doped TiO2 nanoparticles, two different dyes such as natural dye and commercial dye (N719) as sensitizers, photo anodes were prepared. DSSCs were constructed using the prepared photoanodes, and its performance was examined. The silver doped TiO2 nanoparticle showed an efficiency η of 2.66% for MK dye and 6.42% for N719 dye with 0.03 M of silver doping. Improvement of the visible light absorption and the decrease in photogenerated electron hole pair recombination, increment of the oxygen vacancy in the Ag-TiO2 are found to be the key factors for the enhancement of the electrical properties of the DSSCs.