Performance of TiO2 nanoparticles synthesized by microwave and solvothermal methods as photoanode in dye-sensitized solar cells (DSSC)

Abstract

In this work, a direct comparison of the properties of the TiO2 nanoparticles prepared by microwave and solvothermal methods were carried out and its performance as photoanode in dye-sensitized solar cells (DSSC) was analyzed. Though previously some works exist on the preparation of TiO2 nanoparticles by solvothermal or microwave methods, they could not be compared directly as the experiment conditions such as choice of solvent, precursors and reaction temperatures were not virtually same. Herein, TiO2 nanoparticles were synthesized by microwave and solvothermal methods using the same initial precursors and properties of the prepared nanoparticles were compared. From the X-ray diffraction pattern and Raman analysis, the prepared nanoparticles in both the cases were found to be of anatase phase. Optical properties and its carrier lifetime were studied using UV-Vis absorption, photoluminescence (PL) analysis and PL lifetime studies, respectively. Further, its morphology analyzed using scanning electron microscope (SEM) and transmission electron microscope (TEM) images, and SAED (selected area electron diffraction) patterns reveals the polycrystalline nature of the prepared nanoparticles. The surface area and the pore size distribution were studied using BET (Brunauer-Emmett-Teller) and BJH (Barrett-Joyner-Halenda) analysis, which revealed its mesoporous nature and uniform pore distribution. The chemical states of the prepared nanoparticles were further characterized using X-ray photoelectron spectroscopy. The DSSC was fabricated using the prepared TiO2 nanoparticles as photoanodes. Further, the power conversion efficiency and the electron transport properties were analyzed.