Comparison between Bi₂WO₆ and\nTiO₂ Photoanodes in Dye-Sensitized Solar Cells: Experimental\nand Computational Studies

Abstract

Dye-sensitized solar cells (DSSCs) demonstrate a clean and cheap\ntechnology to harness solar energy efficiently and have been studied\nin a large scale for safe and reliable energy supply. This research\nfocuses on the experimental and computational study of DSSCs based\non a different and novel metal oxide, bismuth tungstate (Bi₂WO₆), semiconductor as an electron conductor. This work\nis divided into four main topics: (1) the search for an appropriate\nBi₂WO₆ nanostructure for better dye absorption,\n(2) comparison between Bi₂WO₆ and TiO₂ as photoanodes, (3) the impact of the semiconductor morphology on\nthe performance of DSSCs, and (4) the study of the structural and\ndynamical properties of the dye solution and also the electrolyte\nmixture near electrodes in DSSCs. This study pointed out the poor\nproperties of ruthenium-complex dye as sensitizers for Bi₂WO₆ and the great effect of Bi₂WO₆ surface charge on dye adsorption. The best performance of Bi₂WO₆ DSSC was obtained for morphologies synthesized\nat pH = 1, which can be attributed to the less negative surface charges\nof Bi₂WO₆ nanoparticles. Another important part\nof this paper was devoted to study the electrolyte distribution between\nanode and cathode surfaces for both TiO₂ and Bi₂WO₆ DSSCs. To our knowledge, acetonitrile-based electrolyte\ninteractions with the Bi₂WO₆ photoanode have\nnot been explored to date.