Tuning anatase-rutile phase transition temperature : TiO2/SiO2 nanoparticles applied in dye-sensitized solar cells

• Autor(a) principal: Cardoso, Billy Nunes
• Data de Publicação: 2019
• Outros Autores: Kohlrausch, Emerson Cristofer, Laranjo, Marina Teixeira, Benvenutti, Edilson Valmir, Balzaretti, Naira Maria, Arenas, Leliz Ticona, Santos, Marcos José Leite, Costa, Tania Maria Haas
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/200525
• topic: Dióxido de titânio; Dióxido de silício; Difração de raios X; Espectroscopia Raman; Tratamento térmico; Células solares

TiO2/SiO2 nanoparticles with 3, 5, and 10 molar percent of silica, were synthesized by hydrothermal method and characterized by SEM, TEM, N2 adsorption-desorption isotherms, X-ray diffraction, and Raman and UV-Vis spectroscopy. While pristine TiO2 thermally treated at 500°C presents a surface area of 36 m2g-1(±10 m2g-1), TiO2/SiO2 containing 3, 5, and 10 molar percent of silica present surface areas of 93, 124, and 150 m2g-1(±10 m2g-1), respectively. SiO2is found to form very small amorphous domains well dispersed in the TiO2 matrix. X-ray diffraction and Raman spectroscopy data show that anatase-to-rutile phase transition temperature is delayed by the presence of SiO2, enabling single-anatase phase photoanodes for DSSCs. According to the I×V measurements, photoanodes with 3% of SiO2 result in improved efficiency, which is mainly related to increasedsurface area and dye loading. In addition, the results suggest a gain in photocurrent related to the passivation of defects by SiO2