Flexible, Freestanding, and Functional SiO2 Nanofibrous Mat for Dye-Sensitized Solar Cell and Photocatalytic Dye Degradation

In this work, we investigate the SiO 2 nanofibrous nonwoven mat prepared by electrospinning as a porous and high-temperature durable substrate for preparation of the freestanding, flexible, and multifunctional composites. The neat SiO 2 nanofibrous nonwoven mat (denoted as SiO 2 –NF) and the SiO 2 mat functionalized with gold nanoparticles (denoted as Au@SiO 2 –NF) were readily prepared by electrospinning of spin dope containing precursors. Subsequently, a patterned layer of TiO 2 nanoparticles was impregnated and transferred into the SiO 2 or Au@SiO 2 –NF nonwoven mats. The freestanding composite mats of TiO 2 nanoparticles and electrospun SiO 2 –NF or Au@SiO 2 –NF (denoted as TiO 2 –NP/SiO 2 –NF or TiO 2 –NP/Au@SiO 2 –NF, respectively) were demonstrated for dye-sensitized solar cells (DSSCs) and photocatalytic dye degradation. By controlling the amount of TiO 2, composite mats with only partially filled TiO 2 nanoparticles on one side were used as photoanode and spacer in DSSCs; the device had an efficiency of 5.31%. Incorporation of Au nanoparticles in the photoanode (TiO 2 –NP/Au@SiO 2 –NF) improved the device performance. The thermally durable and freestanding TiO 2 –NP/SiO 2 –NF or TiO 2 –NP/Au@SiO 2 –NF was also used as readily recyclable and regeneratable material for effective photodegradation of the methylene blue in aqueous solution.