Plasmonic enhancement of low cost mesoporous Fe₂O₃-TiO₂ loaded with palladium, platinum or silver for dye sensitized solar cells (DSSCs)

Graphical abstract: TEM image of metal incorporated with TiO₂ nanoparticles (left side). And in the (right side) is the schematic diagram of the dye sensitized solar cell including the plasmonic metals incorporated with TiO₂ nanoparticles. - Highlights: • Mesoporous Fe₂O₃-TiO₂ nanoparticles (6.5–8.0 nm) have been synthesized via simple hydrothermal route. • TEM results showed a sphere-like structure for the undoped samples and oval-like structure for the doped samples. • EDX and XPS measurements confirmed the presence of the noble metals nanoparticles. • Silver doped sample showed the highest photovoltaic performance. - Abstract: In this article, a low cost mesoporous Fe₂O₃-TiO₂ nanoparticles has been synthesized from Abu Ghalaga ilmenite ore, Egypt using simple hydrothermal route. Meanwhile, silver, platinum and palladium metals nanoparticles from spent catalysts have been extracted and deposited between the anatase TiO₂ particles using in situ reduction step. The as-synthesized samples were characterized by X-ray diffraction (XRD), transmission electron microscopic (TEM), N₂ adsorption–desorption isotherm (S_BET) and X-ray photoelectron spectroscopy (XPS). The as-prepared materials were applied as photoanodes in dye-sensitized solar cells (DSSCs), whose photocurrent–voltage J–V characteristic curves measurements were consistently performed. The 0.5% precious metal doped samples NPs exhibit absorption enhancement over a broad wavelength range due to the excitation of localized surface plasmons (LSPs) at different wavelengths which also exhibited very good and enhanced photovoltaic performance as a result of the strong scattering lightresulting of noticeable enhancement of charge transfer rates. Indeed, the Ag@Fe₂O₃-TiO₂ sample exhibited the maximum overall conversion efficiency (η % = 4.5%) and it can be considered as a cost-effective photoanode for DSSCs.