NiO-decorated mesoporous TiO2 flowers for an improved photovoltaic dye sensitized solar cell

Abstract

Reducing light-induced e–h recombination is important for a dye sensitized solar cell (DSSC); the p-type NiO component in TiO₂–NiO nanoparticles was reported to significantly decrease charge recombination, but its photovoltaic efficiency remains below 4% owing to a small surface area. In this work, we used a one-pot self-assembly process to fabricate flower-like mesoporous TiO₂ decorated by NiO oxides, employing a pluronic polymer P123 as a structure directing and pore forming agent. The flower-like porous TiO₂–NiO nanoparticles (F–TiO₂–NiO NPs), possessing a high BET surface of 130 m² g⁻¹, are first used as a photoanode in DSSCs. These hybrid nanoparticles, decorated with NiO islands, are beneficial for improving photocurrent by increasing dye absorption and suppressing electron–hole recombination. The optimized F–TiO₂–NiO NP anode (10 μm thick) achieved a power conversion efficiency of 8.20%, which is 26% and 47% higher than pristine flower-like TiO₂ and commercially available P25 anodes, respectively. This efficiency is the highest among the reported TiO₂–NiO hybrid anodes.