AuNRs attached TiO NPs modified by cobalt-imidazolate frameworks as exceptional materials to improve the energy conversion efficiency of dye-sensitized solar cells.

This work reports a significant improvement in both the open-circuit voltage () and current density () of dye-sensitized solar cells (DSSCs) using gold nanorod-modified TiO nanoparticles (TiO/AuNRs) together with a cobalt-imidazolate framework (ZIF-67) as an efficient photoanode. It was demonstrated that adding ZIF-67 (8 wt%) to TiO NPs increased the by 160 mV and by 2.5 times. This observation was described based on the significant increase in the amount of adsorbed dye in the presence of highly porous ZIF-67, which boosts the photoanode's light harvesting. Modifying TiO NPs with AuNRs also caused a remarkable enhancement in (∼ 2.8 times), which can be explained electron transfer between the TiO conduction band and AuNRs. It can result in a more efficient inhibiting effect on the interfacial charge recombination processes in TiO/AuNRs/ZIF-67 because of the formation of a Schottky barrier at the interface between TiO and Au. These effects were confirmed by the reduction in the photoluminescence intensity of TiO in the presence of AuNRs. More reduction in the photoluminescence intensity was observed when ZIF-67 was added. The prepared photoanode showed an outstanding improvement in the overall efficiency of the DSSC () to 8.38% compared to the bare TiO-based photoanode (1.83%). The notable improvement in the TiO/AuNRs/ZIF-67 performance confirmed its practicality for high-efficiency DSSCs.