Efficient dye-sensitized solar cell from spiny polyaniline nanofiber counter electrode

•Spiny polyaniline nanofibers are grown on Pt layer by a current density control method.•The electrocatalytic activity has been significantly enhanced.•A promising power conversion efficiency of 7.66% is recorded.•The new structure of polyaniline nanofibers are instructive in designing robust DSSCs.

We demonstrate here the growth of spiny polyaniline (PANi) nanofibers on Pt layer through a stepwise control of current density and employment as CE in DSSC. The superiority of this new nanostructure is evaluated by electrochemical characterizations. The resulting PANi nanostructures give an enhanced electrocatalytic activity toward iodides. Careful examination of data and characterizations indicates that the promising properties are impressive to fulfill the task of CEs. A promising power conversion efficiency of 7.66% is obtained in Pt/spiny PANi nanofiber CE in comparison with 5.89% from Pt-only CE and 6.30% from traditional PANi nanofiber CE. This strategy provides new opportunities for fabricating highly efficient DSSCs.