Three-dimensional porous vanadium nitride nanoribbon aerogels as Pt-free counter electrode for high-performance dye-sensitized solar cells

• 3D PVNNRAs are prepared by a combination of hydrothermalization and nitridation.
• 3D PVNNRAs are successfully demonstrated as efficient counter electrode in DSCs.
• The electrocatalytic activity of PVNNRA electrode is comparable to that of Pt electrode.
• The DSC with PVNNRA counter electrode achieves a conversion efficiency of 7.05%.

Three-dimensional (3D) porous vanadium nitride nanoribbon aerogels (PVNNRAs) are prepared by hydrothermal synthesis and subsequent nitridation in ammonia/argon atmosphere and investigated as Pt-free counter electrode in dye-sensitized solar cells (DSCs). 3D porous nanoribbon aerogel can simultaneously offer more electrocatalytic active sites, a fast electron-transport pathway, and a favorable electrolyte diffusion channel, which endows the PVNNRA electrode with high electrocatalytic activity for the reduction of I3−. Under full-sun illumination (AM 1.5, 100 mW cm−2), the DSC fabricated with PVNNRA counter electrode achieves a conversion efficiency of 7.05%, which is comparable to that of DSCs fabricated with Pt counter electrode. In addition, the PVNNRA electrode exhibits good stability in I−/I3− redox electrolyte. Thus, 3D PVNNRAs can be considered as a cost-effective alternative to Pt as the counter electrode of DSCs.