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.