Abundant Vanadium Diboride with Graphene-like Boron layers for Hydrogen Evolution

We report on the design of abundant and highly active VB₂ for hydrogen production. Density functional theory (DFT) calculations have predicted very high HER activity of the graphene-like B-layer, the V-terminated {100} layer, and the mixed V/B-terminated {101} layer of VB₂. Bulk samples and nanoparticles of VB₂ were synthesized and tested for their HER performance. The results indicate that both bulk and nano-VB₂ are active for HER, consistent with theoretical predictions. In addition, the HER activity of VB₂ is significantly increased at the nanoscale if compared to the bulk, reaching an overpotential of 192 mV at 10 mA/cm² current density. Increased surface area and higher density of active sites are responsible for the higher nanoscale activity, making nano-VB₂ the best HER boride to date in terms of abundance, stability, and activity in acidic solution.