Organizing a post fuel cell economy will require the prior development of sustainable energy carriers. Hydrogen is expected to play a significant role in this direction, being the most efficient one, thus nowadays it exists an emerging demand regarding its production. Green hydrogen produced by water splitting produces zero carbon emissions but requires the use of expensive catalysts. Therefore, the demand for efficient and economical catalysts is constantly growing, Transition metal carbides, and especially Mo 2 C, have attracted a lot of attention since they are earth-abundant and hold promises for efficient performance towards the hydrogen evolution reaction. The present study presents a bottom-up approach for the deposition of Mo carbides nanostructures on vertical graphene nanowalls templates, combining chemical vapour deposition, magnetron sputtering and thermal annealing processes. Results highlight the importance of adequate loading of the graphene templates with the optimum amount of the Mo carbides, to enrich the available active sites. The resulting compounds present exceptional activities towards HER in acidic media, requiring overpotentials of 85 mV at -10 mA/cm 2, and demonstrating a Tafel slope of 56 mV/dec. These results are expected to pave the path toward the design of novel nanostructures based on the decoration of nanocatalysts on three-dimensional graphene templates.