Hierarchical Nitrogen-doped Mo2C Nanoparticle-in-microflower Electrocatalyst: in Situ Synthesis and Efficient Hydrogen-evolving Performance in Alkaline and Acidic Media

Herein, a novel 6 similar to 9 nm nitrogen-doped Mo2C nanoparticles (Mo2C P) homogeneously decorated on 3D porous nitrogen-doped Mo2C microflowers (Mo2C F) were prepared in situ to form 0D/3D Mo2C P/Mo2C F. This special structure combines the advantages of Mo2C P and porous Mo2C F to provide a high density of reaction sites and facilitate the diffusion of electrolyte and hydrogen. Mo2C P/Mo2C F exhibits excellent HER performance in both alkaline and acidic solutions. It only requires an overpotential of 96 and 118 mV to achieve a current density of 10 mA cm(-2)(eta(10)) in 1.0 M KOH and 0.5 M H2SO4, respectively. Moreover, it works better than commercial Pt/C at high current densities in 1.0 M KOH. The Tafel slopes are less than 50 mV/dec in both media, suggesting an obviously fast HER kinetics. Additionally, this study presents a universally applicable method to prepare MxC P/Mo2C F (M=Fe, Co, V) for different applications.