One-Step Pyrolysis Transformation of Mulberry Leaves Followed by Electrochemical Treatment: Preparing of M (M = Pt, Au) Nanoparticles Incorporated Nitrogen-Doped Carbon Nanoporous Structures as Efficient Electrocatalyst for Hydrogen Evolution Reaction

To facilely develop low-cost and efficient hydrogen evolution electrocatalysts, catalyst with low content of platinum on nitrogen-doped carbon nanoporous structures were prepared for hydrogen evolution reaction (HER). This study firstly demonstrated the one-step pyrolysis transformation of conveniently accessible mulberry leaves to obtain nitrogen-doped nanoporous carbons (N-NPCs) for hydrogen evolution reaction. After electrochemical treatment, the obtained N-NPCs-ET with Pt as counter electrode exhibited an unexpected high hydrogen evolution activity, which had low onset overpotential of 100 mV and a Tafel slope of 60 mV dec−1. N-NPCs-ET maintained catalytic activity for at least 10 h in 0.5 M H2SO4 solution. The enhanced HER performance was relevant to the incorporation of Pt nanoparticles, which were dissolved from anodic Pt counter electrode in acid media and precipitated into cathodic N-NPCs surface again. Moreover, for the first time, we found that with a gold electrode as the counter electrode, Au nanoparticles could be incorporated into N-NPCs by electrochemical treatments and the formed Au nanoparticles decorated N-NPCs possessed efficient catalytic activity toward HER.