Development of self-supporting catalyst based on bionic honeycomb communication channel from biomass cork waste for hydrogen evolution

Abstract

It is a great challenge to achieve an efficient hydrogen evolution reaction (HER) in the alkaline medium. Multi-layer functional carbon can provide abundant anchor points for metal nanostructures, showing great potential in improving the catalytic activity of electrolyzed water in the alkaline medium. Inspired by honeybee hives, an efficient hydrogen evolution electrode (RuNi-LMH@NCNT/CW) is developed by structuring multi-directional N-doped carbon nanotubes on porous carbonized cork (CW), which encapsulates Ru/RuNi nanoparticles uniformly grown on NiO/Ni(OH)2 nanostructures. Interestingly, the whole encapsulation of NiO/Ni(OH)2 nanostructured doped Ru/RuNi nanoparticles by carbon nanotubes are obtained. The exposed active edges of multilayer porous nanostructures and the high conductivity of the carbonized cork jointly improve the electrocatalytic performance of HER. Specifically, the RuNi-LMH@NCNT/CW electrode shows an over potential as low as 67 mV, achieves excellent HER activity with a current density of 10 mA cm−2 in 1 M KOH solution, and illustrates a low Tafel slope of 41.3 mV dec−1, having excellent stability in alkaline medium. This study provides a bionic composite structure for electrolyzing water to produce hydrogen. In addition, to a certain extent, this study solves the problem that it is difficult to load active particles caused by the cork sealing cell structure.