Nitrogen doping has become a fundamental approach to
enhance the
catalytic performance of carbon materials across various applications.
The introduction of nitrogen creates defects and active sites, promoting
the formation of small metal particles and strengthening the metal–support
interaction within carbon materials. However, the challenge lies in
developing sustainable and cost-effective methods for synthesizing
nitrogen-doped carbon materials. In this study, we present a sustainable
approach for the synthesis of ruthenium on nitrogen-doped carbon catalysts
(Ru-CCP) using chitosan as a nitrogen and carbon source. Unlike traditional
methods, our process avoids the use of additional nitrogen precursors
and templates, streamlining the synthesis while using a renewable
resource. The synthesized material exhibits an exceptional performance
in the electrochemical hydrogen evolution reaction (HER) in alkaline
conditions by achieving a current density of 25 mA cm–2 at an impressively low overpotential of 46 mV, outperforming Pt/C
under similar conditions. The detailed studies on structural and electronic
properties of the materials using X-ray absorption spectroscopy (XAS),
X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and
transmission electron microscopy (TEM) revealed that the remarkable
catalytic activity is upheld by the unique interplay between Ruδ+ and surface nitrogen moieties, notably pyridinic and
pyrrolic nitrogen. Here, we demonstrate the control of particle size
and electronic environment around the metal atom via the interaction
of nitrogen and unravel the role of nitrogen doping in tuning the
catalytic performance. In addition, this work offers insights into
efficient HER catalyst design and emphasizes the potential of biomass-derived
materials like chitosan in advancing clean hydrogen production for
renewable energy applications.